t

~ 128 I~ 2~w ilIiiisectj

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2

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- I 125114

1111116

MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS-1963-A

10 ~W I~~

Iil ~W 22 aW IIj

~11 IW~

I 1111125114

1111116

middot

MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS-1963-A

bull

bull

By W A Douglas and R c Eckhardt

bull Technical Bulletin No 1160

bull UNITED STATES DEPARTMENT OF AGRICULTURE

in cooperation with the

MISSISSIPPI AGRICULTURAL EXPERIMENT STATION

bull

bull

CONTENTS

Review v temlule ~ _ _

Expcrimental proccdure

Evaluation of inbred__

Ealuation of inbrccLq in hybrid combination_

Determination of nlluc of rcibmt hybrid__

SUllllllllT______________ - -

Litenlture citecL_

Pug~

2

2

3

4 bull 11

1)

J3

bull

Wcshingtn D C Is~ued March 1957

For sl~ hl the lUIllrltcnltcnt of J1ncumonts U S Government Priuting Omeo ~shlllgton 25 D C - Price LO conis

bull

bull

bull By W A Douglas entomologist Entomologt Research Branch and R C

Eckhordt agronomist Field Crops Research Branch A9ricultural Research Service

United States Department of Agriculture in cooperation with the Mississippi Agricultural Experiment Station

TIllt COlll lntorlll (lfdiothi8 ((1 (Boddir)) i~ OM of IIH most titsl rud iyt insret pests of (0111 P~I((il111- ill t h( Sou lllllII St it(S Wl11l( it ~(Ii()usl- ciul1ltLps hoth ltI(llt tlild SWllt (011 lnIY par FOl pXllmpl( gJ P(((llt of IIll (flIS (1( inf(sllci 011 llll aylI[l~( ill 2 wiilpl- llsltd YUlilti(s of OIJlII-polLiIlHttd e1lnl (0111 durillg ] 94)-5] at Stnlaquo (olhgp ~Jis Tlw nYlIng nllmblt1 of k(lnll5 dtstloyed P(l (tU ns 26 Bused 011 til( Stntl n-(ln~( yitld of 20 hushpls Jll lVle OWl illt plliod this loss nPPloxinHlt(d ]250000 huhll 101 till 2l~G()O() 1[(1(5 of (0111 glowJI Hnnunll 101 1(((1 ill ~li~issippi The loss of Slpt (0111 glO1l ill th( Slalt fol tlllt (ommllCiaL malkpt in 1948 was ptimntld ui nhout (lll(-lhild of Lilt (rop OJ nbout nlnilldl((l dolLals 1)(1 n(I(

bull In additiOIl to tl]( nrnOlllll of gmin ndllnHy CntllI b til( ltillworm

danUl~lltl ullas nlId Im(J~(IH( holls marip h til( llllnll ](1-l 1hl PH IS tH((ssihh to ltIi1ltns( olgnllisms th( Ii(( -l(jl (ilitllphilu olya (L)) nlld ntlHJ grain ins(d and liuhlr to dnmtl~( b hinls unci w(nlh(Jing (Jig 1) Til( N1Iorm also illjllJ(S (Olll foliagc nnd ttLSs(ls

In n (OOP(JHlin cOlll-impJonm(llt progrnm h- thl l~llitld Stn((s Dl]Jilrtll1ltllt or gricultul( and tl)( ~Jississ[ppi grinrilulllL ExpcrishyJllellt St nlion studi(middots (1( umkltnl(n from 1942 to 195] to d((((nsp lossls C1HISld by (iU-Olm dnlllngl to corn Tilis -or (ollsisld of brpPcling dlnt (0111 hyhrids l(sisltlnt to (lU-Orm )njur- in(hlltiing th(~ pYtlluntiol1 of [lIbnds ilnd s[ngilt- nnci doub]( (TOSS i1dnmiddotids for (Ul01lll

rcsistunc( It nIso (II tnil(d th( isolntion nnd imp1On1lll II ( or rlsisshytnmiddotnt gt[m plnsm llnd its tmllsfpltIH( to (omllulCinl hyhrids hieh offprpd an idrnJ solutioll of th( (uwonn probleUl u- in(lPHSpd -[pM ohtnillPd with ltHlToIUl-resistant hybrids -ould profit thtgt ])10shydu(([ sinep titt [osl nlUld hl no gllntpl for gro-ing rlsislnnt slrnins than Slls(pptibiltmiddot 01(5

1 HubmiUlcl for puigtJiclllioll Aug-ust 27 HJ5U

1

bull

2 TECH~ICAL ]3rLLETl~ 1160 r S DEPT OF AGIU(rLTT~HE

bull

Frm 1 Ear (II Cllrll dmllwd fy tl (lIrll 11111111 th riemiddot (Id ami djj-a llfiall (Jf ilHdlllill hll l pcotf(gt1 11111

REVIEV OF LITERATURE bull Tltl IpittllWC of dllIt lilt II It lO11l to clllllllllIl illfltntioll In

lirt 1Illllltlc II (ollill alld 1llllptoll If C ilt Illli 1111lt 1(llklI Iulld thut plo~llli( or Ipitlllt punllt Imd Iligb ]lInPlllngp of 1I11illfllld IHI lilt littll dallla~1 110111 Inrnu ill illfpt(lt1 pur Bhuwllnlll Biggl I lid ~lIlllillg II ill I 1-1 I (pollld thut (lllll illill(d trunlllil Itllllll1l llitlIl1l to ill~lp 1101 III tIll larlit1 litplashyt UI lnIOIIIl IIitlIl1( 1 llldild III I i1Il to I()u~ tuk lXIIllioll Paillt1 alld BIIIIlllll 1 OllltllIdld tlHlt hibk (Xt(lhioll Wh lIot tIll llll rurto I )i]( alld lllIkill (J) lit(d 1I Illlllll)( Ill ((lIlI B(1t illh(d tlmt tlIlIllit lalW()JIlI I(itall(( til hJlid 1111 abo IPjollld ttal (II ill 1(it1111 coliliJillltlioll hud ItlIIl tu)h 1(IIllI Hild t Itt t lll()l111 I(it ntH Wl) 1I0t 1I lInl roulld ill I()II~-It lIkd tluill III ll-Ji DOllglI Lit illdiltllid thll ItI~~11t alld tigttllCs of hllk lxtlllillll ollld Ilot 1)( dlIHlld(d Oil 10 plllll I (IWlt frottl (alI()tlll dtlllWgl

EXPERIMENTAL PROCEDURE III till 111(middot11101 ItllOIltl-Ilitnllt 0111 lJllllI (Iltl hIP IHIIl

ol)tnillld from illhlld ill yariou tugl or dlllolilllllt ill thl (()III- 1)(Ildillg [l1()gllP Ill thl ~()lllh(tll ~tltt Tht llllifollll (( pollso(d hy tilt ~()llthlIl1 (Olll ImpIOIpIl(lll (0111(1111(( hHYI I)((ll lxtuni1ll(1 Iot or th(1lt Inl (olitailllll siJl~I IIO of lit h((

J1t illhll(ls with thl hlt 0111 (llll III tdllitioJl Ilutn (lll llltl( IntI (otJl BpI [lIlmcls han 1llI1I oiJulillld 1I IlI I Oll Iruill ftUlll PIIml foni~1l lOllll t Ii(

10[ or till llltlllit1 IXllllill(d lws IWIIl ~I() II It t 11 or tPOI( of Ihl IXIllliJll(llt tlltiolb ill Iiiippi lIumiddotnlly tIll 111111 Iatiull It ~(nl( (oll(~( nnd th( ])Itl 15tllllt ~1lti()llIt ~lIlJ1lill( Tit lnlh mH t (rilll 1 ttsl (I at 11 011 ~JlliJlg 11 lid n t ~t alt ( ollpgl 0 I ~t IIlll ill I COIJl has also htPll tlHU((1 It fip otllll tXPliJIl(llt tatiolb ill tIlt ~tH[( as (11 as Oil (IIt1 dlltH plllliatioll lwkll til tht InshyIHlllHl and Louiiullt gli(tlltlllul EqHlillllnt ~IHtioll It f1()l1 llltllly of tIll I t(-llltt II Iillf inglemiddot (101 101 ll()tlIl tlltlil

Ilalie Jllllldl~ ill jlalflIlh~I~ ]Ir In Litlllllll (itd p la

bull

3

bull

bull

bull

bull

DENT CORN INBREDS AND HYBRIDS RESISTANT TO CORN EARWORM

Oe11erI111- the corn was plun ted in 40- b- 40-i11(h hills in 2- by 10shyhill plots thuUltcl to 2 or 3 stalks per hill iUlcl replicated a to 6 times at eaeh of s(verul loeations En tries were usunlly grouped into (arly) midsenson and late strains The corn ltceiyed nmple fertilizer It nlS cultiyatecl in the lIsuulmnnl1er amI alloncl to open-pollinab

Ilesistuute of eorn en1S to fC((lil1g b- the ean-orm wns one of the rrit0rin lIs((l in sel(ding inhreds for furtlur l1S( in the br(eding program 11 t State COlJ0gC In brCds pnpotCll t for eaJwOlln r(Sistllll(l were 1I5((1 or they were closs(d with illhrecls superior jll other charactershyisti(s but poor in earworm ](sistnncl From sueh cross(s inhrecls WNt selected for (nlworm resistanC( as well us for good yield lodging ]rsistaJl( rnd otlWl desimhl agronomic ehnractLJs

In tll(s( shldies data pre J(cord(d for th lIsual agronomic charshylHkrs and for husk lxknsion heyond the tip of thl tiU) husk tigh t shyness ilm1 u)(et (lmnag( to tht (nrs ltCle t]i( iuflstatiOH wns seypll (n011gh hud dmnngp on young (Olll wns somCtim(s Jlotpd Datn qre also 1((o1cl((l 011 oyiposj(ion hy thc (arwoJm moths on the silks ill plCI((l trsts

111p eOln jn PHell plot nls Juunstlltl SllHlrntply nmI rnell (HI middotus rntrltl tiS follos for rHlWOIlIl (lnmugl

1JlCr of kernel

Jce~ or rill maue dcsrollcd RlllillU pc III lrulioll prr car

(11 o Il I J 2 II L 3middot1 L 15 5 130

1 0 ilffalioll

Thl HT(rage dt1l1U1W Ill tin~ Jlll (11(11 plot as (ld(IJl1iJ1pd l)y multishyplying tlH ruting h- the l1uml)(1 or (urs ginn thn rating ndding the plocluCts nJl(l c[iyjcling b the otni mnnlwl of ears From the uY(rng( nl (ing 101 (Hell plot lIns ohtuul(ltl ntlt a (nlgp for the entry ill the tpst TIll ]wlePJltnglt ofinfcst(d etlrs WHS n]so eukuinfc(L

EYALUATION OF INBREDS III 1n4~ n group of 4()) iniJncls W(I( studi(cl ~Iost of th(lll crc

]lot vigorous and (onsNIII(llI- Itld poor par dn-(]opn)(nt pspl(inlly thost ]HlPOtltl1t for long husk Dala (1( tnk(J) OJl pur l(ngtll husk pxt(llsion l)(yon([ thl tip of 1Jp (tl r husk tightmss nJ](l (11l0lJ11

dunulge lImk rXC11Rioll t1lJ1gtcl from -0) to +G7 ind(s T1J( rating of fnrWOllll dlunngp wus diHicult to dllllmill( bN~HUS( 01 thl smull 111lmbll or wCIl-fil]p(l (HIS aJHl tJH fnilul( of SOll1pound iJlfgtnmiddotds to produc( purs ~rost or tlll illhr((ls hnt llid not han N10Ugh PHIS to plrmit tin enn()lJll Ill tillg (1( ha(Il~- dnnlllg(d by till lns(ct 111(1( us ])0 signifirun t (011( In t ion JC W(PJl h usl (xtlllsioll tlnd lurworm dnmng(

In I 947 anothlr group of 314 inb1(rls I1e (sted with llsults similar to those obtuiJ1(d in 1913

From tllp dnttl 011 hoUt groups it yas (ollcludlc that i11b1((ls in h(DlSeh-(s w(n uma tisfneOlY for ill( sudy of el1rWOIJll Jesistl1l1((

4 TECInICAL BULLElIK 1160 U S DEPT OF AGRlCcLTURE

Tests of hybrids run (ontunmiddot(ntl) with the tests of inhrecls making bullup the hybrids indicated that the yalue of an inbred in breeding for resistance can be more reliably and accuratel) d(t(rmin(d b) ratillg the hybrids beenusC of their great(l yigor and more normal deyelopshylllent TIlCrefore thp pra(t1(e of rating inhreds for damage ms disshycontinuCd in 1947 and 11-bri(ls were us(d to det(rmine the preshypoteuC) of inbrCcls for CUlWOJm resistance Sing]p- doublp- 3-way and top-cross bybrids ere che~ked but almost all the data giY(l1 here were based 011 sing]p-crosio hybrids

EVALUATION OF INBREDS IN HYBRID COMBINATIONS

)fallY inbrCCls pre rated for J(sisltllc( to 1he (orn eUlworm in the 1(sts of h)7brids ill Mississippi Alnhmna and Louisinnn from 1943 to 1951 Before an 1n1)1((1 was ginn t (hfinite lating it was 1esteCt in (ombinMioll ~-~ih 01hel illlJJ(ds ill at Ittlst G ](plienlions in 2 or mol( loeations Theldon although tlHlP has b((ll SOJllP Yaliation in bull the in1(l1si1)- of the infcstMion the possihilityof (JTor in rating bns hNIl lec1u((d to ~ minimum AJthougb most inb(ds -(J( mtpc1 Oll th(ir (tl(tiOllS in singhmiddot-ClosS (om1gtin[llions doublt-(ross hybrids wJp fllso ObSP1Y(d (w~n though it WtlS dif1icult to tmce the infiu(ncp of allY 1 illhrecl dlPlP as l1lt111- as 4 inbrerls W(I( iny01(lt1

The datn for tilt inhnds lms((l 011 th(ir JHdoJmnI1(e in 1I1)1id comhinntiolls hnyl h(el) n11gtitraIih- diyickd into fOllr IlSistmle( ([LLCgories whi(1I fire d(s(1ilwd as ollows

RIIIt mlafllll evlllJiSrWfII ~ 1mOllnt uf Ralisrllwe lta(YOffl ill curs dUflWfU to Ctlf-

II ighl~ lPltbtaut Loll Kli~ht R(middotistanL ___ [oc1(ralp Klil-hl IntplnHdillte Jocllnlt IodprtllP KlIscPptilJlp High ~(YLrp

Th( following iul)l(ds hUT( 1gt((11 dnssiJiltd [l((ordillg to th(se lCsislanc( categori(s

Resista1lce caltjyory Highly IPSistllnt

hitp __ _ Ydlow

llcsistllnt bullWhitl _ F~ 14 Cl~205 CE24i (11 HEn] LSi LHj Jp30fl Ip31 Jp)35 TIOl

YlUOW __ FR F44 fpl Ip410 Ip42(i III tlllIlpdiate

Whitc __ _ GT~1 UT5 12-2 LlO L25 lA4 LflO Ul1 [p305 [p3J1 xc) XCH xCi XC45 )Ci4 XC75 R30 1-01[ U121 ]])3~R 113485

CLi 15 Fi CEaR GT1Gfll GTJGDIJ GT17) W4D Kb50 K Y5~7 KY~ L 101 L510 L515 1578 [p40~ [p4]2 [p4J4 ip428 XCi XC13 XCS~ XCS3 0-18 1204

KU(pr)( iblr h ittmiddot CGG CU3 H-21 H-22 JI- J[20~ KH K55 KG4

KI~2 KI]3 Ky27 K~4[) Ky5S KySH Kyll4 L13 124 125 102 LSG LI03 1021A fo~2 [p~Ol [ p303 1 pa07 1 p315 Ip317 [ pal fI XC3f1 XCH H7 HJ I lUi R23 110 113 114 118 161 TR3 185 T10) Ill] Tll3 fIlii Ili5A 33-1 G 5340 5370 53SfI 54H 5437

bull

bull

bull

By W A Douglas and R c Eckhardt

bull Technical Bulletin No 1160

bull UNITED STATES DEPARTMENT OF AGRICULTURE

in cooperation with the

MISSISSIPPI AGRICULTURAL EXPERIMENT STATION

bull

bull

CONTENTS

Review v temlule ~ _ _

Expcrimental proccdure

Evaluation of inbred__

Ealuation of inbrccLq in hybrid combination_

Determination of nlluc of rcibmt hybrid__

SUllllllllT______________ - -

Litenlture citecL_

Pug~

2

2

3

4 bull 11

1)

J3

bull

Wcshingtn D C Is~ued March 1957

For sl~ hl the lUIllrltcnltcnt of J1ncumonts U S Government Priuting Omeo ~shlllgton 25 D C - Price LO conis

bull

bull

bull By W A Douglas entomologist Entomologt Research Branch and R C

Eckhordt agronomist Field Crops Research Branch A9ricultural Research Service

United States Department of Agriculture in cooperation with the Mississippi Agricultural Experiment Station

TIllt COlll lntorlll (lfdiothi8 ((1 (Boddir)) i~ OM of IIH most titsl rud iyt insret pests of (0111 P~I((il111- ill t h( Sou lllllII St it(S Wl11l( it ~(Ii()usl- ciul1ltLps hoth ltI(llt tlild SWllt (011 lnIY par FOl pXllmpl( gJ P(((llt of IIll (flIS (1( inf(sllci 011 llll aylI[l~( ill 2 wiilpl- llsltd YUlilti(s of OIJlII-polLiIlHttd e1lnl (0111 durillg ] 94)-5] at Stnlaquo (olhgp ~Jis Tlw nYlIng nllmblt1 of k(lnll5 dtstloyed P(l (tU ns 26 Bused 011 til( Stntl n-(ln~( yitld of 20 hushpls Jll lVle OWl illt plliod this loss nPPloxinHlt(d ]250000 huhll 101 till 2l~G()O() 1[(1(5 of (0111 glowJI Hnnunll 101 1(((1 ill ~li~issippi The loss of Slpt (0111 glO1l ill th( Slalt fol tlllt (ommllCiaL malkpt in 1948 was ptimntld ui nhout (lll(-lhild of Lilt (rop OJ nbout nlnilldl((l dolLals 1)(1 n(I(

bull In additiOIl to tl]( nrnOlllll of gmin ndllnHy CntllI b til( ltillworm

danUl~lltl ullas nlId Im(J~(IH( holls marip h til( llllnll ](1-l 1hl PH IS tH((ssihh to ltIi1ltns( olgnllisms th( Ii(( -l(jl (ilitllphilu olya (L)) nlld ntlHJ grain ins(d and liuhlr to dnmtl~( b hinls unci w(nlh(Jing (Jig 1) Til( N1Iorm also illjllJ(S (Olll foliagc nnd ttLSs(ls

In n (OOP(JHlin cOlll-impJonm(llt progrnm h- thl l~llitld Stn((s Dl]Jilrtll1ltllt or gricultul( and tl)( ~Jississ[ppi grinrilulllL ExpcrishyJllellt St nlion studi(middots (1( umkltnl(n from 1942 to 195] to d((((nsp lossls C1HISld by (iU-Olm dnlllngl to corn Tilis -or (ollsisld of brpPcling dlnt (0111 hyhrids l(sisltlnt to (lU-Orm )njur- in(hlltiing th(~ pYtlluntiol1 of [lIbnds ilnd s[ngilt- nnci doub]( (TOSS i1dnmiddotids for (Ul01lll

rcsistunc( It nIso (II tnil(d th( isolntion nnd imp1On1lll II ( or rlsisshytnmiddotnt gt[m plnsm llnd its tmllsfpltIH( to (omllulCinl hyhrids hieh offprpd an idrnJ solutioll of th( (uwonn probleUl u- in(lPHSpd -[pM ohtnillPd with ltHlToIUl-resistant hybrids -ould profit thtgt ])10shydu(([ sinep titt [osl nlUld hl no gllntpl for gro-ing rlsislnnt slrnins than Slls(pptibiltmiddot 01(5

1 HubmiUlcl for puigtJiclllioll Aug-ust 27 HJ5U

1

bull

2 TECH~ICAL ]3rLLETl~ 1160 r S DEPT OF AGIU(rLTT~HE

bull

Frm 1 Ear (II Cllrll dmllwd fy tl (lIrll 11111111 th riemiddot (Id ami djj-a llfiall (Jf ilHdlllill hll l pcotf(gt1 11111

REVIEV OF LITERATURE bull Tltl IpittllWC of dllIt lilt II It lO11l to clllllllllIl illfltntioll In

lirt 1Illllltlc II (ollill alld 1llllptoll If C ilt Illli 1111lt 1(llklI Iulld thut plo~llli( or Ipitlllt punllt Imd Iligb ]lInPlllngp of 1I11illfllld IHI lilt littll dallla~1 110111 Inrnu ill illfpt(lt1 pur Bhuwllnlll Biggl I lid ~lIlllillg II ill I 1-1 I (pollld thut (lllll illill(d trunlllil Itllllll1l llitlIl1l to ill~lp 1101 III tIll larlit1 litplashyt UI lnIOIIIl IIitlIl1( 1 llldild III I i1Il to I()u~ tuk lXIIllioll Paillt1 alld BIIIIlllll 1 OllltllIdld tlHlt hibk (Xt(lhioll Wh lIot tIll llll rurto I )i]( alld lllIkill (J) lit(d 1I Illlllll)( Ill ((lIlI B(1t illh(d tlmt tlIlIllit lalW()JIlI I(itall(( til hJlid 1111 abo IPjollld ttal (II ill 1(it1111 coliliJillltlioll hud ItlIIl tu)h 1(IIllI Hild t Itt t lll()l111 I(it ntH Wl) 1I0t 1I lInl roulld ill I()II~-It lIkd tluill III ll-Ji DOllglI Lit illdiltllid thll ItI~~11t alld tigttllCs of hllk lxtlllillll ollld Ilot 1)( dlIHlld(d Oil 10 plllll I (IWlt frottl (alI()tlll dtlllWgl

EXPERIMENTAL PROCEDURE III till 111(middot11101 ItllOIltl-Ilitnllt 0111 lJllllI (Iltl hIP IHIIl

ol)tnillld from illhlld ill yariou tugl or dlllolilllllt ill thl (()III- 1)(Ildillg [l1()gllP Ill thl ~()lllh(tll ~tltt Tht llllifollll (( pollso(d hy tilt ~()llthlIl1 (Olll ImpIOIpIl(lll (0111(1111(( hHYI I)((ll lxtuni1ll(1 Iot or th(1lt Inl (olitailllll siJl~I IIO of lit h((

J1t illhll(ls with thl hlt 0111 (llll III tdllitioJl Ilutn (lll llltl( IntI (otJl BpI [lIlmcls han 1llI1I oiJulillld 1I IlI I Oll Iruill ftUlll PIIml foni~1l lOllll t Ii(

10[ or till llltlllit1 IXllllill(d lws IWIIl ~I() II It t 11 or tPOI( of Ihl IXIllliJll(llt tlltiolb ill Iiiippi lIumiddotnlly tIll 111111 Iatiull It ~(nl( (oll(~( nnd th( ])Itl 15tllllt ~1lti()llIt ~lIlJ1lill( Tit lnlh mH t (rilll 1 ttsl (I at 11 011 ~JlliJlg 11 lid n t ~t alt ( ollpgl 0 I ~t IIlll ill I COIJl has also htPll tlHU((1 It fip otllll tXPliJIl(llt tatiolb ill tIlt ~tH[( as (11 as Oil (IIt1 dlltH plllliatioll lwkll til tht InshyIHlllHl and Louiiullt gli(tlltlllul EqHlillllnt ~IHtioll It f1()l1 llltllly of tIll I t(-llltt II Iillf inglemiddot (101 101 ll()tlIl tlltlil

Ilalie Jllllldl~ ill jlalflIlh~I~ ]Ir In Litlllllll (itd p la

bull

3

bull

bull

bull

bull

DENT CORN INBREDS AND HYBRIDS RESISTANT TO CORN EARWORM

Oe11erI111- the corn was plun ted in 40- b- 40-i11(h hills in 2- by 10shyhill plots thuUltcl to 2 or 3 stalks per hill iUlcl replicated a to 6 times at eaeh of s(verul loeations En tries were usunlly grouped into (arly) midsenson and late strains The corn ltceiyed nmple fertilizer It nlS cultiyatecl in the lIsuulmnnl1er amI alloncl to open-pollinab

Ilesistuute of eorn en1S to fC((lil1g b- the ean-orm wns one of the rrit0rin lIs((l in sel(ding inhreds for furtlur l1S( in the br(eding program 11 t State COlJ0gC In brCds pnpotCll t for eaJwOlln r(Sistllll(l were 1I5((1 or they were closs(d with illhrecls superior jll other charactershyisti(s but poor in earworm ](sistnncl From sueh cross(s inhrecls WNt selected for (nlworm resistanC( as well us for good yield lodging ]rsistaJl( rnd otlWl desimhl agronomic ehnractLJs

In tll(s( shldies data pre J(cord(d for th lIsual agronomic charshylHkrs and for husk lxknsion heyond the tip of thl tiU) husk tigh t shyness ilm1 u)(et (lmnag( to tht (nrs ltCle t]i( iuflstatiOH wns seypll (n011gh hud dmnngp on young (Olll wns somCtim(s Jlotpd Datn qre also 1((o1cl((l 011 oyiposj(ion hy thc (arwoJm moths on the silks ill plCI((l trsts

111p eOln jn PHell plot nls Juunstlltl SllHlrntply nmI rnell (HI middotus rntrltl tiS follos for rHlWOIlIl (lnmugl

1JlCr of kernel

Jce~ or rill maue dcsrollcd RlllillU pc III lrulioll prr car

(11 o Il I J 2 II L 3middot1 L 15 5 130

1 0 ilffalioll

Thl HT(rage dt1l1U1W Ill tin~ Jlll (11(11 plot as (ld(IJl1iJ1pd l)y multishyplying tlH ruting h- the l1uml)(1 or (urs ginn thn rating ndding the plocluCts nJl(l c[iyjcling b the otni mnnlwl of ears From the uY(rng( nl (ing 101 (Hell plot lIns ohtuul(ltl ntlt a (nlgp for the entry ill the tpst TIll ]wlePJltnglt ofinfcst(d etlrs WHS n]so eukuinfc(L

EYALUATION OF INBREDS III 1n4~ n group of 4()) iniJncls W(I( studi(cl ~Iost of th(lll crc

]lot vigorous and (onsNIII(llI- Itld poor par dn-(]opn)(nt pspl(inlly thost ]HlPOtltl1t for long husk Dala (1( tnk(J) OJl pur l(ngtll husk pxt(llsion l)(yon([ thl tip of 1Jp (tl r husk tightmss nJ](l (11l0lJ11

dunulge lImk rXC11Rioll t1lJ1gtcl from -0) to +G7 ind(s T1J( rating of fnrWOllll dlunngp wus diHicult to dllllmill( bN~HUS( 01 thl smull 111lmbll or wCIl-fil]p(l (HIS aJHl tJH fnilul( of SOll1pound iJlfgtnmiddotds to produc( purs ~rost or tlll illhr((ls hnt llid not han N10Ugh PHIS to plrmit tin enn()lJll Ill tillg (1( ha(Il~- dnnlllg(d by till lns(ct 111(1( us ])0 signifirun t (011( In t ion JC W(PJl h usl (xtlllsioll tlnd lurworm dnmng(

In I 947 anothlr group of 314 inb1(rls I1e (sted with llsults similar to those obtuiJ1(d in 1913

From tllp dnttl 011 hoUt groups it yas (ollcludlc that i11b1((ls in h(DlSeh-(s w(n uma tisfneOlY for ill( sudy of el1rWOIJll Jesistl1l1((

4 TECInICAL BULLElIK 1160 U S DEPT OF AGRlCcLTURE

Tests of hybrids run (ontunmiddot(ntl) with the tests of inhrecls making bullup the hybrids indicated that the yalue of an inbred in breeding for resistance can be more reliably and accuratel) d(t(rmin(d b) ratillg the hybrids beenusC of their great(l yigor and more normal deyelopshylllent TIlCrefore thp pra(t1(e of rating inhreds for damage ms disshycontinuCd in 1947 and 11-bri(ls were us(d to det(rmine the preshypoteuC) of inbrCcls for CUlWOJm resistance Sing]p- doublp- 3-way and top-cross bybrids ere che~ked but almost all the data giY(l1 here were based 011 sing]p-crosio hybrids

EVALUATION OF INBREDS IN HYBRID COMBINATIONS

)fallY inbrCCls pre rated for J(sisltllc( to 1he (orn eUlworm in the 1(sts of h)7brids ill Mississippi Alnhmna and Louisinnn from 1943 to 1951 Before an 1n1)1((1 was ginn t (hfinite lating it was 1esteCt in (ombinMioll ~-~ih 01hel illlJJ(ds ill at Ittlst G ](plienlions in 2 or mol( loeations Theldon although tlHlP has b((ll SOJllP Yaliation in bull the in1(l1si1)- of the infcstMion the possihilityof (JTor in rating bns hNIl lec1u((d to ~ minimum AJthougb most inb(ds -(J( mtpc1 Oll th(ir (tl(tiOllS in singhmiddot-ClosS (om1gtin[llions doublt-(ross hybrids wJp fllso ObSP1Y(d (w~n though it WtlS dif1icult to tmce the infiu(ncp of allY 1 illhrecl dlPlP as l1lt111- as 4 inbrerls W(I( iny01(lt1

The datn for tilt inhnds lms((l 011 th(ir JHdoJmnI1(e in 1I1)1id comhinntiolls hnyl h(el) n11gtitraIih- diyickd into fOllr IlSistmle( ([LLCgories whi(1I fire d(s(1ilwd as ollows

RIIIt mlafllll evlllJiSrWfII ~ 1mOllnt uf Ralisrllwe lta(YOffl ill curs dUflWfU to Ctlf-

II ighl~ lPltbtaut Loll Kli~ht R(middotistanL ___ [oc1(ralp Klil-hl IntplnHdillte Jocllnlt IodprtllP KlIscPptilJlp High ~(YLrp

Th( following iul)l(ds hUT( 1gt((11 dnssiJiltd [l((ordillg to th(se lCsislanc( categori(s

Resista1lce caltjyory Highly IPSistllnt

hitp __ _ Ydlow

llcsistllnt bullWhitl _ F~ 14 Cl~205 CE24i (11 HEn] LSi LHj Jp30fl Ip31 Jp)35 TIOl

YlUOW __ FR F44 fpl Ip410 Ip42(i III tlllIlpdiate

Whitc __ _ GT~1 UT5 12-2 LlO L25 lA4 LflO Ul1 [p305 [p3J1 xc) XCH xCi XC45 )Ci4 XC75 R30 1-01[ U121 ]])3~R 113485

CLi 15 Fi CEaR GT1Gfll GTJGDIJ GT17) W4D Kb50 K Y5~7 KY~ L 101 L510 L515 1578 [p40~ [p4]2 [p4J4 ip428 XCi XC13 XCS~ XCS3 0-18 1204

KU(pr)( iblr h ittmiddot CGG CU3 H-21 H-22 JI- J[20~ KH K55 KG4

KI~2 KI]3 Ky27 K~4[) Ky5S KySH Kyll4 L13 124 125 102 LSG LI03 1021A fo~2 [p~Ol [ p303 1 pa07 1 p315 Ip317 [ pal fI XC3f1 XCH H7 HJ I lUi R23 110 113 114 118 161 TR3 185 T10) Ill] Tll3 fIlii Ili5A 33-1 G 5340 5370 53SfI 54H 5437

bull

bull

CONTENTS

Review v temlule ~ _ _

Expcrimental proccdure

Evaluation of inbred__

Ealuation of inbrccLq in hybrid combination_

Determination of nlluc of rcibmt hybrid__

SUllllllllT______________ - -

Litenlture citecL_

Pug~

2

2

3

4 bull 11

1)

J3

bull

Wcshingtn D C Is~ued March 1957

For sl~ hl the lUIllrltcnltcnt of J1ncumonts U S Government Priuting Omeo ~shlllgton 25 D C - Price LO conis

bull

bull

bull By W A Douglas entomologist Entomologt Research Branch and R C

Eckhordt agronomist Field Crops Research Branch A9ricultural Research Service

United States Department of Agriculture in cooperation with the Mississippi Agricultural Experiment Station

TIllt COlll lntorlll (lfdiothi8 ((1 (Boddir)) i~ OM of IIH most titsl rud iyt insret pests of (0111 P~I((il111- ill t h( Sou lllllII St it(S Wl11l( it ~(Ii()usl- ciul1ltLps hoth ltI(llt tlild SWllt (011 lnIY par FOl pXllmpl( gJ P(((llt of IIll (flIS (1( inf(sllci 011 llll aylI[l~( ill 2 wiilpl- llsltd YUlilti(s of OIJlII-polLiIlHttd e1lnl (0111 durillg ] 94)-5] at Stnlaquo (olhgp ~Jis Tlw nYlIng nllmblt1 of k(lnll5 dtstloyed P(l (tU ns 26 Bused 011 til( Stntl n-(ln~( yitld of 20 hushpls Jll lVle OWl illt plliod this loss nPPloxinHlt(d ]250000 huhll 101 till 2l~G()O() 1[(1(5 of (0111 glowJI Hnnunll 101 1(((1 ill ~li~issippi The loss of Slpt (0111 glO1l ill th( Slalt fol tlllt (ommllCiaL malkpt in 1948 was ptimntld ui nhout (lll(-lhild of Lilt (rop OJ nbout nlnilldl((l dolLals 1)(1 n(I(

bull In additiOIl to tl]( nrnOlllll of gmin ndllnHy CntllI b til( ltillworm

danUl~lltl ullas nlId Im(J~(IH( holls marip h til( llllnll ](1-l 1hl PH IS tH((ssihh to ltIi1ltns( olgnllisms th( Ii(( -l(jl (ilitllphilu olya (L)) nlld ntlHJ grain ins(d and liuhlr to dnmtl~( b hinls unci w(nlh(Jing (Jig 1) Til( N1Iorm also illjllJ(S (Olll foliagc nnd ttLSs(ls

In n (OOP(JHlin cOlll-impJonm(llt progrnm h- thl l~llitld Stn((s Dl]Jilrtll1ltllt or gricultul( and tl)( ~Jississ[ppi grinrilulllL ExpcrishyJllellt St nlion studi(middots (1( umkltnl(n from 1942 to 195] to d((((nsp lossls C1HISld by (iU-Olm dnlllngl to corn Tilis -or (ollsisld of brpPcling dlnt (0111 hyhrids l(sisltlnt to (lU-Orm )njur- in(hlltiing th(~ pYtlluntiol1 of [lIbnds ilnd s[ngilt- nnci doub]( (TOSS i1dnmiddotids for (Ul01lll

rcsistunc( It nIso (II tnil(d th( isolntion nnd imp1On1lll II ( or rlsisshytnmiddotnt gt[m plnsm llnd its tmllsfpltIH( to (omllulCinl hyhrids hieh offprpd an idrnJ solutioll of th( (uwonn probleUl u- in(lPHSpd -[pM ohtnillPd with ltHlToIUl-resistant hybrids -ould profit thtgt ])10shydu(([ sinep titt [osl nlUld hl no gllntpl for gro-ing rlsislnnt slrnins than Slls(pptibiltmiddot 01(5

1 HubmiUlcl for puigtJiclllioll Aug-ust 27 HJ5U

1

bull

2 TECH~ICAL ]3rLLETl~ 1160 r S DEPT OF AGIU(rLTT~HE

bull

Frm 1 Ear (II Cllrll dmllwd fy tl (lIrll 11111111 th riemiddot (Id ami djj-a llfiall (Jf ilHdlllill hll l pcotf(gt1 11111

REVIEV OF LITERATURE bull Tltl IpittllWC of dllIt lilt II It lO11l to clllllllllIl illfltntioll In

lirt 1Illllltlc II (ollill alld 1llllptoll If C ilt Illli 1111lt 1(llklI Iulld thut plo~llli( or Ipitlllt punllt Imd Iligb ]lInPlllngp of 1I11illfllld IHI lilt littll dallla~1 110111 Inrnu ill illfpt(lt1 pur Bhuwllnlll Biggl I lid ~lIlllillg II ill I 1-1 I (pollld thut (lllll illill(d trunlllil Itllllll1l llitlIl1l to ill~lp 1101 III tIll larlit1 litplashyt UI lnIOIIIl IIitlIl1( 1 llldild III I i1Il to I()u~ tuk lXIIllioll Paillt1 alld BIIIIlllll 1 OllltllIdld tlHlt hibk (Xt(lhioll Wh lIot tIll llll rurto I )i]( alld lllIkill (J) lit(d 1I Illlllll)( Ill ((lIlI B(1t illh(d tlmt tlIlIllit lalW()JIlI I(itall(( til hJlid 1111 abo IPjollld ttal (II ill 1(it1111 coliliJillltlioll hud ItlIIl tu)h 1(IIllI Hild t Itt t lll()l111 I(it ntH Wl) 1I0t 1I lInl roulld ill I()II~-It lIkd tluill III ll-Ji DOllglI Lit illdiltllid thll ItI~~11t alld tigttllCs of hllk lxtlllillll ollld Ilot 1)( dlIHlld(d Oil 10 plllll I (IWlt frottl (alI()tlll dtlllWgl

EXPERIMENTAL PROCEDURE III till 111(middot11101 ItllOIltl-Ilitnllt 0111 lJllllI (Iltl hIP IHIIl

ol)tnillld from illhlld ill yariou tugl or dlllolilllllt ill thl (()III- 1)(Ildillg [l1()gllP Ill thl ~()lllh(tll ~tltt Tht llllifollll (( pollso(d hy tilt ~()llthlIl1 (Olll ImpIOIpIl(lll (0111(1111(( hHYI I)((ll lxtuni1ll(1 Iot or th(1lt Inl (olitailllll siJl~I IIO of lit h((

J1t illhll(ls with thl hlt 0111 (llll III tdllitioJl Ilutn (lll llltl( IntI (otJl BpI [lIlmcls han 1llI1I oiJulillld 1I IlI I Oll Iruill ftUlll PIIml foni~1l lOllll t Ii(

10[ or till llltlllit1 IXllllill(d lws IWIIl ~I() II It t 11 or tPOI( of Ihl IXIllliJll(llt tlltiolb ill Iiiippi lIumiddotnlly tIll 111111 Iatiull It ~(nl( (oll(~( nnd th( ])Itl 15tllllt ~1lti()llIt ~lIlJ1lill( Tit lnlh mH t (rilll 1 ttsl (I at 11 011 ~JlliJlg 11 lid n t ~t alt ( ollpgl 0 I ~t IIlll ill I COIJl has also htPll tlHU((1 It fip otllll tXPliJIl(llt tatiolb ill tIlt ~tH[( as (11 as Oil (IIt1 dlltH plllliatioll lwkll til tht InshyIHlllHl and Louiiullt gli(tlltlllul EqHlillllnt ~IHtioll It f1()l1 llltllly of tIll I t(-llltt II Iillf inglemiddot (101 101 ll()tlIl tlltlil

Ilalie Jllllldl~ ill jlalflIlh~I~ ]Ir In Litlllllll (itd p la

bull

3

bull

bull

bull

bull

DENT CORN INBREDS AND HYBRIDS RESISTANT TO CORN EARWORM

Oe11erI111- the corn was plun ted in 40- b- 40-i11(h hills in 2- by 10shyhill plots thuUltcl to 2 or 3 stalks per hill iUlcl replicated a to 6 times at eaeh of s(verul loeations En tries were usunlly grouped into (arly) midsenson and late strains The corn ltceiyed nmple fertilizer It nlS cultiyatecl in the lIsuulmnnl1er amI alloncl to open-pollinab

Ilesistuute of eorn en1S to fC((lil1g b- the ean-orm wns one of the rrit0rin lIs((l in sel(ding inhreds for furtlur l1S( in the br(eding program 11 t State COlJ0gC In brCds pnpotCll t for eaJwOlln r(Sistllll(l were 1I5((1 or they were closs(d with illhrecls superior jll other charactershyisti(s but poor in earworm ](sistnncl From sueh cross(s inhrecls WNt selected for (nlworm resistanC( as well us for good yield lodging ]rsistaJl( rnd otlWl desimhl agronomic ehnractLJs

In tll(s( shldies data pre J(cord(d for th lIsual agronomic charshylHkrs and for husk lxknsion heyond the tip of thl tiU) husk tigh t shyness ilm1 u)(et (lmnag( to tht (nrs ltCle t]i( iuflstatiOH wns seypll (n011gh hud dmnngp on young (Olll wns somCtim(s Jlotpd Datn qre also 1((o1cl((l 011 oyiposj(ion hy thc (arwoJm moths on the silks ill plCI((l trsts

111p eOln jn PHell plot nls Juunstlltl SllHlrntply nmI rnell (HI middotus rntrltl tiS follos for rHlWOIlIl (lnmugl

1JlCr of kernel

Jce~ or rill maue dcsrollcd RlllillU pc III lrulioll prr car

(11 o Il I J 2 II L 3middot1 L 15 5 130

1 0 ilffalioll

Thl HT(rage dt1l1U1W Ill tin~ Jlll (11(11 plot as (ld(IJl1iJ1pd l)y multishyplying tlH ruting h- the l1uml)(1 or (urs ginn thn rating ndding the plocluCts nJl(l c[iyjcling b the otni mnnlwl of ears From the uY(rng( nl (ing 101 (Hell plot lIns ohtuul(ltl ntlt a (nlgp for the entry ill the tpst TIll ]wlePJltnglt ofinfcst(d etlrs WHS n]so eukuinfc(L

EYALUATION OF INBREDS III 1n4~ n group of 4()) iniJncls W(I( studi(cl ~Iost of th(lll crc

]lot vigorous and (onsNIII(llI- Itld poor par dn-(]opn)(nt pspl(inlly thost ]HlPOtltl1t for long husk Dala (1( tnk(J) OJl pur l(ngtll husk pxt(llsion l)(yon([ thl tip of 1Jp (tl r husk tightmss nJ](l (11l0lJ11

dunulge lImk rXC11Rioll t1lJ1gtcl from -0) to +G7 ind(s T1J( rating of fnrWOllll dlunngp wus diHicult to dllllmill( bN~HUS( 01 thl smull 111lmbll or wCIl-fil]p(l (HIS aJHl tJH fnilul( of SOll1pound iJlfgtnmiddotds to produc( purs ~rost or tlll illhr((ls hnt llid not han N10Ugh PHIS to plrmit tin enn()lJll Ill tillg (1( ha(Il~- dnnlllg(d by till lns(ct 111(1( us ])0 signifirun t (011( In t ion JC W(PJl h usl (xtlllsioll tlnd lurworm dnmng(

In I 947 anothlr group of 314 inb1(rls I1e (sted with llsults similar to those obtuiJ1(d in 1913

From tllp dnttl 011 hoUt groups it yas (ollcludlc that i11b1((ls in h(DlSeh-(s w(n uma tisfneOlY for ill( sudy of el1rWOIJll Jesistl1l1((

4 TECInICAL BULLElIK 1160 U S DEPT OF AGRlCcLTURE

Tests of hybrids run (ontunmiddot(ntl) with the tests of inhrecls making bullup the hybrids indicated that the yalue of an inbred in breeding for resistance can be more reliably and accuratel) d(t(rmin(d b) ratillg the hybrids beenusC of their great(l yigor and more normal deyelopshylllent TIlCrefore thp pra(t1(e of rating inhreds for damage ms disshycontinuCd in 1947 and 11-bri(ls were us(d to det(rmine the preshypoteuC) of inbrCcls for CUlWOJm resistance Sing]p- doublp- 3-way and top-cross bybrids ere che~ked but almost all the data giY(l1 here were based 011 sing]p-crosio hybrids

EVALUATION OF INBREDS IN HYBRID COMBINATIONS

)fallY inbrCCls pre rated for J(sisltllc( to 1he (orn eUlworm in the 1(sts of h)7brids ill Mississippi Alnhmna and Louisinnn from 1943 to 1951 Before an 1n1)1((1 was ginn t (hfinite lating it was 1esteCt in (ombinMioll ~-~ih 01hel illlJJ(ds ill at Ittlst G ](plienlions in 2 or mol( loeations Theldon although tlHlP has b((ll SOJllP Yaliation in bull the in1(l1si1)- of the infcstMion the possihilityof (JTor in rating bns hNIl lec1u((d to ~ minimum AJthougb most inb(ds -(J( mtpc1 Oll th(ir (tl(tiOllS in singhmiddot-ClosS (om1gtin[llions doublt-(ross hybrids wJp fllso ObSP1Y(d (w~n though it WtlS dif1icult to tmce the infiu(ncp of allY 1 illhrecl dlPlP as l1lt111- as 4 inbrerls W(I( iny01(lt1

The datn for tilt inhnds lms((l 011 th(ir JHdoJmnI1(e in 1I1)1id comhinntiolls hnyl h(el) n11gtitraIih- diyickd into fOllr IlSistmle( ([LLCgories whi(1I fire d(s(1ilwd as ollows

RIIIt mlafllll evlllJiSrWfII ~ 1mOllnt uf Ralisrllwe lta(YOffl ill curs dUflWfU to Ctlf-

II ighl~ lPltbtaut Loll Kli~ht R(middotistanL ___ [oc1(ralp Klil-hl IntplnHdillte Jocllnlt IodprtllP KlIscPptilJlp High ~(YLrp

Th( following iul)l(ds hUT( 1gt((11 dnssiJiltd [l((ordillg to th(se lCsislanc( categori(s

Resista1lce caltjyory Highly IPSistllnt

hitp __ _ Ydlow

llcsistllnt bullWhitl _ F~ 14 Cl~205 CE24i (11 HEn] LSi LHj Jp30fl Ip31 Jp)35 TIOl

YlUOW __ FR F44 fpl Ip410 Ip42(i III tlllIlpdiate

Whitc __ _ GT~1 UT5 12-2 LlO L25 lA4 LflO Ul1 [p305 [p3J1 xc) XCH xCi XC45 )Ci4 XC75 R30 1-01[ U121 ]])3~R 113485

CLi 15 Fi CEaR GT1Gfll GTJGDIJ GT17) W4D Kb50 K Y5~7 KY~ L 101 L510 L515 1578 [p40~ [p4]2 [p4J4 ip428 XCi XC13 XCS~ XCS3 0-18 1204

KU(pr)( iblr h ittmiddot CGG CU3 H-21 H-22 JI- J[20~ KH K55 KG4

KI~2 KI]3 Ky27 K~4[) Ky5S KySH Kyll4 L13 124 125 102 LSG LI03 1021A fo~2 [p~Ol [ p303 1 pa07 1 p315 Ip317 [ pal fI XC3f1 XCH H7 HJ I lUi R23 110 113 114 118 161 TR3 185 T10) Ill] Tll3 fIlii Ili5A 33-1 G 5340 5370 53SfI 54H 5437

bull

bull

bull By W A Douglas entomologist Entomologt Research Branch and R C

Eckhordt agronomist Field Crops Research Branch A9ricultural Research Service

United States Department of Agriculture in cooperation with the Mississippi Agricultural Experiment Station

TIllt COlll lntorlll (lfdiothi8 ((1 (Boddir)) i~ OM of IIH most titsl rud iyt insret pests of (0111 P~I((il111- ill t h( Sou lllllII St it(S Wl11l( it ~(Ii()usl- ciul1ltLps hoth ltI(llt tlild SWllt (011 lnIY par FOl pXllmpl( gJ P(((llt of IIll (flIS (1( inf(sllci 011 llll aylI[l~( ill 2 wiilpl- llsltd YUlilti(s of OIJlII-polLiIlHttd e1lnl (0111 durillg ] 94)-5] at Stnlaquo (olhgp ~Jis Tlw nYlIng nllmblt1 of k(lnll5 dtstloyed P(l (tU ns 26 Bused 011 til( Stntl n-(ln~( yitld of 20 hushpls Jll lVle OWl illt plliod this loss nPPloxinHlt(d ]250000 huhll 101 till 2l~G()O() 1[(1(5 of (0111 glowJI Hnnunll 101 1(((1 ill ~li~issippi The loss of Slpt (0111 glO1l ill th( Slalt fol tlllt (ommllCiaL malkpt in 1948 was ptimntld ui nhout (lll(-lhild of Lilt (rop OJ nbout nlnilldl((l dolLals 1)(1 n(I(

bull In additiOIl to tl]( nrnOlllll of gmin ndllnHy CntllI b til( ltillworm

danUl~lltl ullas nlId Im(J~(IH( holls marip h til( llllnll ](1-l 1hl PH IS tH((ssihh to ltIi1ltns( olgnllisms th( Ii(( -l(jl (ilitllphilu olya (L)) nlld ntlHJ grain ins(d and liuhlr to dnmtl~( b hinls unci w(nlh(Jing (Jig 1) Til( N1Iorm also illjllJ(S (Olll foliagc nnd ttLSs(ls

In n (OOP(JHlin cOlll-impJonm(llt progrnm h- thl l~llitld Stn((s Dl]Jilrtll1ltllt or gricultul( and tl)( ~Jississ[ppi grinrilulllL ExpcrishyJllellt St nlion studi(middots (1( umkltnl(n from 1942 to 195] to d((((nsp lossls C1HISld by (iU-Olm dnlllngl to corn Tilis -or (ollsisld of brpPcling dlnt (0111 hyhrids l(sisltlnt to (lU-Orm )njur- in(hlltiing th(~ pYtlluntiol1 of [lIbnds ilnd s[ngilt- nnci doub]( (TOSS i1dnmiddotids for (Ul01lll

rcsistunc( It nIso (II tnil(d th( isolntion nnd imp1On1lll II ( or rlsisshytnmiddotnt gt[m plnsm llnd its tmllsfpltIH( to (omllulCinl hyhrids hieh offprpd an idrnJ solutioll of th( (uwonn probleUl u- in(lPHSpd -[pM ohtnillPd with ltHlToIUl-resistant hybrids -ould profit thtgt ])10shydu(([ sinep titt [osl nlUld hl no gllntpl for gro-ing rlsislnnt slrnins than Slls(pptibiltmiddot 01(5

1 HubmiUlcl for puigtJiclllioll Aug-ust 27 HJ5U

1

bull

2 TECH~ICAL ]3rLLETl~ 1160 r S DEPT OF AGIU(rLTT~HE

bull

Frm 1 Ear (II Cllrll dmllwd fy tl (lIrll 11111111 th riemiddot (Id ami djj-a llfiall (Jf ilHdlllill hll l pcotf(gt1 11111

REVIEV OF LITERATURE bull Tltl IpittllWC of dllIt lilt II It lO11l to clllllllllIl illfltntioll In

lirt 1Illllltlc II (ollill alld 1llllptoll If C ilt Illli 1111lt 1(llklI Iulld thut plo~llli( or Ipitlllt punllt Imd Iligb ]lInPlllngp of 1I11illfllld IHI lilt littll dallla~1 110111 Inrnu ill illfpt(lt1 pur Bhuwllnlll Biggl I lid ~lIlllillg II ill I 1-1 I (pollld thut (lllll illill(d trunlllil Itllllll1l llitlIl1l to ill~lp 1101 III tIll larlit1 litplashyt UI lnIOIIIl IIitlIl1( 1 llldild III I i1Il to I()u~ tuk lXIIllioll Paillt1 alld BIIIIlllll 1 OllltllIdld tlHlt hibk (Xt(lhioll Wh lIot tIll llll rurto I )i]( alld lllIkill (J) lit(d 1I Illlllll)( Ill ((lIlI B(1t illh(d tlmt tlIlIllit lalW()JIlI I(itall(( til hJlid 1111 abo IPjollld ttal (II ill 1(it1111 coliliJillltlioll hud ItlIIl tu)h 1(IIllI Hild t Itt t lll()l111 I(it ntH Wl) 1I0t 1I lInl roulld ill I()II~-It lIkd tluill III ll-Ji DOllglI Lit illdiltllid thll ItI~~11t alld tigttllCs of hllk lxtlllillll ollld Ilot 1)( dlIHlld(d Oil 10 plllll I (IWlt frottl (alI()tlll dtlllWgl

EXPERIMENTAL PROCEDURE III till 111(middot11101 ItllOIltl-Ilitnllt 0111 lJllllI (Iltl hIP IHIIl

ol)tnillld from illhlld ill yariou tugl or dlllolilllllt ill thl (()III- 1)(Ildillg [l1()gllP Ill thl ~()lllh(tll ~tltt Tht llllifollll (( pollso(d hy tilt ~()llthlIl1 (Olll ImpIOIpIl(lll (0111(1111(( hHYI I)((ll lxtuni1ll(1 Iot or th(1lt Inl (olitailllll siJl~I IIO of lit h((

J1t illhll(ls with thl hlt 0111 (llll III tdllitioJl Ilutn (lll llltl( IntI (otJl BpI [lIlmcls han 1llI1I oiJulillld 1I IlI I Oll Iruill ftUlll PIIml foni~1l lOllll t Ii(

10[ or till llltlllit1 IXllllill(d lws IWIIl ~I() II It t 11 or tPOI( of Ihl IXIllliJll(llt tlltiolb ill Iiiippi lIumiddotnlly tIll 111111 Iatiull It ~(nl( (oll(~( nnd th( ])Itl 15tllllt ~1lti()llIt ~lIlJ1lill( Tit lnlh mH t (rilll 1 ttsl (I at 11 011 ~JlliJlg 11 lid n t ~t alt ( ollpgl 0 I ~t IIlll ill I COIJl has also htPll tlHU((1 It fip otllll tXPliJIl(llt tatiolb ill tIlt ~tH[( as (11 as Oil (IIt1 dlltH plllliatioll lwkll til tht InshyIHlllHl and Louiiullt gli(tlltlllul EqHlillllnt ~IHtioll It f1()l1 llltllly of tIll I t(-llltt II Iillf inglemiddot (101 101 ll()tlIl tlltlil

Ilalie Jllllldl~ ill jlalflIlh~I~ ]Ir In Litlllllll (itd p la

bull

3

bull

bull

bull

bull

DENT CORN INBREDS AND HYBRIDS RESISTANT TO CORN EARWORM

Oe11erI111- the corn was plun ted in 40- b- 40-i11(h hills in 2- by 10shyhill plots thuUltcl to 2 or 3 stalks per hill iUlcl replicated a to 6 times at eaeh of s(verul loeations En tries were usunlly grouped into (arly) midsenson and late strains The corn ltceiyed nmple fertilizer It nlS cultiyatecl in the lIsuulmnnl1er amI alloncl to open-pollinab

Ilesistuute of eorn en1S to fC((lil1g b- the ean-orm wns one of the rrit0rin lIs((l in sel(ding inhreds for furtlur l1S( in the br(eding program 11 t State COlJ0gC In brCds pnpotCll t for eaJwOlln r(Sistllll(l were 1I5((1 or they were closs(d with illhrecls superior jll other charactershyisti(s but poor in earworm ](sistnncl From sueh cross(s inhrecls WNt selected for (nlworm resistanC( as well us for good yield lodging ]rsistaJl( rnd otlWl desimhl agronomic ehnractLJs

In tll(s( shldies data pre J(cord(d for th lIsual agronomic charshylHkrs and for husk lxknsion heyond the tip of thl tiU) husk tigh t shyness ilm1 u)(et (lmnag( to tht (nrs ltCle t]i( iuflstatiOH wns seypll (n011gh hud dmnngp on young (Olll wns somCtim(s Jlotpd Datn qre also 1((o1cl((l 011 oyiposj(ion hy thc (arwoJm moths on the silks ill plCI((l trsts

111p eOln jn PHell plot nls Juunstlltl SllHlrntply nmI rnell (HI middotus rntrltl tiS follos for rHlWOIlIl (lnmugl

1JlCr of kernel

Jce~ or rill maue dcsrollcd RlllillU pc III lrulioll prr car

(11 o Il I J 2 II L 3middot1 L 15 5 130

1 0 ilffalioll

Thl HT(rage dt1l1U1W Ill tin~ Jlll (11(11 plot as (ld(IJl1iJ1pd l)y multishyplying tlH ruting h- the l1uml)(1 or (urs ginn thn rating ndding the plocluCts nJl(l c[iyjcling b the otni mnnlwl of ears From the uY(rng( nl (ing 101 (Hell plot lIns ohtuul(ltl ntlt a (nlgp for the entry ill the tpst TIll ]wlePJltnglt ofinfcst(d etlrs WHS n]so eukuinfc(L

EYALUATION OF INBREDS III 1n4~ n group of 4()) iniJncls W(I( studi(cl ~Iost of th(lll crc

]lot vigorous and (onsNIII(llI- Itld poor par dn-(]opn)(nt pspl(inlly thost ]HlPOtltl1t for long husk Dala (1( tnk(J) OJl pur l(ngtll husk pxt(llsion l)(yon([ thl tip of 1Jp (tl r husk tightmss nJ](l (11l0lJ11

dunulge lImk rXC11Rioll t1lJ1gtcl from -0) to +G7 ind(s T1J( rating of fnrWOllll dlunngp wus diHicult to dllllmill( bN~HUS( 01 thl smull 111lmbll or wCIl-fil]p(l (HIS aJHl tJH fnilul( of SOll1pound iJlfgtnmiddotds to produc( purs ~rost or tlll illhr((ls hnt llid not han N10Ugh PHIS to plrmit tin enn()lJll Ill tillg (1( ha(Il~- dnnlllg(d by till lns(ct 111(1( us ])0 signifirun t (011( In t ion JC W(PJl h usl (xtlllsioll tlnd lurworm dnmng(

In I 947 anothlr group of 314 inb1(rls I1e (sted with llsults similar to those obtuiJ1(d in 1913

From tllp dnttl 011 hoUt groups it yas (ollcludlc that i11b1((ls in h(DlSeh-(s w(n uma tisfneOlY for ill( sudy of el1rWOIJll Jesistl1l1((

4 TECInICAL BULLElIK 1160 U S DEPT OF AGRlCcLTURE

Tests of hybrids run (ontunmiddot(ntl) with the tests of inhrecls making bullup the hybrids indicated that the yalue of an inbred in breeding for resistance can be more reliably and accuratel) d(t(rmin(d b) ratillg the hybrids beenusC of their great(l yigor and more normal deyelopshylllent TIlCrefore thp pra(t1(e of rating inhreds for damage ms disshycontinuCd in 1947 and 11-bri(ls were us(d to det(rmine the preshypoteuC) of inbrCcls for CUlWOJm resistance Sing]p- doublp- 3-way and top-cross bybrids ere che~ked but almost all the data giY(l1 here were based 011 sing]p-crosio hybrids

EVALUATION OF INBREDS IN HYBRID COMBINATIONS

)fallY inbrCCls pre rated for J(sisltllc( to 1he (orn eUlworm in the 1(sts of h)7brids ill Mississippi Alnhmna and Louisinnn from 1943 to 1951 Before an 1n1)1((1 was ginn t (hfinite lating it was 1esteCt in (ombinMioll ~-~ih 01hel illlJJ(ds ill at Ittlst G ](plienlions in 2 or mol( loeations Theldon although tlHlP has b((ll SOJllP Yaliation in bull the in1(l1si1)- of the infcstMion the possihilityof (JTor in rating bns hNIl lec1u((d to ~ minimum AJthougb most inb(ds -(J( mtpc1 Oll th(ir (tl(tiOllS in singhmiddot-ClosS (om1gtin[llions doublt-(ross hybrids wJp fllso ObSP1Y(d (w~n though it WtlS dif1icult to tmce the infiu(ncp of allY 1 illhrecl dlPlP as l1lt111- as 4 inbrerls W(I( iny01(lt1

The datn for tilt inhnds lms((l 011 th(ir JHdoJmnI1(e in 1I1)1id comhinntiolls hnyl h(el) n11gtitraIih- diyickd into fOllr IlSistmle( ([LLCgories whi(1I fire d(s(1ilwd as ollows

RIIIt mlafllll evlllJiSrWfII ~ 1mOllnt uf Ralisrllwe lta(YOffl ill curs dUflWfU to Ctlf-

II ighl~ lPltbtaut Loll Kli~ht R(middotistanL ___ [oc1(ralp Klil-hl IntplnHdillte Jocllnlt IodprtllP KlIscPptilJlp High ~(YLrp

Th( following iul)l(ds hUT( 1gt((11 dnssiJiltd [l((ordillg to th(se lCsislanc( categori(s

Resista1lce caltjyory Highly IPSistllnt

hitp __ _ Ydlow

llcsistllnt bullWhitl _ F~ 14 Cl~205 CE24i (11 HEn] LSi LHj Jp30fl Ip31 Jp)35 TIOl

YlUOW __ FR F44 fpl Ip410 Ip42(i III tlllIlpdiate

Whitc __ _ GT~1 UT5 12-2 LlO L25 lA4 LflO Ul1 [p305 [p3J1 xc) XCH xCi XC45 )Ci4 XC75 R30 1-01[ U121 ]])3~R 113485

CLi 15 Fi CEaR GT1Gfll GTJGDIJ GT17) W4D Kb50 K Y5~7 KY~ L 101 L510 L515 1578 [p40~ [p4]2 [p4J4 ip428 XCi XC13 XCS~ XCS3 0-18 1204

KU(pr)( iblr h ittmiddot CGG CU3 H-21 H-22 JI- J[20~ KH K55 KG4

KI~2 KI]3 Ky27 K~4[) Ky5S KySH Kyll4 L13 124 125 102 LSG LI03 1021A fo~2 [p~Ol [ p303 1 pa07 1 p315 Ip317 [ pal fI XC3f1 XCH H7 HJ I lUi R23 110 113 114 118 161 TR3 185 T10) Ill] Tll3 fIlii Ili5A 33-1 G 5340 5370 53SfI 54H 5437

bull

2 TECH~ICAL ]3rLLETl~ 1160 r S DEPT OF AGIU(rLTT~HE

bull

Frm 1 Ear (II Cllrll dmllwd fy tl (lIrll 11111111 th riemiddot (Id ami djj-a llfiall (Jf ilHdlllill hll l pcotf(gt1 11111

REVIEV OF LITERATURE bull Tltl IpittllWC of dllIt lilt II It lO11l to clllllllllIl illfltntioll In

lirt 1Illllltlc II (ollill alld 1llllptoll If C ilt Illli 1111lt 1(llklI Iulld thut plo~llli( or Ipitlllt punllt Imd Iligb ]lInPlllngp of 1I11illfllld IHI lilt littll dallla~1 110111 Inrnu ill illfpt(lt1 pur Bhuwllnlll Biggl I lid ~lIlllillg II ill I 1-1 I (pollld thut (lllll illill(d trunlllil Itllllll1l llitlIl1l to ill~lp 1101 III tIll larlit1 litplashyt UI lnIOIIIl IIitlIl1( 1 llldild III I i1Il to I()u~ tuk lXIIllioll Paillt1 alld BIIIIlllll 1 OllltllIdld tlHlt hibk (Xt(lhioll Wh lIot tIll llll rurto I )i]( alld lllIkill (J) lit(d 1I Illlllll)( Ill ((lIlI B(1t illh(d tlmt tlIlIllit lalW()JIlI I(itall(( til hJlid 1111 abo IPjollld ttal (II ill 1(it1111 coliliJillltlioll hud ItlIIl tu)h 1(IIllI Hild t Itt t lll()l111 I(it ntH Wl) 1I0t 1I lInl roulld ill I()II~-It lIkd tluill III ll-Ji DOllglI Lit illdiltllid thll ItI~~11t alld tigttllCs of hllk lxtlllillll ollld Ilot 1)( dlIHlld(d Oil 10 plllll I (IWlt frottl (alI()tlll dtlllWgl

EXPERIMENTAL PROCEDURE III till 111(middot11101 ItllOIltl-Ilitnllt 0111 lJllllI (Iltl hIP IHIIl

ol)tnillld from illhlld ill yariou tugl or dlllolilllllt ill thl (()III- 1)(Ildillg [l1()gllP Ill thl ~()lllh(tll ~tltt Tht llllifollll (( pollso(d hy tilt ~()llthlIl1 (Olll ImpIOIpIl(lll (0111(1111(( hHYI I)((ll lxtuni1ll(1 Iot or th(1lt Inl (olitailllll siJl~I IIO of lit h((

J1t illhll(ls with thl hlt 0111 (llll III tdllitioJl Ilutn (lll llltl( IntI (otJl BpI [lIlmcls han 1llI1I oiJulillld 1I IlI I Oll Iruill ftUlll PIIml foni~1l lOllll t Ii(

10[ or till llltlllit1 IXllllill(d lws IWIIl ~I() II It t 11 or tPOI( of Ihl IXIllliJll(llt tlltiolb ill Iiiippi lIumiddotnlly tIll 111111 Iatiull It ~(nl( (oll(~( nnd th( ])Itl 15tllllt ~1lti()llIt ~lIlJ1lill( Tit lnlh mH t (rilll 1 ttsl (I at 11 011 ~JlliJlg 11 lid n t ~t alt ( ollpgl 0 I ~t IIlll ill I COIJl has also htPll tlHU((1 It fip otllll tXPliJIl(llt tatiolb ill tIlt ~tH[( as (11 as Oil (IIt1 dlltH plllliatioll lwkll til tht InshyIHlllHl and Louiiullt gli(tlltlllul EqHlillllnt ~IHtioll It f1()l1 llltllly of tIll I t(-llltt II Iillf inglemiddot (101 101 ll()tlIl tlltlil

Ilalie Jllllldl~ ill jlalflIlh~I~ ]Ir In Litlllllll (itd p la

bull

3

bull

bull

bull

bull

DENT CORN INBREDS AND HYBRIDS RESISTANT TO CORN EARWORM

Oe11erI111- the corn was plun ted in 40- b- 40-i11(h hills in 2- by 10shyhill plots thuUltcl to 2 or 3 stalks per hill iUlcl replicated a to 6 times at eaeh of s(verul loeations En tries were usunlly grouped into (arly) midsenson and late strains The corn ltceiyed nmple fertilizer It nlS cultiyatecl in the lIsuulmnnl1er amI alloncl to open-pollinab

Ilesistuute of eorn en1S to fC((lil1g b- the ean-orm wns one of the rrit0rin lIs((l in sel(ding inhreds for furtlur l1S( in the br(eding program 11 t State COlJ0gC In brCds pnpotCll t for eaJwOlln r(Sistllll(l were 1I5((1 or they were closs(d with illhrecls superior jll other charactershyisti(s but poor in earworm ](sistnncl From sueh cross(s inhrecls WNt selected for (nlworm resistanC( as well us for good yield lodging ]rsistaJl( rnd otlWl desimhl agronomic ehnractLJs

In tll(s( shldies data pre J(cord(d for th lIsual agronomic charshylHkrs and for husk lxknsion heyond the tip of thl tiU) husk tigh t shyness ilm1 u)(et (lmnag( to tht (nrs ltCle t]i( iuflstatiOH wns seypll (n011gh hud dmnngp on young (Olll wns somCtim(s Jlotpd Datn qre also 1((o1cl((l 011 oyiposj(ion hy thc (arwoJm moths on the silks ill plCI((l trsts

111p eOln jn PHell plot nls Juunstlltl SllHlrntply nmI rnell (HI middotus rntrltl tiS follos for rHlWOIlIl (lnmugl

1JlCr of kernel

Jce~ or rill maue dcsrollcd RlllillU pc III lrulioll prr car

(11 o Il I J 2 II L 3middot1 L 15 5 130

1 0 ilffalioll

Thl HT(rage dt1l1U1W Ill tin~ Jlll (11(11 plot as (ld(IJl1iJ1pd l)y multishyplying tlH ruting h- the l1uml)(1 or (urs ginn thn rating ndding the plocluCts nJl(l c[iyjcling b the otni mnnlwl of ears From the uY(rng( nl (ing 101 (Hell plot lIns ohtuul(ltl ntlt a (nlgp for the entry ill the tpst TIll ]wlePJltnglt ofinfcst(d etlrs WHS n]so eukuinfc(L

EYALUATION OF INBREDS III 1n4~ n group of 4()) iniJncls W(I( studi(cl ~Iost of th(lll crc

]lot vigorous and (onsNIII(llI- Itld poor par dn-(]opn)(nt pspl(inlly thost ]HlPOtltl1t for long husk Dala (1( tnk(J) OJl pur l(ngtll husk pxt(llsion l)(yon([ thl tip of 1Jp (tl r husk tightmss nJ](l (11l0lJ11

dunulge lImk rXC11Rioll t1lJ1gtcl from -0) to +G7 ind(s T1J( rating of fnrWOllll dlunngp wus diHicult to dllllmill( bN~HUS( 01 thl smull 111lmbll or wCIl-fil]p(l (HIS aJHl tJH fnilul( of SOll1pound iJlfgtnmiddotds to produc( purs ~rost or tlll illhr((ls hnt llid not han N10Ugh PHIS to plrmit tin enn()lJll Ill tillg (1( ha(Il~- dnnlllg(d by till lns(ct 111(1( us ])0 signifirun t (011( In t ion JC W(PJl h usl (xtlllsioll tlnd lurworm dnmng(

In I 947 anothlr group of 314 inb1(rls I1e (sted with llsults similar to those obtuiJ1(d in 1913

From tllp dnttl 011 hoUt groups it yas (ollcludlc that i11b1((ls in h(DlSeh-(s w(n uma tisfneOlY for ill( sudy of el1rWOIJll Jesistl1l1((

4 TECInICAL BULLElIK 1160 U S DEPT OF AGRlCcLTURE

Tests of hybrids run (ontunmiddot(ntl) with the tests of inhrecls making bullup the hybrids indicated that the yalue of an inbred in breeding for resistance can be more reliably and accuratel) d(t(rmin(d b) ratillg the hybrids beenusC of their great(l yigor and more normal deyelopshylllent TIlCrefore thp pra(t1(e of rating inhreds for damage ms disshycontinuCd in 1947 and 11-bri(ls were us(d to det(rmine the preshypoteuC) of inbrCcls for CUlWOJm resistance Sing]p- doublp- 3-way and top-cross bybrids ere che~ked but almost all the data giY(l1 here were based 011 sing]p-crosio hybrids

EVALUATION OF INBREDS IN HYBRID COMBINATIONS

)fallY inbrCCls pre rated for J(sisltllc( to 1he (orn eUlworm in the 1(sts of h)7brids ill Mississippi Alnhmna and Louisinnn from 1943 to 1951 Before an 1n1)1((1 was ginn t (hfinite lating it was 1esteCt in (ombinMioll ~-~ih 01hel illlJJ(ds ill at Ittlst G ](plienlions in 2 or mol( loeations Theldon although tlHlP has b((ll SOJllP Yaliation in bull the in1(l1si1)- of the infcstMion the possihilityof (JTor in rating bns hNIl lec1u((d to ~ minimum AJthougb most inb(ds -(J( mtpc1 Oll th(ir (tl(tiOllS in singhmiddot-ClosS (om1gtin[llions doublt-(ross hybrids wJp fllso ObSP1Y(d (w~n though it WtlS dif1icult to tmce the infiu(ncp of allY 1 illhrecl dlPlP as l1lt111- as 4 inbrerls W(I( iny01(lt1

The datn for tilt inhnds lms((l 011 th(ir JHdoJmnI1(e in 1I1)1id comhinntiolls hnyl h(el) n11gtitraIih- diyickd into fOllr IlSistmle( ([LLCgories whi(1I fire d(s(1ilwd as ollows

RIIIt mlafllll evlllJiSrWfII ~ 1mOllnt uf Ralisrllwe lta(YOffl ill curs dUflWfU to Ctlf-

II ighl~ lPltbtaut Loll Kli~ht R(middotistanL ___ [oc1(ralp Klil-hl IntplnHdillte Jocllnlt IodprtllP KlIscPptilJlp High ~(YLrp

Th( following iul)l(ds hUT( 1gt((11 dnssiJiltd [l((ordillg to th(se lCsislanc( categori(s

Resista1lce caltjyory Highly IPSistllnt

hitp __ _ Ydlow

llcsistllnt bullWhitl _ F~ 14 Cl~205 CE24i (11 HEn] LSi LHj Jp30fl Ip31 Jp)35 TIOl

YlUOW __ FR F44 fpl Ip410 Ip42(i III tlllIlpdiate

Whitc __ _ GT~1 UT5 12-2 LlO L25 lA4 LflO Ul1 [p305 [p3J1 xc) XCH xCi XC45 )Ci4 XC75 R30 1-01[ U121 ]])3~R 113485

CLi 15 Fi CEaR GT1Gfll GTJGDIJ GT17) W4D Kb50 K Y5~7 KY~ L 101 L510 L515 1578 [p40~ [p4]2 [p4J4 ip428 XCi XC13 XCS~ XCS3 0-18 1204

KU(pr)( iblr h ittmiddot CGG CU3 H-21 H-22 JI- J[20~ KH K55 KG4

KI~2 KI]3 Ky27 K~4[) Ky5S KySH Kyll4 L13 124 125 102 LSG LI03 1021A fo~2 [p~Ol [ p303 1 pa07 1 p315 Ip317 [ pal fI XC3f1 XCH H7 HJ I lUi R23 110 113 114 118 161 TR3 185 T10) Ill] Tll3 fIlii Ili5A 33-1 G 5340 5370 53SfI 54H 5437

bull

3

bull

bull

bull

bull

DENT CORN INBREDS AND HYBRIDS RESISTANT TO CORN EARWORM

Oe11erI111- the corn was plun ted in 40- b- 40-i11(h hills in 2- by 10shyhill plots thuUltcl to 2 or 3 stalks per hill iUlcl replicated a to 6 times at eaeh of s(verul loeations En tries were usunlly grouped into (arly) midsenson and late strains The corn ltceiyed nmple fertilizer It nlS cultiyatecl in the lIsuulmnnl1er amI alloncl to open-pollinab

Ilesistuute of eorn en1S to fC((lil1g b- the ean-orm wns one of the rrit0rin lIs((l in sel(ding inhreds for furtlur l1S( in the br(eding program 11 t State COlJ0gC In brCds pnpotCll t for eaJwOlln r(Sistllll(l were 1I5((1 or they were closs(d with illhrecls superior jll other charactershyisti(s but poor in earworm ](sistnncl From sueh cross(s inhrecls WNt selected for (nlworm resistanC( as well us for good yield lodging ]rsistaJl( rnd otlWl desimhl agronomic ehnractLJs

In tll(s( shldies data pre J(cord(d for th lIsual agronomic charshylHkrs and for husk lxknsion heyond the tip of thl tiU) husk tigh t shyness ilm1 u)(et (lmnag( to tht (nrs ltCle t]i( iuflstatiOH wns seypll (n011gh hud dmnngp on young (Olll wns somCtim(s Jlotpd Datn qre also 1((o1cl((l 011 oyiposj(ion hy thc (arwoJm moths on the silks ill plCI((l trsts

111p eOln jn PHell plot nls Juunstlltl SllHlrntply nmI rnell (HI middotus rntrltl tiS follos for rHlWOIlIl (lnmugl

1JlCr of kernel

Jce~ or rill maue dcsrollcd RlllillU pc III lrulioll prr car

(11 o Il I J 2 II L 3middot1 L 15 5 130

1 0 ilffalioll

Thl HT(rage dt1l1U1W Ill tin~ Jlll (11(11 plot as (ld(IJl1iJ1pd l)y multishyplying tlH ruting h- the l1uml)(1 or (urs ginn thn rating ndding the plocluCts nJl(l c[iyjcling b the otni mnnlwl of ears From the uY(rng( nl (ing 101 (Hell plot lIns ohtuul(ltl ntlt a (nlgp for the entry ill the tpst TIll ]wlePJltnglt ofinfcst(d etlrs WHS n]so eukuinfc(L

EYALUATION OF INBREDS III 1n4~ n group of 4()) iniJncls W(I( studi(cl ~Iost of th(lll crc

]lot vigorous and (onsNIII(llI- Itld poor par dn-(]opn)(nt pspl(inlly thost ]HlPOtltl1t for long husk Dala (1( tnk(J) OJl pur l(ngtll husk pxt(llsion l)(yon([ thl tip of 1Jp (tl r husk tightmss nJ](l (11l0lJ11

dunulge lImk rXC11Rioll t1lJ1gtcl from -0) to +G7 ind(s T1J( rating of fnrWOllll dlunngp wus diHicult to dllllmill( bN~HUS( 01 thl smull 111lmbll or wCIl-fil]p(l (HIS aJHl tJH fnilul( of SOll1pound iJlfgtnmiddotds to produc( purs ~rost or tlll illhr((ls hnt llid not han N10Ugh PHIS to plrmit tin enn()lJll Ill tillg (1( ha(Il~- dnnlllg(d by till lns(ct 111(1( us ])0 signifirun t (011( In t ion JC W(PJl h usl (xtlllsioll tlnd lurworm dnmng(

In I 947 anothlr group of 314 inb1(rls I1e (sted with llsults similar to those obtuiJ1(d in 1913

From tllp dnttl 011 hoUt groups it yas (ollcludlc that i11b1((ls in h(DlSeh-(s w(n uma tisfneOlY for ill( sudy of el1rWOIJll Jesistl1l1((

4 TECInICAL BULLElIK 1160 U S DEPT OF AGRlCcLTURE

Tests of hybrids run (ontunmiddot(ntl) with the tests of inhrecls making bullup the hybrids indicated that the yalue of an inbred in breeding for resistance can be more reliably and accuratel) d(t(rmin(d b) ratillg the hybrids beenusC of their great(l yigor and more normal deyelopshylllent TIlCrefore thp pra(t1(e of rating inhreds for damage ms disshycontinuCd in 1947 and 11-bri(ls were us(d to det(rmine the preshypoteuC) of inbrCcls for CUlWOJm resistance Sing]p- doublp- 3-way and top-cross bybrids ere che~ked but almost all the data giY(l1 here were based 011 sing]p-crosio hybrids

EVALUATION OF INBREDS IN HYBRID COMBINATIONS

)fallY inbrCCls pre rated for J(sisltllc( to 1he (orn eUlworm in the 1(sts of h)7brids ill Mississippi Alnhmna and Louisinnn from 1943 to 1951 Before an 1n1)1((1 was ginn t (hfinite lating it was 1esteCt in (ombinMioll ~-~ih 01hel illlJJ(ds ill at Ittlst G ](plienlions in 2 or mol( loeations Theldon although tlHlP has b((ll SOJllP Yaliation in bull the in1(l1si1)- of the infcstMion the possihilityof (JTor in rating bns hNIl lec1u((d to ~ minimum AJthougb most inb(ds -(J( mtpc1 Oll th(ir (tl(tiOllS in singhmiddot-ClosS (om1gtin[llions doublt-(ross hybrids wJp fllso ObSP1Y(d (w~n though it WtlS dif1icult to tmce the infiu(ncp of allY 1 illhrecl dlPlP as l1lt111- as 4 inbrerls W(I( iny01(lt1

The datn for tilt inhnds lms((l 011 th(ir JHdoJmnI1(e in 1I1)1id comhinntiolls hnyl h(el) n11gtitraIih- diyickd into fOllr IlSistmle( ([LLCgories whi(1I fire d(s(1ilwd as ollows

RIIIt mlafllll evlllJiSrWfII ~ 1mOllnt uf Ralisrllwe lta(YOffl ill curs dUflWfU to Ctlf-

II ighl~ lPltbtaut Loll Kli~ht R(middotistanL ___ [oc1(ralp Klil-hl IntplnHdillte Jocllnlt IodprtllP KlIscPptilJlp High ~(YLrp

Th( following iul)l(ds hUT( 1gt((11 dnssiJiltd [l((ordillg to th(se lCsislanc( categori(s

Resista1lce caltjyory Highly IPSistllnt

hitp __ _ Ydlow

llcsistllnt bullWhitl _ F~ 14 Cl~205 CE24i (11 HEn] LSi LHj Jp30fl Ip31 Jp)35 TIOl

YlUOW __ FR F44 fpl Ip410 Ip42(i III tlllIlpdiate

Whitc __ _ GT~1 UT5 12-2 LlO L25 lA4 LflO Ul1 [p305 [p3J1 xc) XCH xCi XC45 )Ci4 XC75 R30 1-01[ U121 ]])3~R 113485

CLi 15 Fi CEaR GT1Gfll GTJGDIJ GT17) W4D Kb50 K Y5~7 KY~ L 101 L510 L515 1578 [p40~ [p4]2 [p4J4 ip428 XCi XC13 XCS~ XCS3 0-18 1204

KU(pr)( iblr h ittmiddot CGG CU3 H-21 H-22 JI- J[20~ KH K55 KG4

KI~2 KI]3 Ky27 K~4[) Ky5S KySH Kyll4 L13 124 125 102 LSG LI03 1021A fo~2 [p~Ol [ p303 1 pa07 1 p315 Ip317 [ pal fI XC3f1 XCH H7 HJ I lUi R23 110 113 114 118 161 TR3 185 T10) Ill] Tll3 fIlii Ili5A 33-1 G 5340 5370 53SfI 54H 5437

bull

4 TECInICAL BULLElIK 1160 U S DEPT OF AGRlCcLTURE

Tests of hybrids run (ontunmiddot(ntl) with the tests of inhrecls making bullup the hybrids indicated that the yalue of an inbred in breeding for resistance can be more reliably and accuratel) d(t(rmin(d b) ratillg the hybrids beenusC of their great(l yigor and more normal deyelopshylllent TIlCrefore thp pra(t1(e of rating inhreds for damage ms disshycontinuCd in 1947 and 11-bri(ls were us(d to det(rmine the preshypoteuC) of inbrCcls for CUlWOJm resistance Sing]p- doublp- 3-way and top-cross bybrids ere che~ked but almost all the data giY(l1 here were based 011 sing]p-crosio hybrids

EVALUATION OF INBREDS IN HYBRID COMBINATIONS

)fallY inbrCCls pre rated for J(sisltllc( to 1he (orn eUlworm in the 1(sts of h)7brids ill Mississippi Alnhmna and Louisinnn from 1943 to 1951 Before an 1n1)1((1 was ginn t (hfinite lating it was 1esteCt in (ombinMioll ~-~ih 01hel illlJJ(ds ill at Ittlst G ](plienlions in 2 or mol( loeations Theldon although tlHlP has b((ll SOJllP Yaliation in bull the in1(l1si1)- of the infcstMion the possihilityof (JTor in rating bns hNIl lec1u((d to ~ minimum AJthougb most inb(ds -(J( mtpc1 Oll th(ir (tl(tiOllS in singhmiddot-ClosS (om1gtin[llions doublt-(ross hybrids wJp fllso ObSP1Y(d (w~n though it WtlS dif1icult to tmce the infiu(ncp of allY 1 illhrecl dlPlP as l1lt111- as 4 inbrerls W(I( iny01(lt1

The datn for tilt inhnds lms((l 011 th(ir JHdoJmnI1(e in 1I1)1id comhinntiolls hnyl h(el) n11gtitraIih- diyickd into fOllr IlSistmle( ([LLCgories whi(1I fire d(s(1ilwd as ollows

RIIIt mlafllll evlllJiSrWfII ~ 1mOllnt uf Ralisrllwe lta(YOffl ill curs dUflWfU to Ctlf-

II ighl~ lPltbtaut Loll Kli~ht R(middotistanL ___ [oc1(ralp Klil-hl IntplnHdillte Jocllnlt IodprtllP KlIscPptilJlp High ~(YLrp

Th( following iul)l(ds hUT( 1gt((11 dnssiJiltd [l((ordillg to th(se lCsislanc( categori(s

Resista1lce caltjyory Highly IPSistllnt

hitp __ _ Ydlow

llcsistllnt bullWhitl _ F~ 14 Cl~205 CE24i (11 HEn] LSi LHj Jp30fl Ip31 Jp)35 TIOl

YlUOW __ FR F44 fpl Ip410 Ip42(i III tlllIlpdiate

Whitc __ _ GT~1 UT5 12-2 LlO L25 lA4 LflO Ul1 [p305 [p3J1 xc) XCH xCi XC45 )Ci4 XC75 R30 1-01[ U121 ]])3~R 113485

CLi 15 Fi CEaR GT1Gfll GTJGDIJ GT17) W4D Kb50 K Y5~7 KY~ L 101 L510 L515 1578 [p40~ [p4]2 [p4J4 ip428 XCi XC13 XCS~ XCS3 0-18 1204

KU(pr)( iblr h ittmiddot CGG CU3 H-21 H-22 JI- J[20~ KH K55 KG4

KI~2 KI]3 Ky27 K~4[) Ky5S KySH Kyll4 L13 124 125 102 LSG LI03 1021A fo~2 [p~Ol [ p303 1 pa07 1 p315 Ip317 [ pal fI XC3f1 XCH H7 HJ I lUi R23 110 113 114 118 161 TR3 185 T10) Ill] Tll3 fIlii Ili5A 33-1 G 5340 5370 53SfI 54H 5437

bull

-----

5

bull

bull

bull

bull

DENT CORX IXBREDS AXD HYBRIDS RESISTAJT TO CORN EARWORM

Resistan~e category Inured Slisceptible-Continurd

)poundgtlIow __________ CL21 51 F6+ 0122 GT112 GT152 G1l54 14 K] 55 K201-C Li540 L548 1569 L575 L586 L587 L588 LiSO Ip412 O--H ()-14-1 0-10 c)-52 H34- H37 H40 18 1202 M28

In addition to the ]lr0(rdillg inhnmiddotds J1ltLJl- rlHrimrnLiLl and Corn BrIt inhrlds and tbosl from 01hrl sow(rs -(10 l(st((1 and discarded be(ausp of suserptihilit or ng-Ionomie reasons tJwrdOl0 thp- -P1(

not inCluckd ill this list YhPH (-aluatrd on the hf1Sis of tests -wilh sing-it (IOSS(S S011ll

illbJlds showed sweiIic (omhining ahllity for ((llWOlm ](sistarj(~p Some inhrrds nlp highly l(sistant ill c(rtaill sing-If (IOSSpS but tl)(shyw(rr much kss ](sistunt ill othrl sillg-It (rossps Till explallatiol1lluLY hp that ruIWOllll-Jtsistnnt 1n((ols uJ( dl( to n llulllhpl of gl])0S For (xump1r us sholI in inh]( ] tlH inhJ((l T204 hns Ull unlfLge dnlJUlgp rnting of ] -)] -which is low hut it has not h(PI1 (onsistlnt ill its pldolmnI1(p with othll inblrds It us HI- good with ~Jp4JO nIHl (ry VOOI with ~Jp42(j Thr nisnn(( of flninblld of this tlJe Ctlnl10t 1)( pI(dictrd on ill( result obtnilHd h- (loRsing it with al)othll inbnd of knO1l YahH On the otlH1 hand (121 CIOSSlS fll( gPIHrnlJshylownnl tlw us((ptibll (Ind o[ tl1( scull -h(I(flS ~lp410 (TOSBrS are glllllall toul(l t1l( ]tsis(nllt PIll Both (121 and ~Ip4] 0 al( g(IHlnl cltllllbillPJS

TABLE 1middot (011 (([111111II (liwwge ratillgs J (~f sillgle (I088(S Id (f 1(8isiollt 111 ill tolfluliaf Ilnd a s1l8Cepiibh ydlO1J inbl(middotd amoNf (middot(fell other ((lid 11 (Jilt( lIi1oH illbl(d~ ill t(it~ at Staff (O(f[ll 1i88 1948-)]

IllbJpd Hlsistanjmiddot )nIIJlllcdiajr -usCCpLib]p Slp4IO 1204- CI21

Ralill1 H(1ill( Halil( R(middotis( tun

-)1pJ O lHl 1 )- 1 88 fplJO OJ 203 Ip+26_ I 5~ 245 2 66

IIIpnrHdiate Kls4fL 1 40 1 30 2 57 11850 _bull 1 65 2 21 2 Sf-) lp4-12 1 14 2 03 2 If) 1])4-14 l 21 1 85 2 2 fp42lgt 1 61 1 flO ~ 51 1204bullbull 91 2 41

KlIStppt ible CI2L 203 2 41 - - - ~ - GT112 1 fll 223 ) no

(lOWls Kl27 1 61 1 64 2 68

1 -)K1s14a (- 2 06 2 R2 ) shyIp440bull 1 00 2 _n 2 78

1 i51 1 01 2 iiI

1 0 = 110 infllt at ion For (umplp(( (xplnllntiOIli(c p 3

TI10 iDblpd Cr7 is dnssifi(d in thp PIP((dillg lis as iJltltllll(diate ill susccptibilil to thr lnrworm h010115 Dickl lLlld Jpnkins (3) list(d

6 TECElJJCAL BULLETlN 1160 U S DEPT OF AGRICULTURE

it 05 (onsistrntly traJ)smitting to hybrids (ar qualiti(s thut gnT( good bull prot(c-tio)) llguinst (tt1W01111 dmlUtgp Thesp obs(nutions indicuLe tha Lthe h(uyy eurOrnl damag0 ill thp Gulf (onst Stat0s gi ns it mOr0 spy(l( test for 1P5istal1(p than in UrN1S whplP th(- Nllworlll is ]lot so iLbundant al1d that mui0lial showing )lsistalJ(0 llndpr a light infestushy[ion may not gin resistllJlel undpl fl Y(JY h(iWY illfpstation

In 1946 1110 doublp-(Joss hybrid La 1030 sllO(ltI 10sistanc( in ull ((st plots at 7 10catioHs ill ~iississippi lnd 2 ill Louisiul1u In 947 n11 possib10 (omhinatiolls of t1H inhreds thalmukt up this hyhrid Wllt t(s(ld at Stah (olIPgp (0 rletermilJP -lieh in1)1((ls contrihllltd parshyoJJl11PsisiilJlCt Till datn on tl1(s( il11gt](ds and on Ln )030 and till doublp-eloss hyhrid Dixil 17 wwd for (ompnrison art gin1l in tablP 2 1110 illh1(lt1 L503 was found to he thl most nsistnnt nnd 1501 slightly resistant bull

TABLE 2 ~ (olllearwolm ria mage ralillg8 1 II(( pII((lItag(s of (a18 pound7tfesird (~f 4 ~nbr(dg (d La 1030 as (J7)I(SSU in IlIfi 8illgh-cloSS

7J1vglllils and 4 [hI doublt-(t088 hybrid~ La 1080 and TJiril 17 71l bullte8t~ at Stale (olhg( Jfisg 194

Uj(j)1501 Li4S

Entry i Enr- ]~ar- I~ar- J~ar-worm Earl worm Ear worlll Ear OlIlt Ear

damtljl inflltNl dtllllagp infptilld danlt1ge infplttpd damagl infpINI rating ratillf rltillj rat ing

PertrIIl PC((1l1 Perrenl L501 O ii4 3H 1 ~R 7 I 34 73

L Oj GGLiiO3 O )4 30 S~ ~R Lii4S I ~S 7) iiS I so sa 15GB 1)4 7] IH 1 SI

-)()l_ S] 34 1- 1 41

IIYBHllhi bullEarorm Ear

Elltry dHln~l~p illfpl (I rating

)((1

Ln JO30 I 3S 7G Dixit 17_ OO llii

O=no infltation For (olllplpumiddot (xpllIWliun P( p 3 2 Lllst ignifiel III difrlrPIlCl at til( 3-pplc(llt 1((1 i 041

Tpn whittinhlCc]s in(ll1din~ LjO] Llld Li503 W(ln ttstld in nl possiblp sill~l( (TOSSlS nt Xnt(hlz liss ill 1948 Thl datn ar0 shown ill tnbll a The 111gll ltSistfLllcP of 1501 llld L501 is dearly d(I1lonsin)icd Almost (VtIT cross with L50 or L501 J1tul a 10nI laiworm dLmnge rnting thnJ] (Ioss(s with tLllyof till other inbrpds

bull

l

bull bull bull bull 1-3

t l1 ~

() o ~ y

IAHJJI~ 3-Con e(rWOi1 damag( ratillgs oj 10 white inbl(ds ([8 (apl(88Idin their single-coss Z)Jo(jfnils in tests ot ~ til

Tllhl(d

F2X83 2

~lpaOL_ ~lp307 __ 9142-2-IL 2210-1-B ~rp30L iJpn I NC45 L501 LiOL

lIaPI _

0=110 illfestatioll

Natch(z 1ln~8 1918 t

f~aon-~r~~~~ I~~2 -Brmiddot~l(H-~-1 ~I~)Ol 1middot1rpLJ-l-~~middot~f JJ~-I

Hating - __ i

I i7 i IHO I ( )1 -

2 112 t

~--------------~ lt~ shy

_ ~

Naillf Hlltillil 1601 Ili7 I 17 (I)

1171 _ 131i (I) 1 shy on _ I a5 I

270274 171 235 I 5middott i 2 40 I 23 i on 02 LOfi

1---1-7-1-1 1 71 I

For complete explanatioll Sle p a

I 40 2 fi7 i shy221 2S31 217 213 2 Ofi I 61 1 Ia l8

lO 100

I 56 I 177

t Least significltnL diffcllIlCl at the 5-percont level is 047 t fieed IlOt IlYllilahJe

~-- -middot --1 ------- ----~-----

f I

Noinf [IUIIf IRaUIf Ratillf 1 HatllIf262 276 174 )54

1 123

I 3fi 2 74 2 3fi 2 46 i lll 140 221 2171205 L13 J ~ - ) 83 ) 13 I I middot61 )8 ) ~ t - _ bullbull l

3 99 I L 63 I l 40 2 14 ~no 261 2581109 IH3 2ul bull ______ 188 (I) 40 I 2 fi8 1 88 1_ __ _ _ _ _ _ I 00 2 I4 1 99 (I) I 1 00 __ bullbull _ 7711)2 Ins 811 75

-----shy221 2 58 202 191 L 27

~ l1 t lfl

Lim3 gtshy~ t

Rotil ~ O 62 tli I 05 Uf) 5

lfl100 ~77 l1I fi2

I 6S ~ 81 3

gtshy75 y _ __ 1-3

8 1 02 o

() o ~shyL ~ ~ o ~

--

6 TECElJJCAL BULLETlN 1160 U S DEPT OF AGRICULTURE

it 05 (onsistrntly traJ)smitting to hybrids (ar qualiti(s thut gnT( good bull prot(c-tio)) llguinst (tt1W01111 dmlUtgp Thesp obs(nutions indicuLe tha Lthe h(uyy eurOrnl damag0 ill thp Gulf (onst Stat0s gi ns it mOr0 spy(l( test for 1P5istal1(p than in UrN1S whplP th(- Nllworlll is ]lot so iLbundant al1d that mui0lial showing )lsistalJ(0 llndpr a light infestushy[ion may not gin resistllJlel undpl fl Y(JY h(iWY illfpstation

In 1946 1110 doublp-(Joss hybrid La 1030 sllO(ltI 10sistanc( in ull ((st plots at 7 10catioHs ill ~iississippi lnd 2 ill Louisiul1u In 947 n11 possib10 (omhinatiolls of t1H inhreds thalmukt up this hyhrid Wllt t(s(ld at Stah (olIPgp (0 rletermilJP -lieh in1)1((ls contrihllltd parshyoJJl11PsisiilJlCt Till datn on tl1(s( il11gt](ds and on Ln )030 and till doublp-eloss hyhrid Dixil 17 wwd for (ompnrison art gin1l in tablP 2 1110 illh1(lt1 L503 was found to he thl most nsistnnt nnd 1501 slightly resistant bull

TABLE 2 ~ (olllearwolm ria mage ralillg8 1 II(( pII((lItag(s of (a18 pound7tfesird (~f 4 ~nbr(dg (d La 1030 as (J7)I(SSU in IlIfi 8illgh-cloSS

7J1vglllils and 4 [hI doublt-(t088 hybrid~ La 1080 and TJiril 17 71l bullte8t~ at Stale (olhg( Jfisg 194

Uj(j)1501 Li4S

Entry i Enr- ]~ar- I~ar- J~ar-worm Earl worm Ear worlll Ear OlIlt Ear

damtljl inflltNl dtllllagp infptilld danlt1ge infplttpd damagl infpINI rating ratillf rltillj rat ing

PertrIIl PC((1l1 Perrenl L501 O ii4 3H 1 ~R 7 I 34 73

L Oj GGLiiO3 O )4 30 S~ ~R Lii4S I ~S 7) iiS I so sa 15GB 1)4 7] IH 1 SI

-)()l_ S] 34 1- 1 41

IIYBHllhi bullEarorm Ear

Elltry dHln~l~p illfpl (I rating

)((1

Ln JO30 I 3S 7G Dixit 17_ OO llii

O=no infltation For (olllplpumiddot (xpllIWliun P( p 3 2 Lllst ignifiel III difrlrPIlCl at til( 3-pplc(llt 1((1 i 041

Tpn whittinhlCc]s in(ll1din~ LjO] Llld Li503 W(ln ttstld in nl possiblp sill~l( (TOSSlS nt Xnt(hlz liss ill 1948 Thl datn ar0 shown ill tnbll a The 111gll ltSistfLllcP of 1501 llld L501 is dearly d(I1lonsin)icd Almost (VtIT cross with L50 or L501 J1tul a 10nI laiworm dLmnge rnting thnJ] (Ioss(s with tLllyof till other inbrpds

bull

l

bull bull bull bull 1-3

t l1 ~

() o ~ y

IAHJJI~ 3-Con e(rWOi1 damag( ratillgs oj 10 white inbl(ds ([8 (apl(88Idin their single-coss Z)Jo(jfnils in tests ot ~ til

Tllhl(d

F2X83 2

~lpaOL_ ~lp307 __ 9142-2-IL 2210-1-B ~rp30L iJpn I NC45 L501 LiOL

lIaPI _

0=110 illfestatioll

Natch(z 1ln~8 1918 t

f~aon-~r~~~~ I~~2 -Brmiddot~l(H-~-1 ~I~)Ol 1middot1rpLJ-l-~~middot~f JJ~-I

Hating - __ i

I i7 i IHO I ( )1 -

2 112 t

~--------------~ lt~ shy

_ ~

Naillf Hlltillil 1601 Ili7 I 17 (I)

1171 _ 131i (I) 1 shy on _ I a5 I

270274 171 235 I 5middott i 2 40 I 23 i on 02 LOfi

1---1-7-1-1 1 71 I

For complete explanatioll Sle p a

I 40 2 fi7 i shy221 2S31 217 213 2 Ofi I 61 1 Ia l8

lO 100

I 56 I 177

t Least significltnL diffcllIlCl at the 5-percont level is 047 t fieed IlOt IlYllilahJe

~-- -middot --1 ------- ----~-----

f I

Noinf [IUIIf IRaUIf Ratillf 1 HatllIf262 276 174 )54

1 123

I 3fi 2 74 2 3fi 2 46 i lll 140 221 2171205 L13 J ~ - ) 83 ) 13 I I middot61 )8 ) ~ t - _ bullbull l

3 99 I L 63 I l 40 2 14 ~no 261 2581109 IH3 2ul bull ______ 188 (I) 40 I 2 fi8 1 88 1_ __ _ _ _ _ _ I 00 2 I4 1 99 (I) I 1 00 __ bullbull _ 7711)2 Ins 811 75

-----shy221 2 58 202 191 L 27

~ l1 t lfl

Lim3 gtshy~ t

Rotil ~ O 62 tli I 05 Uf) 5

lfl100 ~77 l1I fi2

I 6S ~ 81 3

gtshy75 y _ __ 1-3

8 1 02 o

() o ~shyL ~ ~ o ~

--

bull bull bull bull 1-3

t l1 ~

() o ~ y

IAHJJI~ 3-Con e(rWOi1 damag( ratillgs oj 10 white inbl(ds ([8 (apl(88Idin their single-coss Z)Jo(jfnils in tests ot ~ til

Tllhl(d

F2X83 2

~lpaOL_ ~lp307 __ 9142-2-IL 2210-1-B ~rp30L iJpn I NC45 L501 LiOL

lIaPI _

0=110 illfestatioll

Natch(z 1ln~8 1918 t

f~aon-~r~~~~ I~~2 -Brmiddot~l(H-~-1 ~I~)Ol 1middot1rpLJ-l-~~middot~f JJ~-I

Hating - __ i

I i7 i IHO I ( )1 -

2 112 t

~--------------~ lt~ shy

_ ~

Naillf Hlltillil 1601 Ili7 I 17 (I)

1171 _ 131i (I) 1 shy on _ I a5 I

270274 171 235 I 5middott i 2 40 I 23 i on 02 LOfi

1---1-7-1-1 1 71 I

For complete explanatioll Sle p a

I 40 2 fi7 i shy221 2S31 217 213 2 Ofi I 61 1 Ia l8

lO 100

I 56 I 177

t Least significltnL diffcllIlCl at the 5-percont level is 047 t fieed IlOt IlYllilahJe

~-- -middot --1 ------- ----~-----

f I

Noinf [IUIIf IRaUIf Ratillf 1 HatllIf262 276 174 )54

1 123

I 3fi 2 74 2 3fi 2 46 i lll 140 221 2171205 L13 J ~ - ) 83 ) 13 I I middot61 )8 ) ~ t - _ bullbull l

3 99 I L 63 I l 40 2 14 ~no 261 2581109 IH3 2ul bull ______ 188 (I) 40 I 2 fi8 1 88 1_ __ _ _ _ _ _ I 00 2 I4 1 99 (I) I 1 00 __ bullbull _ 7711)2 Ins 811 75

-----shy221 2 58 202 191 L 27

~ l1 t lfl

Lim3 gtshy~ t

Rotil ~ O 62 tli I 05 Uf) 5

lfl100 ~77 l1I fi2

I 6S ~ 81 3

gtshy75 y _ __ 1-3

8 1 02 o

() o ~shyL ~ ~ o ~

--

8 TECIn-TJCAL BULLETIN 1160 U S DEPT OF AGRICULTURE

In these same t(sts on oPPll-pol1inntpcl yali(t~- onellin lt1oubk-rloss bullh~d)lids W(1( us(lt1 os dwCks Th(ir P01Worn1 domag( ratings wpre ns fo11o-s

EarWDTm damage

Entry Pedigree ruting Station Io~hy~ OPCJl pollinutecL ___ ___ ___ 307 Dixie 1-_ (TG1 X 113) X (Xe37 X XC3-1) 248 Dixie] 8__ (FmiddotI X 1Ci) X (CT 112 X L578L 1 48 Dixie 1L_ (TxCiDl X Ll0) X (1)2-2 X L-1-1) _ 143 La 1030 ~~ __~ [L50 I X L503) X (L5-18 X 15(9) 1 13 ris~ 8011____ (1501 X 1503) X (F-14 X FG) _~_ 86

Stotion ~rosb)c uncI Dixip 17 (1( clnssifipd as Sllsc(ptibl( wh(1(tls tll( otlHrs were rcsistnnL Dixie 18 Diie 11 anelLa 1030 hny( be(Jl 1elen8eltl for eomnwrcial productioll

Dixie 17 is it white hybrid thnt ~-i(lds well It is susceptible to 1gtl)th the ennonn and nle ri(l w((-il hut it hns 1gt(111 used Sll((ISSshy

full~- in the northlrn port of the Gulf Statls T()1]1(Issl( nnd Xorth Cnrolinu

Dixie 18 is a middotnllow Inbricl tItu t yip]ds wpll is ]esistm t to both the (Olworm nnd tfle riC( pevil nnd has px((llrnt qunlity of grnin It bull is t11( knding y(llow h)-britl of thp South It is Compospd of 1 highl~shyrpsistflnt 1 ltsistnni 1 j]ltclJllNlillt(middot nnd 1 inhl((l sllsCcptihlc to (a1W01111 (lamng( Attempts han hC(ll made to ]pplnec G1112 -hi(h is the sus(cptibl(il1br((1 with a nsistnnt inbrpd hut G1112 (on t1iblltlS slIcll duunet(listies to the dOll hlp C1OSS as d(sirnhlp (HI

siz( nnd good -ieIcL which muke it iJl(Lisp(l1snbl( nt pnSlllt Dixie 11 is 11 whit( hybrid haying intplmpdiltl lPSiStflllC( to hoth

th( (flIWOlm and thl 1i(( wP(-il It ~-ields wpll and plodu(es goodshyqunlity corll

I~n 1030 has nUlJl~- px((ll(nt Cjunliti(s It yillds w(lll stands w(ll 11l1ltl hns larWOr111 rlSistilll(P that closely approndlPs imlllunity ricp np-illlsist1111(( and top-qualit~- grain ] is r(sistnnt inblpds--L501 and LijO3--~ar( maintnin(d as a sour(( of )(Isistani gllln plnsm Howshy(Y(l hPll th(lsP ill brpds W(l( pu t ou t on a field bHSis 10] singll-cross procluCtioll as fI s(((l pn](nt for the hybrid the yidds w(rl so low that Ln 1030 (ould llotl)( jJrodll((ld eommercinl1-

riss ~O 11 has mallY of tll( desirn hlp chamdp]istics of Ln 1030 bu t it wns not lplpnsed for (OllllllCICiol p]oc1uCtion lHCIUlS( of tll( POOl )-ipld of J501 und L503 as producPls of singlt-lt1osS s(((1 bull

lln ij21 is a white hylJli(l of good qunlity fnir yjPct and lll(dium (HI-Oll1l Hllcl ric( w((vil ]Psistnnce It is d(ri(lc1 from 4 illbrCds that ha-p h((n lutpcL intlIIHpdillt( 10] (lllWOlm ](sistnl1cl 11 pn]el1is-shy(L90 X L9]) X (lA4 X L2-2)-Ti] tc at thf top of Oll in tplmed iatl group lHing i111110R( good (IJlough to bl ine1uclN1 in thC ](sistant group ThiR iR thp only COlIll1lrCial h)-brill in procLudion thnt hnR 4 intprn1(ciishynl( inhT(ltis in its lwdigrpl Its (nlOl111 dnrnng( rating (ornpnrlS fu-ornhly with that of Dixi( 18 Ln 521 iR lIspd throughout thc ri(( w(Cil l)(ltR of IJOliisiuWl JiRsissippi _labnllln flllCL Georgia

Two r(sisUmt inhl((Ls (ombin(cl into a single-tloss PlU(ut someshytinws give high PiLrW01l1l lPsistallc Dixit 18has 1 highly lPsistnnt inbrpcl au(l 1 llsistnnt inhlp(l in the sppd palPJlt F44 X F6 In La 1030 (he singlP (]oss L50l X L503 contributls llsistnl1cP Six doubleshycross hyblic1s haying L50] X L503 as 1 parent (1P all ]Psistnnt to th( rUT01rn Theil (OlWOlm damage ]fitings nnd thosp for Dixie

bull

bull

bull

bull

bull

DENT CORN LBREDS AND RYBlUDS RESISTANT 10 CORN EARWORM 9

17 and the opcH-pollinated variety Station )Iosby tested in3 10(fi tions in )lississippi fire as 1o]]ows

Place iescd and entry EtlT1Jorm damageXatchpz ruiliU

(1501 X L503) X (rp3J3 X XC45) O 25 (1501 X L503) X (L548 X L)(j9) ___ _ 2i (L501 X L503) X (IIp309 X XC45L 40 (L50l X 1503) X (lp313 X 1134851 86

Yazoo Cit (LTJOI X L5(3) X (F44 X F(n _ ____ _ _ I 40 Dixic li (161 X 113) X lXC3i XCHL 1 is Htation 101gt 265

StonciIlp (L501 X 1)03) gt( (lpl X lp412) __ 1 16 Htatioll Iob _ _ 250

Although ill( inbreds 1501 and 1503 arC vNy poor jJrodu((fS and fire not suitnbl( for use in n comn1(1cin1 hybrid the si11gle cross itself has a fU10-100king ear high-quality corn find high enrWOllll reshysista11(( (fig 2) EithN inbred crossed with unother inbred improHs

FIG1HE 2-Contmst jn appparanlP of the slIscpptible arid JcIlicorse (A) and the resistant single crosses 1501 X L503 (B) and 1503 X Fl (C)

th e q unl it) ttnd cnJ-Ollll leSistn11cc in the single ((oss Thcr([o1c enell of th(s( inbrNls pJoyid(s a yalunble SOllJ(( of l(sistant g(rlll plasm -lJidt should hp Inaintaincd HmIuscd to produ(( inbrNis that -iJlimpJon sus((ptiblt (omm(lcinl ulblcds L503 X F1 is n highly l(sistnnt singh (ross (Jig ~() FH X F0 and 1501 X L503 hnyc practicnll~ 110 (nloI11l ltlamnge as (omprul(l with such sllsc(ptible strnins ns J(Ilieols( (fig 2 -1)

Good sou]((S of llllwOJl1l-r(sibll1t germ plnsm nrc to JJl found ill otlt(] singk and double cross(s For exnmple ~rp410 Cllme from F6 X F7 n resistant singlemiddot (ross and ~Ip331 from Fla n n Jtsistnllt double (ross 111(s( inblCd )IogPluCs hn( ngronomie adYnntnlfS OVlr nny of the punnts find nl( equul or superior to thenl for NlrshyworlllllsistnlcC

SCvern] other whit( inbnds CaIT onsidcrnble carworm l(sistnl(~f llnd arc usCd in commlITinl hybrids They fllC F1 F2 F3 F4 1101 nnd LS7 TlnC( whitc single crosses (fig3) illustrnt( thl possibilities 01 using (filoJJ1l-l(sistant single crosscs in dou ])](-(IOSS hybrids 1101 X ~rp303 amI 1101 X )Ip309 hnn eUTonn )(sistan(C ns well as other tlPsirnbJc (harnct(ristics lh(~ havl rfl t11(1 Inrgl (hiel seeds which are 110t desimbl( in a s(((1 pHrent hut ther might be uSNl to

10 TECH~lCAL BrLIJET1~ 1160 r B DEPT OF AGHlCrlrUHE

good ndnlntngl us polliLt1tors ~rp3I -fpHli) Wllidl Itns also bullshowll ]esitnn(P has uniform s((cis nlHl is w(ll lIitp(l for a seed pnnll t

EnrWOlJll nisttul(p ill tIll ypllow inhn(ls hns not 1)((11 found to ((J11H1 tlult ill thp hitp inilr(ds Ill( )pllow singlltgt (IOSS jlt-l4 F0 hns h(Pll lxcpllpnt It is (11( Sl(ll panIlt 101 tlit r(sistanl hyilri(l Dixie IX ~ome of till ]lP inbrp(is ill singlp-(rns COlllbillntioll dso sho prOlllIS(

Tlw (110 singlp eross - ip 1 gt ~ [pJ 10 hus Pllworm r(sist 111(1 lwd is (x(pUpnl for a scpd plIlnt TIl( nIIO sing( (ross ~lp42(j X

nTI12 hIS possibilitils as a pollinator Thp Ilsistnncc ill lpJ2G OYlrcolll(s sus(pptibility in (1112 whi(h hns high yilld nlld thick kpJHls (Fi~ -t)

Figllrl) sltos nil (urworm-slls((p(ihll douIJI(-noss hybrid hieh Illny Ill (olllJ)nr(d wit h til( lnrwornH(sistallt sill~d( (ros( ill figllrtS 2middot1 lthOll)dl this hybrid is llot tIl( most SU(lpt ihk it indicnJ(s thc impro(JlltII( mud( t hrollgh S([pct iOIl llld colllhillation of ((rtnin illilrlds nsistallt to (Irworm dnllla~(

SOIlH husk prot((t iOIl is Iss(lltid for 1 good southern hbrid Ilow(Yr nn lxt llllllI lOll) hllsk is not IHC(SSftn or (Y(ll (PsirnhIP ill Ull pUIorm-rtSistlilt hbrid tight btl (x(llsioll of approxshyillltl ~ ill(hp IS ill (it( sillglP cross LiiOl LiO- app(nrs nmpl( for protp((jon frolll (llP ri( ((il pink S(middotuY(llglr (lltlrpillnr (PYI(JrIIC(S lilili nrlitml) birds alld (1titltling rlllll tht PlIS nrl tx]JOS((1 PH norm dnmngc is uSlIull gnLt(J l tid (Ills illsp(ts as (11 us s(pml

bull

bull DE~T ((lH~ JXBHED- AXD HYBHID- HE-rSTXT TO CORX EHOI~l I]

(a(Il~(J flip alld I)((tl( illft tl)( (ar Euorlll r((dill) in (lltrull(( ]1])(( for di(Hs(s to ltI (I[op whirl (111( k(rllll ltImiddotny Thi Ullh(ulthy cOlldition is nttrndin (0 ill((ts

bull

FHiCRE middot1-111(1 (IlOl in (J)~(~ howing PlIl()11I1 1littlIlCI Llfl Ipl IjJ-lID 1igitt IpI2limiddot (1J 12

DETERMINAllON OF VALUE OF RESISTANT HYBRIDS To iIlutrnt( hOI ]0( du( to till (Olll (Hrorlll Ill Ill rpdu((lt1

th)ou~dl d(yllo]lllllnt or r(si(nllt hybrid nn P)]uatioll was nlHdl of dallltlg( to 1 OpPll-]lollillltld Ytuilty allltl ) hybrid TIl( palOrlll dnlIIngl ratillgs tllld thl losl ill klIIl(J Pl) llI nnd ~i(]d 1)(1 1(1( lr( showll ill (d)]( -I

bull TIlII -I (IINd(illjl htwl 11 (111 (lIIIIUnlt dalJ([j( I((ill[ I (II

11I~s (II(Wr hy tit I((fJurII 10 J 1Ij)( II-JuiJt((( lIlilill (ltI(tillll J lusb) ( tI 3 It lbrids ill II slg III )IIIi (uI [I J fixs 1flp) f

Lo-~ in Ealolnl

Elltry dlI11u~-(middot Ill t illg 11111(1 [WI Yil[d ]I1

( I nIl~ 3

I r( III BIIIII~ ~tati()Jl [oIJI l () IiI a 2 j)ixi I 2 middotI 3 I I Xii-nisi IX L J II bull IS Lt J080 1 1a as ll1

10 110 illrl~tl)i()ll For (Olllp[((( (Xpill1tlioll ~(( p -l Hllld OJl liDO k(Jlt(b H 111

3 Bai(d Oil )() il1h(l~ lll1 1(1( alld [HlCllIlag1 or klllI(b d1l1WP(ll

bull

12 TI(HXICAL BFLLETIX 1160 t~ DEPT 01 AGlUlTLITHI~

bull

bull

Fl (Ill 5-----Imiddotullt fro III a US((pt iill double-cm h odd middotmiddotowinl ((1( injulmiddot by t h( (0111 (HIW()IIIl

bull

bull

bull

bull

DENT CORN INEREDS AND HYBRIDS RESISTANT TO CORN EARWORM 13

ThE percentage of keJHlls dnmaged b- the eaJWOllll in Dixie 18 was only abmxt otl6-sixth of tU)t in StnLion 1iosby Earworm loss to Ln 1030 was negligihle III nclditioll to direct loss in yield due to the enrworm the cluWorm-susceptiblP hybrids showNl furth(r losses from rice w(wvil iniestations nne from ear rots wili(h oit(n foUolshy(al-OrllliuJestnlion

SUMMARY In the South lossls (hlP to the feeding of til( (orn enIorJU (I1eliutiig

zw (Boddie)) on ems of eorn tLlllOlint Lo millions of bushds nnnually A cooperative program nts undpJtnk(1l by flw Cllitpd States Departshyment of AgrieuHlue nne til( ~lississippi A~Ii(ultUlnl ~jq)(lilllent StuJion froUl 1942 to 1951 to de(Ipase tiHse ]OSS(S through tbe br(editl~ of dent corn JI)lwids rlsistnnt Lo lftlWOJIll iUjUL DaU) were obtitinl(l on eiuworlll dnl1ULge in ill bncls through rat ing oft heir perfoIUliU I(P in single e1OSS(5 and in sillglfmiddot- uud double-cross hybrids

FiY( highly L(lsistant hite Inhleds-L501 L503 Fl F2 and ~lp313--I)ncl n hi~bly 1([1stnnl wllo inblld---F6--w(J( foulld tlwt triLllSf(r tiJ0ir rlSi5tn1l(p to Ihpil singlt-eross pJogeniJs TwPlv( white inbrpcls and 5 y(middotllow inhllds pn dassiJi0d itS lPsistnllt III ndditioll t 1]( sus((pt ibitit- of mnn ot I WI in brtCis to NlIWOIm diunagt nl~ dfttlminrd through studilS of th(il [JlJfOllllallC( in sillgll (1Oss(s

()ommelcinl Inhlill with (UWOllll rlsistnll(p tlmt are now widlh grown nl( Dixi( I 8 Dixit 11 nlHi La 521 JiXP(Iilll(lltnl dttlt) sho thnt (nIWOIIll dmnng( to Dixi( 18 is 0111 about olll-sixth of ihat to StiLlion ~l()sb

LITERATURE CITED (0 BLA(IIAIW BIPll BHCrIl Iolls n nlld SIILISC RALPII 0

HHl Im~ITAS( OF (OltS lltAlS 10 [Ill COilS 1Alt 1OH~r Jour Ampr MOe Aproll 3a 344middot-aiiO

(21 COIIIS lt X nlld KI~lII(S f H H1l7 BIIEIWIS( Igl~I (o)tS RI18TAST [0 1111 COltS EARIIOIU Jour

Apr Rp 11 i4hi72 rn DIChE F F nnd JISKISS ~rEltLI T

J9til [(IIIIIIII]1Y OF (IllIIX STI(fSS 01gt IIEII) COltS IS IIYIlHlI) (()~IIIISAIroSS Itl llA~IAW BY (OIlX EAItOlt~I l S Dept Apr Tl(h Bul Snf Hi pp

(1) DO(middotmM~ A lM7 1111 EFFEcr (n HImiddotS JXTIXSfOX A~I) 1[(l1rXIss us EAHIIOIDl

lJ~I(J- TO COIIX Jour EC)Il Ent 40 (j(jjmiddot(j(j4 (ii) PAfSIJH nEnISAI) B and BlTss()s llIIIIlt ~L

1940 1)1 FJ IlIXIIA I ISIIIY lIIlIX Y1UETIEH ISlIllll) LISl-S Axn IIYHHlDS ()Io FIEII) (OHS (AISI) [fl IIE COIlS EAHI()IDl HI1[()IIIIS IIMHl8RA (IIBXL Iuur AIr Hps (i1 81-100

o

bull

bull

bull

bull

DENT CORN LBREDS AND RYBlUDS RESISTANT 10 CORN EARWORM 9

17 and the opcH-pollinated variety Station )Iosby tested in3 10(fi tions in )lississippi fire as 1o]]ows

Place iescd and entry EtlT1Jorm damageXatchpz ruiliU

(1501 X L503) X (rp3J3 X XC45) O 25 (1501 X L503) X (L548 X L)(j9) ___ _ 2i (L501 X L503) X (IIp309 X XC45L 40 (L50l X 1503) X (lp313 X 1134851 86

Yazoo Cit (LTJOI X L5(3) X (F44 X F(n _ ____ _ _ I 40 Dixic li (161 X 113) X lXC3i XCHL 1 is Htation 101gt 265

StonciIlp (L501 X 1)03) gt( (lpl X lp412) __ 1 16 Htatioll Iob _ _ 250

Although ill( inbreds 1501 and 1503 arC vNy poor jJrodu((fS and fire not suitnbl( for use in n comn1(1cin1 hybrid the si11gle cross itself has a fU10-100king ear high-quality corn find high enrWOllll reshysista11(( (fig 2) EithN inbred crossed with unother inbred improHs

FIG1HE 2-Contmst jn appparanlP of the slIscpptible arid JcIlicorse (A) and the resistant single crosses 1501 X L503 (B) and 1503 X Fl (C)

th e q unl it) ttnd cnJ-Ollll leSistn11cc in the single ((oss Thcr([o1c enell of th(s( inbrNls pJoyid(s a yalunble SOllJ(( of l(sistant g(rlll plasm -lJidt should hp Inaintaincd HmIuscd to produ(( inbrNis that -iJlimpJon sus((ptiblt (omm(lcinl ulblcds L503 X F1 is n highly l(sistnnt singh (ross (Jig ~() FH X F0 and 1501 X L503 hnyc practicnll~ 110 (nloI11l ltlamnge as (omprul(l with such sllsc(ptible strnins ns J(Ilieols( (fig 2 -1)

Good sou]((S of llllwOJl1l-r(sibll1t germ plnsm nrc to JJl found ill otlt(] singk and double cross(s For exnmple ~rp410 Cllme from F6 X F7 n resistant singlemiddot (ross and ~Ip331 from Fla n n Jtsistnllt double (ross 111(s( inblCd )IogPluCs hn( ngronomie adYnntnlfS OVlr nny of the punnts find nl( equul or superior to thenl for NlrshyworlllllsistnlcC

SCvern] other whit( inbnds CaIT onsidcrnble carworm l(sistnl(~f llnd arc usCd in commlITinl hybrids They fllC F1 F2 F3 F4 1101 nnd LS7 TlnC( whitc single crosses (fig3) illustrnt( thl possibilities 01 using (filoJJ1l-l(sistant single crosscs in dou ])](-(IOSS hybrids 1101 X ~rp303 amI 1101 X )Ip309 hnn eUTonn )(sistan(C ns well as other tlPsirnbJc (harnct(ristics lh(~ havl rfl t11(1 Inrgl (hiel seeds which are 110t desimbl( in a s(((1 pHrent hut ther might be uSNl to

10 TECH~lCAL BrLIJET1~ 1160 r B DEPT OF AGHlCrlrUHE

good ndnlntngl us polliLt1tors ~rp3I -fpHli) Wllidl Itns also bullshowll ]esitnn(P has uniform s((cis nlHl is w(ll lIitp(l for a seed pnnll t

EnrWOlJll nisttul(p ill tIll ypllow inhn(ls hns not 1)((11 found to ((J11H1 tlult ill thp hitp inilr(ds Ill( )pllow singlltgt (IOSS jlt-l4 F0 hns h(Pll lxcpllpnt It is (11( Sl(ll panIlt 101 tlit r(sistanl hyilri(l Dixie IX ~ome of till ]lP inbrp(is ill singlp-(rns COlllbillntioll dso sho prOlllIS(

Tlw (110 singlp eross - ip 1 gt ~ [pJ 10 hus Pllworm r(sist 111(1 lwd is (x(pUpnl for a scpd plIlnt TIl( nIIO sing( (ross ~lp42(j X

nTI12 hIS possibilitils as a pollinator Thp Ilsistnncc ill lpJ2G OYlrcolll(s sus(pptibility in (1112 whi(h hns high yilld nlld thick kpJHls (Fi~ -t)

Figllrl) sltos nil (urworm-slls((p(ihll douIJI(-noss hybrid hieh Illny Ill (olllJ)nr(d wit h til( lnrwornH(sistallt sill~d( (ros( ill figllrtS 2middot1 lthOll)dl this hybrid is llot tIl( most SU(lpt ihk it indicnJ(s thc impro(JlltII( mud( t hrollgh S([pct iOIl llld colllhillation of ((rtnin illilrlds nsistallt to (Irworm dnllla~(

SOIlH husk prot((t iOIl is Iss(lltid for 1 good southern hbrid Ilow(Yr nn lxt llllllI lOll) hllsk is not IHC(SSftn or (Y(ll (PsirnhIP ill Ull pUIorm-rtSistlilt hbrid tight btl (x(llsioll of approxshyillltl ~ ill(hp IS ill (it( sillglP cross LiiOl LiO- app(nrs nmpl( for protp((jon frolll (llP ri( ((il pink S(middotuY(llglr (lltlrpillnr (PYI(JrIIC(S lilili nrlitml) birds alld (1titltling rlllll tht PlIS nrl tx]JOS((1 PH norm dnmngc is uSlIull gnLt(J l tid (Ills illsp(ts as (11 us s(pml

bull

bull DE~T ((lH~ JXBHED- AXD HYBHID- HE-rSTXT TO CORX EHOI~l I]

(a(Il~(J flip alld I)((tl( illft tl)( (ar Euorlll r((dill) in (lltrull(( ]1])(( for di(Hs(s to ltI (I[op whirl (111( k(rllll ltImiddotny Thi Ullh(ulthy cOlldition is nttrndin (0 ill((ts

bull

FHiCRE middot1-111(1 (IlOl in (J)~(~ howing PlIl()11I1 1littlIlCI Llfl Ipl IjJ-lID 1igitt IpI2limiddot (1J 12

DETERMINAllON OF VALUE OF RESISTANT HYBRIDS To iIlutrnt( hOI ]0( du( to till (Olll (Hrorlll Ill Ill rpdu((lt1

th)ou~dl d(yllo]lllllnt or r(si(nllt hybrid nn P)]uatioll was nlHdl of dallltlg( to 1 OpPll-]lollillltld Ytuilty allltl ) hybrid TIl( palOrlll dnlIIngl ratillgs tllld thl losl ill klIIl(J Pl) llI nnd ~i(]d 1)(1 1(1( lr( showll ill (d)]( -I

bull TIlII -I (IINd(illjl htwl 11 (111 (lIIIIUnlt dalJ([j( I((ill[ I (II

11I~s (II(Wr hy tit I((fJurII 10 J 1Ij)( II-JuiJt((( lIlilill (ltI(tillll J lusb) ( tI 3 It lbrids ill II slg III )IIIi (uI [I J fixs 1flp) f

Lo-~ in Ealolnl

Elltry dlI11u~-(middot Ill t illg 11111(1 [WI Yil[d ]I1

( I nIl~ 3

I r( III BIIIII~ ~tati()Jl [oIJI l () IiI a 2 j)ixi I 2 middotI 3 I I Xii-nisi IX L J II bull IS Lt J080 1 1a as ll1

10 110 illrl~tl)i()ll For (Olllp[((( (Xpill1tlioll ~(( p -l Hllld OJl liDO k(Jlt(b H 111

3 Bai(d Oil )() il1h(l~ lll1 1(1( alld [HlCllIlag1 or klllI(b d1l1WP(ll

bull

12 TI(HXICAL BFLLETIX 1160 t~ DEPT 01 AGlUlTLITHI~

bull

bull

Fl (Ill 5-----Imiddotullt fro III a US((pt iill double-cm h odd middotmiddotowinl ((1( injulmiddot by t h( (0111 (HIW()IIIl

bull

bull

bull

bull

DENT CORN INEREDS AND HYBRIDS RESISTANT TO CORN EARWORM 13

ThE percentage of keJHlls dnmaged b- the eaJWOllll in Dixie 18 was only abmxt otl6-sixth of tU)t in StnLion 1iosby Earworm loss to Ln 1030 was negligihle III nclditioll to direct loss in yield due to the enrworm the cluWorm-susceptiblP hybrids showNl furth(r losses from rice w(wvil iniestations nne from ear rots wili(h oit(n foUolshy(al-OrllliuJestnlion

SUMMARY In the South lossls (hlP to the feeding of til( (orn enIorJU (I1eliutiig

zw (Boddie)) on ems of eorn tLlllOlint Lo millions of bushds nnnually A cooperative program nts undpJtnk(1l by flw Cllitpd States Departshyment of AgrieuHlue nne til( ~lississippi A~Ii(ultUlnl ~jq)(lilllent StuJion froUl 1942 to 1951 to de(Ipase tiHse ]OSS(S through tbe br(editl~ of dent corn JI)lwids rlsistnnt Lo lftlWOJIll iUjUL DaU) were obtitinl(l on eiuworlll dnl1ULge in ill bncls through rat ing oft heir perfoIUliU I(P in single e1OSS(5 and in sillglfmiddot- uud double-cross hybrids

FiY( highly L(lsistant hite Inhleds-L501 L503 Fl F2 and ~lp313--I)ncl n hi~bly 1([1stnnl wllo inblld---F6--w(J( foulld tlwt triLllSf(r tiJ0ir rlSi5tn1l(p to Ihpil singlt-eross pJogeniJs TwPlv( white inbrpcls and 5 y(middotllow inhllds pn dassiJi0d itS lPsistnllt III ndditioll t 1]( sus((pt ibitit- of mnn ot I WI in brtCis to NlIWOIm diunagt nl~ dfttlminrd through studilS of th(il [JlJfOllllallC( in sillgll (1Oss(s

()ommelcinl Inhlill with (UWOllll rlsistnll(p tlmt are now widlh grown nl( Dixi( I 8 Dixit 11 nlHi La 521 JiXP(Iilll(lltnl dttlt) sho thnt (nIWOIIll dmnng( to Dixi( 18 is 0111 about olll-sixth of ihat to StiLlion ~l()sb

LITERATURE CITED (0 BLA(IIAIW BIPll BHCrIl Iolls n nlld SIILISC RALPII 0

HHl Im~ITAS( OF (OltS lltAlS 10 [Ill COilS 1Alt 1OH~r Jour Ampr MOe Aproll 3a 344middot-aiiO

(21 COIIIS lt X nlld KI~lII(S f H H1l7 BIIEIWIS( Igl~I (o)tS RI18TAST [0 1111 COltS EARIIOIU Jour

Apr Rp 11 i4hi72 rn DIChE F F nnd JISKISS ~rEltLI T

J9til [(IIIIIIII]1Y OF (IllIIX STI(fSS 01gt IIEII) COltS IS IIYIlHlI) (()~IIIISAIroSS Itl llA~IAW BY (OIlX EAItOlt~I l S Dept Apr Tl(h Bul Snf Hi pp

(1) DO(middotmM~ A lM7 1111 EFFEcr (n HImiddotS JXTIXSfOX A~I) 1[(l1rXIss us EAHIIOIDl

lJ~I(J- TO COIIX Jour EC)Il Ent 40 (j(jjmiddot(j(j4 (ii) PAfSIJH nEnISAI) B and BlTss()s llIIIIlt ~L

1940 1)1 FJ IlIXIIA I ISIIIY lIIlIX Y1UETIEH ISlIllll) LISl-S Axn IIYHHlDS ()Io FIEII) (OHS (AISI) [fl IIE COIlS EAHI()IDl HI1[()IIIIS IIMHl8RA (IIBXL Iuur AIr Hps (i1 81-100

o

10 TECH~lCAL BrLIJET1~ 1160 r B DEPT OF AGHlCrlrUHE

good ndnlntngl us polliLt1tors ~rp3I -fpHli) Wllidl Itns also bullshowll ]esitnn(P has uniform s((cis nlHl is w(ll lIitp(l for a seed pnnll t

EnrWOlJll nisttul(p ill tIll ypllow inhn(ls hns not 1)((11 found to ((J11H1 tlult ill thp hitp inilr(ds Ill( )pllow singlltgt (IOSS jlt-l4 F0 hns h(Pll lxcpllpnt It is (11( Sl(ll panIlt 101 tlit r(sistanl hyilri(l Dixie IX ~ome of till ]lP inbrp(is ill singlp-(rns COlllbillntioll dso sho prOlllIS(

Tlw (110 singlp eross - ip 1 gt ~ [pJ 10 hus Pllworm r(sist 111(1 lwd is (x(pUpnl for a scpd plIlnt TIl( nIIO sing( (ross ~lp42(j X

nTI12 hIS possibilitils as a pollinator Thp Ilsistnncc ill lpJ2G OYlrcolll(s sus(pptibility in (1112 whi(h hns high yilld nlld thick kpJHls (Fi~ -t)

Figllrl) sltos nil (urworm-slls((p(ihll douIJI(-noss hybrid hieh Illny Ill (olllJ)nr(d wit h til( lnrwornH(sistallt sill~d( (ros( ill figllrtS 2middot1 lthOll)dl this hybrid is llot tIl( most SU(lpt ihk it indicnJ(s thc impro(JlltII( mud( t hrollgh S([pct iOIl llld colllhillation of ((rtnin illilrlds nsistallt to (Irworm dnllla~(

SOIlH husk prot((t iOIl is Iss(lltid for 1 good southern hbrid Ilow(Yr nn lxt llllllI lOll) hllsk is not IHC(SSftn or (Y(ll (PsirnhIP ill Ull pUIorm-rtSistlilt hbrid tight btl (x(llsioll of approxshyillltl ~ ill(hp IS ill (it( sillglP cross LiiOl LiO- app(nrs nmpl( for protp((jon frolll (llP ri( ((il pink S(middotuY(llglr (lltlrpillnr (PYI(JrIIC(S lilili nrlitml) birds alld (1titltling rlllll tht PlIS nrl tx]JOS((1 PH norm dnmngc is uSlIull gnLt(J l tid (Ills illsp(ts as (11 us s(pml

bull

bull DE~T ((lH~ JXBHED- AXD HYBHID- HE-rSTXT TO CORX EHOI~l I]

(a(Il~(J flip alld I)((tl( illft tl)( (ar Euorlll r((dill) in (lltrull(( ]1])(( for di(Hs(s to ltI (I[op whirl (111( k(rllll ltImiddotny Thi Ullh(ulthy cOlldition is nttrndin (0 ill((ts

bull

FHiCRE middot1-111(1 (IlOl in (J)~(~ howing PlIl()11I1 1littlIlCI Llfl Ipl IjJ-lID 1igitt IpI2limiddot (1J 12

DETERMINAllON OF VALUE OF RESISTANT HYBRIDS To iIlutrnt( hOI ]0( du( to till (Olll (Hrorlll Ill Ill rpdu((lt1

th)ou~dl d(yllo]lllllnt or r(si(nllt hybrid nn P)]uatioll was nlHdl of dallltlg( to 1 OpPll-]lollillltld Ytuilty allltl ) hybrid TIl( palOrlll dnlIIngl ratillgs tllld thl losl ill klIIl(J Pl) llI nnd ~i(]d 1)(1 1(1( lr( showll ill (d)]( -I

bull TIlII -I (IINd(illjl htwl 11 (111 (lIIIIUnlt dalJ([j( I((ill[ I (II

11I~s (II(Wr hy tit I((fJurII 10 J 1Ij)( II-JuiJt((( lIlilill (ltI(tillll J lusb) ( tI 3 It lbrids ill II slg III )IIIi (uI [I J fixs 1flp) f

Lo-~ in Ealolnl

Elltry dlI11u~-(middot Ill t illg 11111(1 [WI Yil[d ]I1

( I nIl~ 3

I r( III BIIIII~ ~tati()Jl [oIJI l () IiI a 2 j)ixi I 2 middotI 3 I I Xii-nisi IX L J II bull IS Lt J080 1 1a as ll1

10 110 illrl~tl)i()ll For (Olllp[((( (Xpill1tlioll ~(( p -l Hllld OJl liDO k(Jlt(b H 111

3 Bai(d Oil )() il1h(l~ lll1 1(1( alld [HlCllIlag1 or klllI(b d1l1WP(ll

bull

12 TI(HXICAL BFLLETIX 1160 t~ DEPT 01 AGlUlTLITHI~

bull

bull

Fl (Ill 5-----Imiddotullt fro III a US((pt iill double-cm h odd middotmiddotowinl ((1( injulmiddot by t h( (0111 (HIW()IIIl

bull

bull

bull

bull

DENT CORN INEREDS AND HYBRIDS RESISTANT TO CORN EARWORM 13

ThE percentage of keJHlls dnmaged b- the eaJWOllll in Dixie 18 was only abmxt otl6-sixth of tU)t in StnLion 1iosby Earworm loss to Ln 1030 was negligihle III nclditioll to direct loss in yield due to the enrworm the cluWorm-susceptiblP hybrids showNl furth(r losses from rice w(wvil iniestations nne from ear rots wili(h oit(n foUolshy(al-OrllliuJestnlion

SUMMARY In the South lossls (hlP to the feeding of til( (orn enIorJU (I1eliutiig

zw (Boddie)) on ems of eorn tLlllOlint Lo millions of bushds nnnually A cooperative program nts undpJtnk(1l by flw Cllitpd States Departshyment of AgrieuHlue nne til( ~lississippi A~Ii(ultUlnl ~jq)(lilllent StuJion froUl 1942 to 1951 to de(Ipase tiHse ]OSS(S through tbe br(editl~ of dent corn JI)lwids rlsistnnt Lo lftlWOJIll iUjUL DaU) were obtitinl(l on eiuworlll dnl1ULge in ill bncls through rat ing oft heir perfoIUliU I(P in single e1OSS(5 and in sillglfmiddot- uud double-cross hybrids

FiY( highly L(lsistant hite Inhleds-L501 L503 Fl F2 and ~lp313--I)ncl n hi~bly 1([1stnnl wllo inblld---F6--w(J( foulld tlwt triLllSf(r tiJ0ir rlSi5tn1l(p to Ihpil singlt-eross pJogeniJs TwPlv( white inbrpcls and 5 y(middotllow inhllds pn dassiJi0d itS lPsistnllt III ndditioll t 1]( sus((pt ibitit- of mnn ot I WI in brtCis to NlIWOIm diunagt nl~ dfttlminrd through studilS of th(il [JlJfOllllallC( in sillgll (1Oss(s

()ommelcinl Inhlill with (UWOllll rlsistnll(p tlmt are now widlh grown nl( Dixi( I 8 Dixit 11 nlHi La 521 JiXP(Iilll(lltnl dttlt) sho thnt (nIWOIIll dmnng( to Dixi( 18 is 0111 about olll-sixth of ihat to StiLlion ~l()sb

LITERATURE CITED (0 BLA(IIAIW BIPll BHCrIl Iolls n nlld SIILISC RALPII 0

HHl Im~ITAS( OF (OltS lltAlS 10 [Ill COilS 1Alt 1OH~r Jour Ampr MOe Aproll 3a 344middot-aiiO

(21 COIIIS lt X nlld KI~lII(S f H H1l7 BIIEIWIS( Igl~I (o)tS RI18TAST [0 1111 COltS EARIIOIU Jour

Apr Rp 11 i4hi72 rn DIChE F F nnd JISKISS ~rEltLI T

J9til [(IIIIIIII]1Y OF (IllIIX STI(fSS 01gt IIEII) COltS IS IIYIlHlI) (()~IIIISAIroSS Itl llA~IAW BY (OIlX EAItOlt~I l S Dept Apr Tl(h Bul Snf Hi pp

(1) DO(middotmM~ A lM7 1111 EFFEcr (n HImiddotS JXTIXSfOX A~I) 1[(l1rXIss us EAHIIOIDl

lJ~I(J- TO COIIX Jour EC)Il Ent 40 (j(jjmiddot(j(j4 (ii) PAfSIJH nEnISAI) B and BlTss()s llIIIIlt ~L

1940 1)1 FJ IlIXIIA I ISIIIY lIIlIX Y1UETIEH ISlIllll) LISl-S Axn IIYHHlDS ()Io FIEII) (OHS (AISI) [fl IIE COIlS EAHI()IDl HI1[()IIIIS IIMHl8RA (IIBXL Iuur AIr Hps (i1 81-100

o

bull DE~T ((lH~ JXBHED- AXD HYBHID- HE-rSTXT TO CORX EHOI~l I]

(a(Il~(J flip alld I)((tl( illft tl)( (ar Euorlll r((dill) in (lltrull(( ]1])(( for di(Hs(s to ltI (I[op whirl (111( k(rllll ltImiddotny Thi Ullh(ulthy cOlldition is nttrndin (0 ill((ts

bull

FHiCRE middot1-111(1 (IlOl in (J)~(~ howing PlIl()11I1 1littlIlCI Llfl Ipl IjJ-lID 1igitt IpI2limiddot (1J 12

DETERMINAllON OF VALUE OF RESISTANT HYBRIDS To iIlutrnt( hOI ]0( du( to till (Olll (Hrorlll Ill Ill rpdu((lt1

th)ou~dl d(yllo]lllllnt or r(si(nllt hybrid nn P)]uatioll was nlHdl of dallltlg( to 1 OpPll-]lollillltld Ytuilty allltl ) hybrid TIl( palOrlll dnlIIngl ratillgs tllld thl losl ill klIIl(J Pl) llI nnd ~i(]d 1)(1 1(1( lr( showll ill (d)]( -I

bull TIlII -I (IINd(illjl htwl 11 (111 (lIIIIUnlt dalJ([j( I((ill[ I (II

11I~s (II(Wr hy tit I((fJurII 10 J 1Ij)( II-JuiJt((( lIlilill (ltI(tillll J lusb) ( tI 3 It lbrids ill II slg III )IIIi (uI [I J fixs 1flp) f

Lo-~ in Ealolnl

Elltry dlI11u~-(middot Ill t illg 11111(1 [WI Yil[d ]I1

( I nIl~ 3

I r( III BIIIII~ ~tati()Jl [oIJI l () IiI a 2 j)ixi I 2 middotI 3 I I Xii-nisi IX L J II bull IS Lt J080 1 1a as ll1

10 110 illrl~tl)i()ll For (Olllp[((( (Xpill1tlioll ~(( p -l Hllld OJl liDO k(Jlt(b H 111

3 Bai(d Oil )() il1h(l~ lll1 1(1( alld [HlCllIlag1 or klllI(b d1l1WP(ll

bull

12 TI(HXICAL BFLLETIX 1160 t~ DEPT 01 AGlUlTLITHI~

bull

bull

Fl (Ill 5-----Imiddotullt fro III a US((pt iill double-cm h odd middotmiddotowinl ((1( injulmiddot by t h( (0111 (HIW()IIIl

bull

bull

bull

bull

DENT CORN INEREDS AND HYBRIDS RESISTANT TO CORN EARWORM 13

ThE percentage of keJHlls dnmaged b- the eaJWOllll in Dixie 18 was only abmxt otl6-sixth of tU)t in StnLion 1iosby Earworm loss to Ln 1030 was negligihle III nclditioll to direct loss in yield due to the enrworm the cluWorm-susceptiblP hybrids showNl furth(r losses from rice w(wvil iniestations nne from ear rots wili(h oit(n foUolshy(al-OrllliuJestnlion

SUMMARY In the South lossls (hlP to the feeding of til( (orn enIorJU (I1eliutiig

zw (Boddie)) on ems of eorn tLlllOlint Lo millions of bushds nnnually A cooperative program nts undpJtnk(1l by flw Cllitpd States Departshyment of AgrieuHlue nne til( ~lississippi A~Ii(ultUlnl ~jq)(lilllent StuJion froUl 1942 to 1951 to de(Ipase tiHse ]OSS(S through tbe br(editl~ of dent corn JI)lwids rlsistnnt Lo lftlWOJIll iUjUL DaU) were obtitinl(l on eiuworlll dnl1ULge in ill bncls through rat ing oft heir perfoIUliU I(P in single e1OSS(5 and in sillglfmiddot- uud double-cross hybrids

FiY( highly L(lsistant hite Inhleds-L501 L503 Fl F2 and ~lp313--I)ncl n hi~bly 1([1stnnl wllo inblld---F6--w(J( foulld tlwt triLllSf(r tiJ0ir rlSi5tn1l(p to Ihpil singlt-eross pJogeniJs TwPlv( white inbrpcls and 5 y(middotllow inhllds pn dassiJi0d itS lPsistnllt III ndditioll t 1]( sus((pt ibitit- of mnn ot I WI in brtCis to NlIWOIm diunagt nl~ dfttlminrd through studilS of th(il [JlJfOllllallC( in sillgll (1Oss(s

()ommelcinl Inhlill with (UWOllll rlsistnll(p tlmt are now widlh grown nl( Dixi( I 8 Dixit 11 nlHi La 521 JiXP(Iilll(lltnl dttlt) sho thnt (nIWOIIll dmnng( to Dixi( 18 is 0111 about olll-sixth of ihat to StiLlion ~l()sb

LITERATURE CITED (0 BLA(IIAIW BIPll BHCrIl Iolls n nlld SIILISC RALPII 0

HHl Im~ITAS( OF (OltS lltAlS 10 [Ill COilS 1Alt 1OH~r Jour Ampr MOe Aproll 3a 344middot-aiiO

(21 COIIIS lt X nlld KI~lII(S f H H1l7 BIIEIWIS( Igl~I (o)tS RI18TAST [0 1111 COltS EARIIOIU Jour

Apr Rp 11 i4hi72 rn DIChE F F nnd JISKISS ~rEltLI T

J9til [(IIIIIIII]1Y OF (IllIIX STI(fSS 01gt IIEII) COltS IS IIYIlHlI) (()~IIIISAIroSS Itl llA~IAW BY (OIlX EAItOlt~I l S Dept Apr Tl(h Bul Snf Hi pp

(1) DO(middotmM~ A lM7 1111 EFFEcr (n HImiddotS JXTIXSfOX A~I) 1[(l1rXIss us EAHIIOIDl

lJ~I(J- TO COIIX Jour EC)Il Ent 40 (j(jjmiddot(j(j4 (ii) PAfSIJH nEnISAI) B and BlTss()s llIIIIlt ~L

1940 1)1 FJ IlIXIIA I ISIIIY lIIlIX Y1UETIEH ISlIllll) LISl-S Axn IIYHHlDS ()Io FIEII) (OHS (AISI) [fl IIE COIlS EAHI()IDl HI1[()IIIIS IIMHl8RA (IIBXL Iuur AIr Hps (i1 81-100

o

12 TI(HXICAL BFLLETIX 1160 t~ DEPT 01 AGlUlTLITHI~

bull

bull

Fl (Ill 5-----Imiddotullt fro III a US((pt iill double-cm h odd middotmiddotowinl ((1( injulmiddot by t h( (0111 (HIW()IIIl

bull

bull

bull

bull

DENT CORN INEREDS AND HYBRIDS RESISTANT TO CORN EARWORM 13

ThE percentage of keJHlls dnmaged b- the eaJWOllll in Dixie 18 was only abmxt otl6-sixth of tU)t in StnLion 1iosby Earworm loss to Ln 1030 was negligihle III nclditioll to direct loss in yield due to the enrworm the cluWorm-susceptiblP hybrids showNl furth(r losses from rice w(wvil iniestations nne from ear rots wili(h oit(n foUolshy(al-OrllliuJestnlion

SUMMARY In the South lossls (hlP to the feeding of til( (orn enIorJU (I1eliutiig

zw (Boddie)) on ems of eorn tLlllOlint Lo millions of bushds nnnually A cooperative program nts undpJtnk(1l by flw Cllitpd States Departshyment of AgrieuHlue nne til( ~lississippi A~Ii(ultUlnl ~jq)(lilllent StuJion froUl 1942 to 1951 to de(Ipase tiHse ]OSS(S through tbe br(editl~ of dent corn JI)lwids rlsistnnt Lo lftlWOJIll iUjUL DaU) were obtitinl(l on eiuworlll dnl1ULge in ill bncls through rat ing oft heir perfoIUliU I(P in single e1OSS(5 and in sillglfmiddot- uud double-cross hybrids

FiY( highly L(lsistant hite Inhleds-L501 L503 Fl F2 and ~lp313--I)ncl n hi~bly 1([1stnnl wllo inblld---F6--w(J( foulld tlwt triLllSf(r tiJ0ir rlSi5tn1l(p to Ihpil singlt-eross pJogeniJs TwPlv( white inbrpcls and 5 y(middotllow inhllds pn dassiJi0d itS lPsistnllt III ndditioll t 1]( sus((pt ibitit- of mnn ot I WI in brtCis to NlIWOIm diunagt nl~ dfttlminrd through studilS of th(il [JlJfOllllallC( in sillgll (1Oss(s

()ommelcinl Inhlill with (UWOllll rlsistnll(p tlmt are now widlh grown nl( Dixi( I 8 Dixit 11 nlHi La 521 JiXP(Iilll(lltnl dttlt) sho thnt (nIWOIIll dmnng( to Dixi( 18 is 0111 about olll-sixth of ihat to StiLlion ~l()sb

LITERATURE CITED (0 BLA(IIAIW BIPll BHCrIl Iolls n nlld SIILISC RALPII 0

HHl Im~ITAS( OF (OltS lltAlS 10 [Ill COilS 1Alt 1OH~r Jour Ampr MOe Aproll 3a 344middot-aiiO

(21 COIIIS lt X nlld KI~lII(S f H H1l7 BIIEIWIS( Igl~I (o)tS RI18TAST [0 1111 COltS EARIIOIU Jour

Apr Rp 11 i4hi72 rn DIChE F F nnd JISKISS ~rEltLI T

J9til [(IIIIIIII]1Y OF (IllIIX STI(fSS 01gt IIEII) COltS IS IIYIlHlI) (()~IIIISAIroSS Itl llA~IAW BY (OIlX EAItOlt~I l S Dept Apr Tl(h Bul Snf Hi pp

(1) DO(middotmM~ A lM7 1111 EFFEcr (n HImiddotS JXTIXSfOX A~I) 1[(l1rXIss us EAHIIOIDl

lJ~I(J- TO COIIX Jour EC)Il Ent 40 (j(jjmiddot(j(j4 (ii) PAfSIJH nEnISAI) B and BlTss()s llIIIIlt ~L

1940 1)1 FJ IlIXIIA I ISIIIY lIIlIX Y1UETIEH ISlIllll) LISl-S Axn IIYHHlDS ()Io FIEII) (OHS (AISI) [fl IIE COIlS EAHI()IDl HI1[()IIIIS IIMHl8RA (IIBXL Iuur AIr Hps (i1 81-100

o

bull

bull

bull

DENT CORN INEREDS AND HYBRIDS RESISTANT TO CORN EARWORM 13

ThE percentage of keJHlls dnmaged b- the eaJWOllll in Dixie 18 was only abmxt otl6-sixth of tU)t in StnLion 1iosby Earworm loss to Ln 1030 was negligihle III nclditioll to direct loss in yield due to the enrworm the cluWorm-susceptiblP hybrids showNl furth(r losses from rice w(wvil iniestations nne from ear rots wili(h oit(n foUolshy(al-OrllliuJestnlion

SUMMARY In the South lossls (hlP to the feeding of til( (orn enIorJU (I1eliutiig

zw (Boddie)) on ems of eorn tLlllOlint Lo millions of bushds nnnually A cooperative program nts undpJtnk(1l by flw Cllitpd States Departshyment of AgrieuHlue nne til( ~lississippi A~Ii(ultUlnl ~jq)(lilllent StuJion froUl 1942 to 1951 to de(Ipase tiHse ]OSS(S through tbe br(editl~ of dent corn JI)lwids rlsistnnt Lo lftlWOJIll iUjUL DaU) were obtitinl(l on eiuworlll dnl1ULge in ill bncls through rat ing oft heir perfoIUliU I(P in single e1OSS(5 and in sillglfmiddot- uud double-cross hybrids

FiY( highly L(lsistant hite Inhleds-L501 L503 Fl F2 and ~lp313--I)ncl n hi~bly 1([1stnnl wllo inblld---F6--w(J( foulld tlwt triLllSf(r tiJ0ir rlSi5tn1l(p to Ihpil singlt-eross pJogeniJs TwPlv( white inbrpcls and 5 y(middotllow inhllds pn dassiJi0d itS lPsistnllt III ndditioll t 1]( sus((pt ibitit- of mnn ot I WI in brtCis to NlIWOIm diunagt nl~ dfttlminrd through studilS of th(il [JlJfOllllallC( in sillgll (1Oss(s

()ommelcinl Inhlill with (UWOllll rlsistnll(p tlmt are now widlh grown nl( Dixi( I 8 Dixit 11 nlHi La 521 JiXP(Iilll(lltnl dttlt) sho thnt (nIWOIIll dmnng( to Dixi( 18 is 0111 about olll-sixth of ihat to StiLlion ~l()sb

LITERATURE CITED (0 BLA(IIAIW BIPll BHCrIl Iolls n nlld SIILISC RALPII 0

HHl Im~ITAS( OF (OltS lltAlS 10 [Ill COilS 1Alt 1OH~r Jour Ampr MOe Aproll 3a 344middot-aiiO

(21 COIIIS lt X nlld KI~lII(S f H H1l7 BIIEIWIS( Igl~I (o)tS RI18TAST [0 1111 COltS EARIIOIU Jour

Apr Rp 11 i4hi72 rn DIChE F F nnd JISKISS ~rEltLI T

J9til [(IIIIIIII]1Y OF (IllIIX STI(fSS 01gt IIEII) COltS IS IIYIlHlI) (()~IIIISAIroSS Itl llA~IAW BY (OIlX EAItOlt~I l S Dept Apr Tl(h Bul Snf Hi pp

(1) DO(middotmM~ A lM7 1111 EFFEcr (n HImiddotS JXTIXSfOX A~I) 1[(l1rXIss us EAHIIOIDl

lJ~I(J- TO COIIX Jour EC)Il Ent 40 (j(jjmiddot(j(j4 (ii) PAfSIJH nEnISAI) B and BlTss()s llIIIIlt ~L

1940 1)1 FJ IlIXIIA I ISIIIY lIIlIX Y1UETIEH ISlIllll) LISl-S Axn IIYHHlDS ()Io FIEII) (OHS (AISI) [fl IIE COIlS EAHI()IDl HI1[()IIIIS IIMHl8RA (IIBXL Iuur AIr Hps (i1 81-100

o

bull

bull