Embed Size (px)
Citation preview
University of Nigeria Research Publications
UDEALOR, Anselm
Aut
hor
PG/M.Sc/
Title
Effect of Tobacco (Nicotians Tabacum L.) on the Early Growth and Development of Interplanted Cassava (Mainhot Esculenta
Crantz)
Facu
lty
Agriculture
Dep
artm
ent
Crop Science
Dat
e
June, 1981
Sign
atur
e
EFFECT OF TOBACCO (Jlicotiana tabacum L.) ON THE
EARLY GROWTH AND DEVELOPMENT OF
INTERPLANTED CASSAVA
( ~ a n i h o t esculenta Crantz)
A Thesis P r e s e n t e d
BY
UDEALOR, ANSELM B .Sc . (HONS) (N IG)
I N PARTIAL FULFILKENT OF THE REQUIREMENT FOR THE
DEGREE OF MASTER OF SCIENCE I N THE
FACULTY OF AGRICULTURE
UNIVERSITY OF N IGERIA 1
NSUKKA
DEPARTMENT OF CROP SCIENCE
UNIVERSITY OF N IGERIA
NSUKK A
JUNE 1981
i i CERTIFICATION BY SUPERVISOR
I c e r t i f y t h a t t h e work r e p o r t e d h e r e i n was
c a r r i e d out by A. Udealor , i n t h e Department o f
Crop Science, U n i v e r s i t y o f Nxger ia, Nsukka.
fi* . EZEOINWA
SUPERVISOR
iii
DEDICATION
To my Mother and w i f e
TABLE OF CONTENTS PAGE
C e r t i f i c a t i o n
Dedica t ion
Table of Con ten t s
Acknowlodgernent
List o f Tables
L i s t of F i g u r e s
Abs t rac t
I n t r o d u c t i o n
L i t e r a t u r e Review
M a t e r i a l s and Mothod
R e s u l t s and Discuss ion
Summary and Conclusion
References
. . ii
.. iii
. . i v
. . V
.. v i
. . v i i i
.. i x
. . 1
. . 3
.. 11
.. 15
. . 48
. . 50
ACKNOWLEDGEMENTS
I am s i n c e r e l y g r a t e f u l t o t h e D i r e c t o r and
Governing Board o f t h e N a t i o n a l Root Crop Resea rch
I n s t i t u t o , Umudike who s p o n s o r e d t h i s work.
I am a l s o i n d e b t e d t o my S u p e r v i s o r ,
P r o f e s s o r F.O.C. Ezedinma, Dean o f t h e F a c u l t y o f
A g r i c u l u t r e , f o r * h i s gu)ance, and u n t i r i n g a d v i c e d u r i n g
t h e d e s i g n i n g , e x e c u t i o n , a n a l y s i s and p r o d u c t i o n o f t h i s
work; t h e Head o f Department o f Crop S c i e n c e ,
Dr E.U, Okpala f o r p r o v i d i n g a l l m a t e r i a l s r e q u i r e d d u r i n g
t h e r e s e a r c h .
My t h a n k s a l s o go t o Dr. I.U. Obi , a L e c t u r e r i n t h e
Depar tment of Crop S c i e n c e , f o r h i s a d v i c e on s t a t i s t i c a l
a n a l y s i s and f o r r e a d i n g and c r i t i c i z i n g t h e - d r a f t ;
O r C. I l o b a , a L e c t u r e r i n t h e Depar tment o f Crop Sc ience ,
who a l s o c r i t i c i z e d t h e d r a f t and Dr J.E. Asiegbu a l s o a
L e c t u r e r i n t h e Depar tment f o r h i s o c c a s i o n a l s u g g e s t i o n s ,
I owe a l o t t o Mr B.C. Onaku, a f e i l o w g r a d u a t e s t u d e n t ,
w i t h o u t whose p r i c e l e s s h e l p t h e f i e l d work would have been
f e l t ; f l e s s r s . J.J. Or j i ekwe , J.I. Anunwa, D.G. I b e , T.O.S.
Okebugwu and o t h e r p e r s o n n e l s o f t h e Depar tment o f Crop
S c i e n c e who i n one way o r t h e o t h e r h e l p e d t h e a u t h o r i n
t h i s r e s e a r c h ,
F i n a l l y t h e a ~ t h o r w i s h e s t o t h a n k flr Mike C. Nwafor
who t y p e d t h e m a n u s c r i p t .
v i L i s t o f Tables
Tab le Page
1 E f f e c t o f Time o f I n t e r p l a n t i n g Cassava t h r o u g h
Tobacco on The H e i g h t o f Cassava With Time .. 18
2. E f f e c t o f Time o f I n t e r p l a n t i n g Cassava t h r o u g h
Tobacco on t h e l e n g t h o f t h e 5 t h I n t e r n o d e o f
Cassava wi th Time . C .. 21
3. E f f e c t o f T i m ~ of I n t e r p l a n t i n g Cassava t h r o u g h
Tobacco on t h e G i r t h o f Cassava stems wi th Time .. 22
4. E f f e c t o f Time o f I n t e r p l a n t i n g Cassava t h r o u g h
Tobacco on t h e Canopy Diameter o f Cassava w i t h
Time . . . . .. 24
5. E f f e c t o f Time o f I n t e r p l a n t i n g on t h e Number o f
Cassava Leaves With Time . . . . 26
6. E f f e c t o f I n t e r p l a n t i n g Cassava Through Tobacco
on t h e F resh Weight (g /p lan t ) o f Cassava
Storage Root a t 3 Months a f t e r P l a n t i n g and a t
2 Months a f t e r F i n a l Harves t o f Tobacco .. 33
7. E f f e c t o f Time o f I n t e r p l a n t i n g Cassava Through
Tobacco on t h e F resh Weight (g /p lan t ) o f
Cassava Storage Roots a t 3 months a f t e r p l a n t i n g
and a t 2months a f t e r f i n o 1 h a r v e s t o f Tobacco .. 34 - L
8. E f f e c t o f I n t e r p l a n t i n g on t h e D i s t r i b u t i o n o f
D r y m a t t e r among v a r i o u s organs o f cassava t h r e e
months a f t e r p!. .nt ing . . . .
Table
v i i
Page
9, E f f e c t o f Time o f I n t e r p l a n t i n g on t h e
D i s t r i b u t i o n o f Dry f l a t t e r among v a r i o u s organs
o f Cassava t h r e e months a f t e r p l a n t i n g .. .. 38
10. E f f e c t o f Time o f I n t e r p l a n t i n g on t h e
D i s t r i b u t i o n o f Dry M a t t e r among v a r i o u s
organs o f cassava two months a f t e r f i n a l
tobacco h a r v e s t . . . . . . 39
11. E f f e c t o f I n t e r p l a n t i n g on t h e percentage o f
Dry f l a t t e r i n v a r i o u s organs o f cassava t h r e e
months a f t e r p l a n t i n g .. .. . . 41
12. E f f e c t o f I n t e r p l a n t i n g on t h e percentage o f
D ry f l a t t e r i n v a r i o u s organs o f cassava two
months a f t e r f i n a l h a r v e s t o f Tobacco . . .. 42
13, E f f e c t o f Time o f I n t e r p l a n t i n g on t h e
percentage o f D ry f l a t t e r i n v a r i o u s organs o f
cassava t h r e e months a f t e r p l a n t i n g . . .. 44
14, E f f e c t o f Time o f I n t e r p l a n t i n g on t h e
percentage o f Dry f l a t t e r i n v a r i o u s organs o f
cassava two months a f t e r f i n a l h a r v e s t o f . *
Tobacco . . . . .. 45
L i s t o f F igures F igu re
v i i i
Page
E f f e c t o f I n t e r p l a n t i n g Cassava Through
Tobacco on The Height o f Cassava .* 17
EfPect o f I n t e r p l a n t i n g Cassava Through
Tobacco on The Length o f The 5 t h In te rnode
o f Cassava . . . .. 19
E f f e c t o f I n t e r p l a n t i n g Cassava Through
Tobacco on The G i r t h o f Cassava Stem .. . 20
E f f e c t o f Time o f I n t e r p l a n t i n g Cassava
Through Tobacco on The Leaf Area o f
Cassava + .. . 28
E f f e c t o f T ine o f I n t e r p l a n t i n g Cassava
Through Tobacco on The Leaf Area Index
(LAI) o f Cassava . . .. .. 29
E f f e c t o f Time o f I n t e r p l a n t i n g Cassava
Through 7'obacco on The Rate o f Increase o f
Leaf Area Index (LAI) o f Cassava .. .. 30
ABSTRACT
The e f f e c t o f i n t e r p l a n t i n g cassava ( c u l t i v a r 60506)
t h r o u g h tobacco a t weekly i n t e r v a l s ove r f o u r weeks on
e a r l y g rowth and development o f cassava was s t u d i e d a t
t h o U n i v e r s i t y o f N i g e r i a Teaching and Research Farm,
L a t i t u d e 06'52 N.
Growth and y i e l d o f Tobacco were n o t a f f e c t e d by
i n t e r p l a n t e d cassava a t any o f t h e p l a n t i n g dat;-L-tudied.
Number o f stems developed by cassava was not a f f e c t e d by
i n t e r p l a n t i n g .o r t i m e o f i n t e r p l a n t i n g , b u t p l a n t h e i g h t ,
l e n g t h o f i n t e r n o d e s and stem g i r t h , decreased wi th
de layed i n t e r p l a n t i n g . I n t e r p l a n t e d cassava was more
, s p i n d l y w i t h l o n g e r i n t e r n o d e s t h a n s o l e c r o p cassava,
Leaf a rea development i n cassava was s i g n i f i c a n t l y
a f f e c t e d b y t i m e o f i n t e r p l a n t i n g , with number o f l e a v e s
and l e a f a rea i n d i c e s b e i n g h i g h e r a t e a r l i e r t h a n l a t e r .
p l a n t i n g .
F r e s h we igh t and d r y m a t t e r y i e l d s o f s t o r a g e
r o o t s were reduced wi th de layed i n t e r p l a n t i n g o f cassava.
However, cassava appeared t o r e c o v e r f rom t h e adverse
c o m p e t i t i v e e f f e c t s s h o r t l y a f t e r t h e tobacco h a r v e s t
was completed. - c-
1
INTRODUCTION
Cassava (Manihot escu len ta Crantz) i s a long-season
r o o t crop, which i s s u i t e d t o mixed-cropping w i t h s h o r t
te rm crops. I n Southern N ige r i a , i t i s u s u a l l y grown i n
combinat ion w i t h o the r annual crops, Such as yams,
cocoyams, okra, melon and beans. Sometimes i t i s
i n t e r p l a n t e d through o i l palm, cocoa and o t h e r p e r e n n i e l
p l a n t a t i o n crops.
Tobacco ( ~ i c o t i a n a tabacum L.), on t h e o t h e r hand, is
a s h o r t term l e a f c rop u s u a l l y grown i n s o l e c u l t u r e .
Mixed c ropp ing i n v o l v i n g i n t e r c r o p p i n g and -
i n t e r p l a n t i n g has been a common p r a c t i c e i n t r o p i c a l c rop
product ion. Under r a i n - f ed c o n d i t i o n s i t p rov ides
s u b s t a n t i a l y i e l d advantages by ensur ing g r e a t e r s t a b i l i t y
o f c rop y i e l d s over d i f f e r e n t seasons, w h i l e guard ing
a g a i n s t c rop f a i l u r e s a r i s i n g f rom such hazards ss pes t
and d isease a t tacks , weed i n f e s t i o n and adverse weather
cond i t i ons . Most farmers would n o t grow tobacco as pure
s tands because they have been used t o mixed cropping.
However, t h e r e i s evidence t h a t i f guaranteed a b e t t e r
c rop combination, many farmers would grow tobacco. I n
o rder t o persuade t h e farmers t o grow tobacco, t he re f
t h e N i g e r i a n Tobacco Company (N.T.C. ) has recommendec
i n t e r p l a n t i n g cassava through tobacco a f t e r t h e 8 t h I
harvest .
The o b j e c t i v e o f t h i s study, therefore, was t o
determine the mutual e f f e c t s of cassava and tobacco
when cassava was i n t e r p l a n t s d a t var ious dates a f t e r
t ransp lan t i ng tobacco.
3
L I T E R A T U R E REVIEW
I n t e r c r o p p i n g , which i n v o l v e s t h e growing o f more
t h a n ona c r o p s i m u l t a n e o u s l y on t h o same p i e c e o f l a n d
( ~ i l l e y , 1 9 7 9 ) , is now r e c o g n i s e d a s a p o t e n t i a l
b e n e f i c i a l s y s t e m of c r o p p r o d u c t i o n . Accord ing t o
W i l l e y (1979) i n t e r c r o p p i n g p r o v i d e s g r e a t e r s t a b i l i t y o f
y i e l d s o v e r d i f f e r e n t s e a s o n s and h i g h e r y i e l d s i n 8 g i v e n
s e a s o n . The obse rved y i o l d a d v a n t a g e s have been a t t r i b u t e d
t o b e t t e r u s e o f g rowth r e s o u r c e s . W i l l e y (1975) s u g g e s t e d
t h a t y i e l d a d v a n t a g e s o c c u r because component c r o p s i n a
m i x t u r e complement e a c h o t h e r and t h e r e b y make b e t t e r
o v e r a l l u s e of g rowth r e s o u r c e s t h a n when t h e y a r e grown
s e p a r a t e l y , i n d i c a t i n g t h a t component c r o p s d o n o t compete
a l i k e f o r e x a c t l y t h o same p r o d u c t i o n r e s o u r c e s . Thus,
i n t e r c r o p c o m p e t i t i o n i s l e s s t h a n i n t r a c r o p c o m p e t i t k m .
Also y i e l d ad*"an tages c o u l d be a t t r i b u t e d t o b e t t e r
c o n t r o l o f weeds ( L i t s i n g e r and Moody 1975; Rao and S h e t t y
1977) , as w a l l as b e t t e r p e s t and d i s e a s e c o n t r o l
(A iye r , 1949 Baker and Norman, 1976) .
I n t e r c r o p p i n g a d v a n t a g e s o c c u r where t h e component
c r o p s d i f f e r , e s p e c i a l l y i n t h e i r g rowth p a t t e r n s , s u c h
a s when t h e i r m a t u r i t y times a r e d i f f e r e n t ( ~ n d r e s 1972;
K r a n t z e e t a l . , 1976; Os i ru and Willey, 1972; W i l l e y and
O s i r u 1972) . Thus, t h e compenent c r o p s make t h e i r major
demands on t h e resources a t d i f f e r e n t t imes. Therefore,
maximis ing i n t e r c r o p p i n g advantages would i n v o l v e rnaxirnising
t h e degree of comp lemen ta r i b between t h e components and
m in im i s i ng i n t e r c r o p compet i t i on .
W i l l e y (1979), however l i s t e d some y i e l d disadvantages
which c o u l d a r i s e from adverse compe t i t i ve e f f e c t s o r
th rough p r a c t i c a l management, such as where t h e component
c rops r e q u i r e d i f f e r e n t sources, t imes and r a t e s o f
f e r t i l i z e r and b i o c i d e app l i ca t i ons .
Determinat ion o f y i e l d advantages i n v o l v e s t h e
comparison o f an i n t e r c r o p p i n g s i t u a t i o n i n which t h e
components a re competing w i t h each o the r aga ins t a
s i t u a t i o n i n which they a re not . Such comparisons take
i n t o account t he compe t i t i ve r e l a t i o n s h i p s , t h e commonest
o f which i s where one componant y i e l d s l e s s and t h e o t h e r
more t han o x p ~ c t e d , The compe t i t i ve a b i l i t y o f the
component crops, i n t h i s case, d i f f e r markedly. W i l l e y
(1979) termed t h i s compensation.
GROWTH CHAHACTERISTICS OF CASSAVA
Cassava o r i g i n a t e d i n Nor th-eas t B r a z i l (Rogers , 1963)
and i s now c u l t i v a t e d i n a l l t r o p i c a l r e g i o n s a f t h e wor ld ,
The p l a n t grows a s a s h r u b w i t h t h e stem r e a c h i n g h e i g h t s
of f o u r metres i n some c u l t i v a r s o r one metre i n dwarf
t y p e s (~nwueme , 1978). The l e n g t h o f t h e i n t e r n o d e s v a r i e s
w i t h c u l t i v a r s and e n v i r o n m e n t a l c o n d i t i o n s , b e i n g s h o r t e r
d u r i n g a d v e r s e t h a n f a v o u r a b l e c o n d i t i o n s (Onwuome, 1978) .
B ranch ing h a b i t o f c a s s a v a , a l s o shows c u l t i v a r d i f f e r e n c e s .
Some c u l t i v a r s d e v e l o p t h r e e b r a n c h e s s i m u l t a n a o u s l y a t a
few c e n t i m o t o r s from t h e ground. Each o f t h o s e b r a n c h e s
t h e n grows and p roduces t h r c c b r a n c h e s a t c . ones, 1959) .
I n a t h e r c u l t i v a r s however, t h e r e is less r e g u l a r i t y i n
b r a n c h i n g h a b i t ,
Tha l o a v c s o f c a s s a v a a r e d e c i d u o u s and s p i r a l l y
a r r a n g e d on t h ~ stem, The l e a f p e t i o l e v a r i e s i n l e n g t h
b u t i s l o n g e r t h a n t h e l amina which i.5 s i m p l e b u t d e e p l y
pa lmate . T h e r e may bo 5-7 l e a f - l o b e s p c r l o a f and e a c h
l e a f measures a b o u t 4-20 c n l o n g and 1-6 cm wide
(Onwueme, 1978) . Cours (1951) q u o t e d by Hunt e t e l . -- (1977) showed t h a t l e a f a r o a o f c a s s o v a i n c r e a s e d r a p i d l y
a t f i r s t and l a t e r d e c l i n e d d u r i n g a d v e r s e p e r i o d s .
Anon ( 1 973 ) , and Cock ( 1 976) howevcr. showed s i m i l a r
r e d u c t i o n i n l e a f a r o a unde r s t a b l e c l i m a t e w h i l e Hunt
et -- a l . (1977) c o n c l u d e d t h a t t h e r e is i n h e r e n t t e n d e n c y
f o r the l e a f area o f cassava t o d e c l i n e i n l a t e r growth
stages.
Jennings (1959) and Anon (1972) showed t h a t s m a l l
l eaves have s h o r t expansion pe r i ods which may bo assoc ia ted
w i t h l onge r l i f e , Deep shading markedly reduces l e a f l i f e
i n cassava, Hence s h o r t e r l e a f - l i f e d u r i n g pe r i ods o f
r a p i d l e a f expansion may r e f l e c t more, mutua l shading
(Hunt e t al,, 1977). Sinha and N a i r (1971) showed t h a t
h i g h l e a f area f o l l o w s l a r g e l e a f number and consequent ly
h i g h l e a f area dura t ion ,
Number o f s to rage r o o t s i s g e n e r a l l y f i x e d e a r l y i n t h e
growth c y c l e o f cassava (Cours, 1951 quoted by Hunt e t a 1 - -'?
1977; O r i o l i , e t ,*t a1 1 9 6 7 ) ~ Beck (1960) r epo r ted s i x months
w h i l e Anon (1973) s t a t e d t h a t t h e number o f s to rage r o o t s is
f i x e d w i t h i n t h e f i r s t t h r e e months a f t e r p l a n t i n g , The
number o f stems pe r p l a n t may a f f e c t t h e numbcr o f s to rage
roo ts , Eny i (1972a, 1972b) showed t h a t p l a n t w i t h more than
one shoot produced more s to rage r o o t s t han p l a n t s w i t h o n l y
one shoot, Cassava e x h i b i t s a phas ic p a r t i t i o n i n g o f d r y
m a t t e r (Loomis and Rapaport, 1977). Dry ma t t e r p a r t i t i o n i n g
t o t h e t u b e r s v a r i e s f rom none a t e a r l y stages o f growth t o
about 80% a t 14 months o f growth, Zandstfa (5979) showed
t h a t t h e h i g h e s t t o t a l d r y ma t t e r production occurred a t
four months, a f t e r v h i c h i t declined; and the highest d r y
7
m a t t c r c o n t e n t s of r o o t s occur red a t s i x months. He a l s o
observed t h a t pe rcen tage d r y m a t t e r accumulated i n t h e
r o o t s i n c r e a s e d r a p i d l y up t o seven months a f t e r p l a n t i n g .
He t h e n concluded t h a t r o o t p roduc t ion does n o t r e a c h a
s u b s t a n t i a l l e v a 1 u n t i l t h r e e months a f t e r p l a n t i n g .
Reac t ion o f Cassava t o o t h e r Crops
Some workers have shown t h a t c a s s a v a i s h i g h l y
s e n s i t i v e t o compe t i t ion a t e a r l y s t a g e s of development
( D o l l and P i e d r a h i t a , 1974; Anon, 1976). During t h i s s t a g e ,
however, l i g h t and o t h e r r e s o u r c e s a r e poor ly u t i l i z e d by
c a s s a v a i n monoculture, hence Anon (1976) sugges ted t h a t
i n t e r c r o p p i n g c a s s a v a wi th a f a s t , ground c o v e r i n g s h o r t
te rm c r o p c o u l d improve t h e c r o p p i n g sys tem's t o t a l y i e l d
pe r h e c t a r e per year .
Cassava a c h i e v e s comple te c o v e r of t h o ground a t t h r e e
t o t h r e e and h a l f months a f t e r p l a n t i n g (Anon, 1976;
Thung and Cock, 1979; flohan Kumar and H r i s h i , 1979).
Because c a s s a v a l a t e r deve lops a c l o s e d canopy which
s u p p r e s s e s t h e growth of t h e o t h e r c r o p s , it is u s u a l l y
p l a n t e d a s a s o l e c r o p o r a s an i n t e r - c r o p (Zands t ra ;
1979). I n t h e l a t e r c a s e it is t h e l a s t c r o p i n t h e
r o t a t i o n (Okigbo, 1971).
Cassava i s i n t e r - p l a n t e d th rough many o t h e r c r o p s ,
such a s maize, rice, taro ( ~ a l o c a s i a e s c u l e n t a ) and sweet
p o t a t o (floreno and Har t , 1979); tobacco ( p o r t 0 e t a 1 1979), - -*,
8
yam okra, melon, T e l f a i r i a occ identa l i s , beans, o i l palm
and rubber (Ezei lo, 1979).
Anon (1978), and Nohan Kumar and H r i s h i (1979) showed
t h a t when cassava was intor-cropped w i t h other crops, the
he igh t o f cassava was increased p r o p o r t i o n a l l y t o the
he igh t o f t he other component, For example, Nohan Kumar
and H r i s h i (1979) showed t h a t t he he igh t o f cassava i n
cassava/maize mix tu re was greater than i n *cassava/bean
mixture. This was probably due t o mutual shading and
compet i t ion f o r l i g h t . Therefore,cnssava he igh t i n mixed
c u l t u r e i s dependent on the growth form o f t he associated
crops.
Time o f I n t e r p l a n t i n q
I n many p a r t s o f the t rop i cs , cassava can be p lan ted
whenever s o i l moisture cond i t ions permit. According t o
E z e i l o (1979), cassava i s p lan tsd a t any t ime du r ing t h e
r a i n y season. I n i n te rc ropp ing systems i n v o l v i n g cassava,
however, i t might be necessary t o ad jus t t h e t imo o f
p l a n t i n g cassava r e l a t i v e t o t h e op t ima l t ime o f p i a n t i n g
a candidate i n te rc rop . However, simultaneous p l a n t i n g o f
cassava and maize has been sham t o g i v e s a t i s f a c t m y y i e l d s -. *
o f cossava (Okigbo, 1977). Anon (1976) showed t h o t
i n te rc rdpp ing a legume (bean) through cassava geve higher
f i n a l . y i e lds o f cassava. Although t h e y i e l d o f in te rc ropped
cassava was l ess than so le crop y i e l d a t 100 days a f t e r
p lan t ing , the y i e l d difference was s i g n i f i c a n t l y reduced a t
180 days a f t e r p lant ing. Leihner (1979) suggested t h a t
,although shor t per iods of compet i t ion f o r l i g h t might n o t
a f fec t cassava y ie lds , prolonged shading by a legume might
reduce cassava y i e l d s considerably. Thus, optimum growth
and subsequent h igh y i e l d s o f cassava would depend upon
t h e a b i l i t y o f tho cassava t o d i sp lay i t s canopy above the
associated crops.
Relay i n te rc ropp ing o f cassava and other annuals has
been suggested. When cassava was i n t e r p l a n t e d through some
annuals l i k e tctbacco (por t0 e t al., 1979; Chiow, 1979),
groundnut, sorghum, long boan (Chew, 1979) s a t i s f a c t o r y
y i o l d advantages werz obtained. However, when these annuals
were i n t e r p l a n t e d through mature stands o f cassava, t h e i r
y i e l d s ware poor. This probably cou ld be a t t r i bu+ed t o
poor soed l ing esbablishmont o f the in te rc rops , s ince i n
matur ing cassava p lo ts , t h e compet i t ion f o r space and
n u t r i e n t s would be too severe f o r normal establishment
and growth of t h e i n t e r p l a n t e d annual.
Zandstra (1 979), compared th ree cassava in te rc ropp ing
pa t te rns w i t h so le crops and showed t h a t t o t a l dry mat ter - - y i a l d was reduced where cassava was mixed w i t h o ther crops,
even though harvest. index o f cassava was h igher f o r a l l
in te rc ropped s i t u a t i o n s than f o r so le crop.
C h a r a c t e r i s t i c s o f . Tobacco Growth
Tobacco o r i g i n a t e d i n c e n t r a l and s o u t h e r n America b u t
is now grown i n most t r o p i c a l a r e a s o f t h e world
( ~ c C o n t s and Wltz , 1967) . Tobacco is a f a s t growing a n n u a l
c r o p which m a t u r e s w i t h i n 100-120 d a y s from t r a n s p l a n t i n g ,
b u t may m a t u r e f a s t e r (80-90 d a y s ) a t h i g h e r mean t e m p e r a t u r e s
(Garne r , 1946) . Tobacco m a i n t a i n s enormous l e a f a r e a , t h e
number and s i z e o f l e a v e s depend on c u l t i v a r and growing
c o n d i t i o n s . Under f o v o u r a b l e c o n d i t i o n s , new r o o t s a p p e a r
w i t h i n f o u r d a y s a f t e r t r a n s p l a n t i n g b u t , no a p p r e c i a b l e
i n c r e a s e i n d r y we igh t of above ground p a r t s o c c u r s , t h e
ma jo r i n c r e a s e o c c u r i n g from t h e 4 t h t o t h e 8 t h week a f t e r
t r a n s p l a n t i n g (IYcCant and Woltz , 1967) .
R e a c t i o n o f Tobacco t o O the r Crop9
T h e r e is v e r y l i t t l e i n f o r m a t i o n on i n t e r c r o p n i n g
s y s t e m i n v o l v i n g tobacco . Chew (1979) , however, r e p o r t e d
t h a t when t o b a c c o was r e l a y - p l a n t e d i n matura c a s s a v a
s t a n d s , t h e y i e l d o f t o b a c c o was v e r y poor . He a t t r i b u t e d
t h i s t o poor s e e d l i n g e s t a b l i s h m e n t ,
The p r e s e n t s t u d y would e v a l u a t o t h o c u r r e n t
recornrnendod p r a c t i c o of i n t e r p l a n k i n g c a s s a v a t h r o u g h t o b a c c o
a f t e r h a r v e s t i n g the e i g h t h l e a f o f t o b a c c o , w h i l e a s s e s s i n g
t h e c o n v e n t i o n a l mixed-cropping p r a c t i c e o f p l a n t i n g a l l c r o p s
i n a m i x t u r e s i rnu l t an , ~ u s l y o r w i t h i n a s h o r t i n t e r v a l ,
MAlERIALS AND METHOD 11
The exper iment was conducted a t t h e F a c u l t y of
A g r i c u l t u r e Teaching and Research farm, U n i v e r s i t y o f
N i g e r i a , Nsukka ( ~ a t i t u d e 06052'~, l o n g i t u d e 07024' and
a l t i t u d e 400m above mean sea. l e v e l ) . '.The t o t a l r a i n f a l l
d u r i n g t h e e x p e r i m e n t a l p e r i o d ( ~ u n e t o October) was
1,249.8rnm and mean maximum and minimum tempsra tu res were
2 8 . 0 ~ ~ and 21 . ~ O C r e s p e c t i v e l y .
Cassava c u l t i v a r 60506 and tobacco v a r i e t y 'Spe igh t '
were used. A l l t h e tobacco s e e d l i n g w e r e t r a n s p l a n t e d
s i m u l t a n e o u s l y a t 4-5 l e a f stage, w h i l e cassava was
i n t e r p l a n t e d t h r o u g h tobacco a t one weekly i n t e r v a l s
s t a r t i n g f r o m t h e d a t e o f t r a n s p l a n t i n g tobacco. The
t r e a t m e n t s c o n s i s t e d o f :
Cassava and tobacco p l a n t e d s imu l taneous ly .
Cassava i n t e r p l a n t e d t h r o u g h tobacco one week
a f t e r t r a n s p l a n t i n g tobacco.
Cassava i n t a r p l a n t e d t h r o u g h tobacco two weeks
a f t e r t r a n s p l a n t i n g tobacco.
Cassava i n t e r p l a n t e d t h r o u g h tobaccn t h r e o week3
a f t e r t r a n s p l a n t i n g tobacco.
Cassava i n t e r p l a n t e d t h r o u g h tobacco a t t h e e i g h t h
l e a f h a r v e s t o f tobacco (i.e. 8 weeks a f t e r
t r a n s p l a n t i n g tobacco ( c o n t r o l ) .
So le cassava p l a n t e d a t each i n t e r p l a n t i n g date.
S o l e tobacco.
There were eleven treatment combinations arrerrped i n a
randomised complete b lock (RCB) design and r e p l i c a t e d fou r
times, The p l o t s i z e was 5m x 5m.
Tobacco seedl ings,raised i n the nursery f o r two months,
were t ransplanted a t a un i fo rm recommended spacing o f 0.5m x
l m o r 20,000 p l a n t s per hectare, Uniform lenghts o f cassava
cu t t i ngs , each 22cm, were p lon tsd i n a s l a n t i n g p o s i t i o n i n an
East-West p o s i t i o n a t a un i fo rm recommended spacing o f
l m x I m o r 10,000 p l a n t s per hectare. Mix tu re popu la t ion was
equiva lent t o 30,000 p l a n t s per hectare.
NTC typo A f e r t i l i z e r mixture conta in ing 12:12:1?:2:
Nitrogen-phosphorous - Potassium - Magnesium oxide ( ~ P ~ m g o )
was app l ied t o tobacco t e n days a f t e r t ransp lan t i ng a t a r a t e
o f 600kg/ha, Cassava a l so received a b lanket a p p l i c a t i o n o f
15:15:15: NPK f e r t i l i z e r a t a r a t e o f 400kg/ha a t f ou r weeks
a f t e r each p lan t ing . Tobacco was sprayed w i t h a mixture o f
284g/ha o r t h i n e (an i n s e c t i c i d e ) and 180g/ha oP Benlate
(Benomyl metmyl l - (butylcarbomyl) 2 benzimidazo/carbamate)
(a fung ic ide) a t weekly i n t e r v a l s s t a r t i n g from 4 weeks a f t e r
t ransp lan t ing ,
Non-destructive sampling was done a t bi-weekly
i n t e r v a l s . Leaf sreo was determined by l i n e a r measurements
i n s i t u . This involved taking t h e product o f t he l eng th
and l a r g e s t breadth o? t he median lobe o f each palmate
l ea f and co r rec t ing f o r the l ea f a rea using the equation
LA = 0 , 4 0 7 b + 11.38 (spencer, l962), where
LA = correc ted leaf a rea , l a = leaF rectangular
a rea x number of leaves, 0.407 and 11.38 a r e regression
cons tants . For tobacco the product of length and
l a r g e s t breadth was corrected t o t r u e l ea f area using the
equation LA = 0.69LW + 4.2 f o r rectangular a rea
exceeding 2,581 cm2 and LA = 0.66LW + 0.02 f o r thoss l e s s
than 2,581 cm2 (Te jiwani - e t -* a 1 1957), where
LA = correc ted l ea f a rea , LW = length x breadth,
4.2, 0.60, 0.65 2nd 0.02 a re regression cons tants .
The number of leaves, p lan t he ight , canopy diameter,
l ength of the 5th intarnode and stem g i r t h were measured
on cassava a t two weekly in t e rva l s . In tobacco, t he
number of leaves, p lan t height and canopy diameter were
me8'red a t the same i n t e r v a l s .
Harvesting 01' tobacco s t a r t e d a t swan weeks and was
completed a t exac t ly 12 weeks (84 days) from date of
t ransplant ing . Fresh and dry weights of leaves, and t o t a l
dry weight were determined a t each harves t and a t f i n a l
harves t t he weights were pooled. Two sample 'harves ts
of cassava were taken a t t h ree months a f t e r p lan t ing and
again a t two months a f t e r f i n a l harves t of tobacco.
Number and f r e s h weight of s torage roo t s , dry ue ights of
stems, leaves , s torage roots anchor roots snd o r i g i n a l
stem cutt ings were determined a t each harvest. Crop
growth rates wero determined using the equation
E = W2 - W1 ( ~ a t s o n , i l 9 5 8 ) , where F = the mean crop I+%? I 42
T2 - TI
growth rote between one and two woeks, W, and W2 = Dry
weight a t Times TI and T2, respectively.
A l l r e su l t s were analysed statistically and compared
using F i shert B Least S igni f icant Difference (F-LSD) a t 5%
l e v e l of probability (Carmer and Swanson, 1973).
15
RESULTS AND DISCUSSION
E f f e c t o f I n t e r p l a n t i n q Cassava on Tobacco
N e i t h e r i n t e r p l a n t i n g n o r t i m e o f i n t e r p l a n t i n g
. cassava e x e r t e d any s i g n i f i c a n t i n f l u e n c e on t h e number
o f leaves, l e a f area, l e a f a rea index, p l a n t h e i g h t and
d r y w e i g h t o f tobacco-leaves. T h i s n o n - s i g n i f i c a n t
e f f e c t o f i n t e r p l a n t i n g cassava suggested t h a t tobacco,
wh ich i s a f a s t g rowing l e a f crop, m i g h t compete
s u c c e s s f u l l y w i th cassava i n mixed s tands p r o v i d e d t h o
tobacco s e e d l i n g s have been c a r e f u l l y s e l e c t e d and
p r o p e r l y t r a n s p l a n t e d . I n t h a t respec t , t h e e f f e c t o f
tobacco on t h e a s s o c i a t e d c r o p becomes more i m p o r t a n t
t h a n t h e e f f e c t of t h e i n t e r p l a n t e d c r o p on t h e tobacco.
V e q e t a t i v e Growth o f Cassava
The number of stems p e r p l a n t was n o t a f f e c t e d by
i n t e r p l a n t i n g n o r t i m e of i n t e r p l a n t i n g . T h i s is t o be
expected s i n c e l e n g t h and o r i e n t a t i o n o f t h e p l a n t e d
c u t t i n g s were un i fo rm. Hunt -- e t a l . (1977) and
Onwueme (1978) had shown t h a t t h e number o f stems
developed by cassava was dependent on t h e l e n g t h and
o r i e n t a t i o n of t h e c u t t i n g s ,
* C
However, i n t e r p l a n t i n g and t i m e o f i n t e r p l a n t i n g
s i g n i f i c a n t l y a f f e c t e d t h e h e i g h t , l e n g t h o f t h e 5 t h
i n t e r n o d e and g i r t h o f cassava stems, Cassava p l a n t e d <
alone was sho r te r than cassava i n t e r p l o n t e d through
tobacco ( ~ i g u r e I ) , w h i l e cassava p lan ted a t t he same
t ime w i t h tobacco was s i g n i f i c a n t l y t a l l e r t han cassava
i n t e r p l a n t e d l a t e r (Table 1). The increases i n t h e
h e i g h t o f i n t e r p l a n t e d cassava appeared t o d e r i v e f rom
s i g n i f i c a n t increases i n the l e n g t h o f t h e in te rnodes
( ~ i g u r e 2) and r e d u c t i o n i n stem g i r t h (F igure 3). Thus,
i n t e r p l a n t e d cassava appeared s p i n d l y and e t i o l a t e d . The
s i g n i f i c a n t d i f f e r e n c e i n p l a n t h e i g h t i n response t o
i n t e r p l a n t i n g and t ime o f i n t e r p l a n t i n g , however, d i d n o t
p e r s i s t a t two months a f t e r ha rves t i ng tobacco. Th i s
suggests t h a t cassava i n t o r p l a n t e d through tobacco cou ld
recover q u i c k l y from e t i o l a t i o n caused by compet i t i on
f rom tobacco.
The e f f e c t o f t i m e o f i n t e r p l a n t i n g on the l e n g t h
o f t h e 5 t h i n te rnode d i d n o t become s i g n i f i c a n t u n t i l
t h e e i g h t h week a f t e r p l a n t i n g a able 2). S i m i l a r l y ,
t he re were no s i g n i f i c a n t d i f f e r e n c e s i n t h e g i r t h o f t h e
5 t h in te rnode u n t i l t h e t e n t h week a f t e r p l a n t i n g
(Table 3). Cassava i n t e r p l a n t e d a t t h e same t ime with
tobacco developed longer and t h i c k e r in te rnodes t han
subsequent i n t e r p l a n t i n g s . The d i f f e r e n c e s i n he ight ,
l e n g t h and g i r t h o f t h e 5 t h in te rnodes o f cassava i n
r e l a t i o n t o t ime o f i n t e r p l a n t i n g cou ld be a t t r i b u t e d t o
g rea te r compe t i t i on f rom f u l l y es tab l i shed tobacco.
1 I 1 1 1
4 6 8 1 0 1 2
S a m p l i n g D a t e ( W e e k s )
- Tobacco/Cossovo lnterplonting
, sole Cassava
FIG. I : E F F E C T O F iNTERPLANTlNG CASSAVA THROUGH TOBACCO ON T H E HEIGHT O F CASSAVA . -
Table I: E f f e c t o f Time o f I n t e r p l a n t i n g Cassava
Through Tobacco on t h e He igh t (cm) o f Cassava
with Time.
Sampling Dates (weeks)
P l a n t i n q Dates (weeks) 4 6 8 I 0 12
3 10.3 22.9 37.3 48.7 60.0
A t 8 t h l e a f Harvest 12.5 27.3 27.4 38.6 50.7
F-LSD 0.05 1.5 3.8 5,6 5.5 6,O
Sampling Dates (Week.)
0 - Tobacco /Carrova Interplantin
FIG. 2 : EFFECT O F INTERPLANTING CASSAVA THROUGH TOBACCO ON THE LENGTH OF 5th. INTERNODE OF CASSAVA
xxw Sole Cossovo
4 6 8 1 0 2
Sampling D a t e ( W e e k s 1
FIG. 3 : EFFECT OF liUTERi>LANTING CASSAiI .4 THROt'GH TCBACCO O N THE GiRTH OF CASS4VA STEM
2 1
Tab le 2: E f f e c t a? Time o f I n t e r p l a n t i n g Cassava
Through Tobacco on The Lang th o f Inkernode (cm)
o f Cassava k i t h Tirne.
Sarnplinq Date (weeks)
P l a n t i n q Da te ( ~ e e k s ) 4 6 8 10 12
A t 0th leaf Harves t 1.5 2.1 2.9 3.0 3.1
F-LSD 0.05 NS NS NS 0.7 1.0
Table 3: E f f e c t o f Time o f I n t e r p l a n t i n g Cassava
Through Tobacco on The Gir th o f Cassava Stems
(cm) With Time.
Samplinq Date (weeks)
P l a n t i n g Date (Weeks) 4 6 8 10 12
A t 8 t h Leaf Harvest 1.8 2.3 2,8 3.9 4.0
F-LSD 0.05 MS If6 6 0.3 0.5
The more s t u r d # y s h o o t s of l a t e r t h a n e a r l i e r i n t e r p l a n t e d
cassava could be a t t r i b u t e d i n p a r t t o reduced c o m p e t i t i o n
f o l l o w i n g t h e h a r v e s t i n g of tobacco which s t a r t e d much
e a r l i e r i n t h e growth c y c l e of l a t e r t h a n e a r l i e r
i n t e r p l a n t e d cassava . T h i s probably caused t h e observed
s l i g h t i n c r e a s e s wi th t ime i n t h e h e i g h t , l e n g t h and
g i r t h of t h e 5 t h i n t e r n o d e i n l a t e r i n t e r p l a n t e d c a s s a v a
and l a r g e i n c r e a s e s i n e a r l i e r i n t e r p l a n t e d cassava .
L a t e r i n t e r p l a n t i n g of cassava th rough tobacco
r e s u l t e d i n dec reased canopy d iamete r of c a s s a v a a able 4)
which cou ld ba dua t o d i f f e r e n c e s i n t ime of i n t e r p l a n t i n g
r a t h e r t h a n i n t e r p l a n t i n g p e r s e .
The h e i g h t of cassava was p o s i t i v e l y and s i g n i f i c a n t J y
c o r r e l a t e d w i t h t h e h e i g h t of tobacco ( r = 0.91) and l e n g t h
o f 5 t h i n t e r n o d e ( r = 0.65), b u t n e g a t i v e l y and
s i g n i f i c a n t l y c o r r e l a t e d w i t h g i r t h of s tem ( r = - 0.74).
There was no s i g n i f i c a n t c o r r e l a t i o n between l e n g t h of
i n t e r n o d a and s tem g i r t h (r = 0.26). P l a n t h e i g h t ,
l e n g t h and g i r t h of 5 t h i n t e r n o d e appeared t o v a r y w i t h
t h e h e i g h t of tobacco. Thus, an i n c r e a s e i n t h e h e i g h t
of tobacco would causo t h e a s s o c i a t e d cassava t o grow
t a l l and s p i n d l y due t o shad ing by tobacco. S i m i l a r
r e s u l t s were o b t a i n e d by Nohan Kumar and H r i s h i (1979),
who showed t h a t t h e h e i g h t of i n t e r c r o p p e d cassava was
Table 4: E f f e c t o f Time o f I n t e r p l a n t i n g Cassava
Through Tobacco an The Canopy Diameter (cm)
o f Cassava with Time.
Samplinq Date (weeks)
P l a n t i n g Date (weeks) 4 6 8 10 12
0 25.5 51.0 72.3 95.0 116.4
1 22.8 42.2 76.6 81.6 90.3
2 22.4 48.3 52.0 62.9 69,7
3 24.3 44.0 56.0 71.1 77,5
A t 8 t h Leaf Harvest 22.3 45.1 50.8 62.2 68,8
F-LSD 0.05 N.S. M.S 6.0 7.4 9.1
p r o p o r t i o n a l t o t h e h e i g h t s of t h e a s s o c i a t e d c rop . Thus,
c a s s a v a a t t a i n e d g r e a t e r h e i g h t i n cassava /maize t h a n i n
ca s sava /bean m i x t u r e . No s i g n i f i c a n t i n t e r a c t i o n
between i n t e r p l a n t i n g and time of i n t e r p l a n t i n g was
o b s e r v e d a t a l l s ampl ing d a t e s .
Leaf Area Development i n Cassava
The number of l e a v e s d i d n o t d i f f e r s i g n i f i c a n t l y
i n t h e s o l e and i n t e r p l n n t e d c a s s a v a . Time o f
i n t e r p l a n t i n g , however, s i g n i f i c a n t l y a f f e c t e d t h e number
o f l e a v e s deve loped by c a s s a v a ( T a b l e 5). E a r l i e r
i n t e r p l o n t e d c a s s a v a , namely t h o s e p l a n t e d a t t h e
same time and one week a f t e r t r a n s p l a n t i n g t o b a c c o ,
p roduced more l e a v e s t h a n t h o s e p l a n t e d a f t e r h a r v e s t i n g
t h e e i g h t h l e a f o f t obacco . The re was a t e n d e n c y f o r
c a s s a v a l e a f f o r m a t i o n t o be r e p r e s s e d by t h e p r e s e n c e of
t o b a c c o l e a v e s . A f t e r e v e r y t o b a c c o h a r v e s t t h e r e was
a f l u s h of new l e a v e s i n t h e e a r l y p l a n t e d c a s s a v a ,
L a t e r i n t e r p l a n t e d c a s s a v a produced l e a v e s a t a s l o w e r
ra te t h a n t h e e a r l i e r p l a n t e d c o u n t e r p a r t s .
I n t e r p l a n t i n g d i d n o t e x e r t a n y significant e f f e c t
on t h e l e a f a r e a and l o a f area i n d e x OF cassava,
Z a n d s t r a (1979) showed t h a t l e a f area o f u n d e r s t o r e y
c r o p s was s i g n i f i c a n t l y reduced by i n t e r c r o p p i n g , I n
t h i s e x p e r i m e n t , s e q u e n t i a l h a r v e s t i n g o f ma tu re t o b a c c o
2 6
Table 5: E f f e c t o f Time I n t e r p l a n t i n g Cassava Through
Tobacco on The Number o f Cassava Leaves With
Time,
S a m p P i n ~ Date (weeks) 2 Months A f t e r
P l a n t i n g Date(weeks) 4 6 8 10 12 Tobacco Harvest
0 21. 40 62 69 93 100
A t 0 t h Leaf Harvest 9 16 24 37 50 6 3
F-LSD 0.05 2.7 4.5 6e4 8e3 10.3 17.0
27
leaves s t a r t e d when cassava was o n l y 0-7 weeks o ld . Th is
reduced t he shade o f tobacco on t he under s t o r e y cassava
a t a t ime when heavy shading has been shown t a be very
c r i t i c a l t o cassava ( D o l l and P ieddrah i ta , 1974),
Time o f i n t e r p l a n t i n g , however, s i g n i f i c a n t l y
a f fec ted l e a f area (F igure 4) and l e a f area index (LAI)
( ~ i g u r e 5 ) . Both l e a f area and l e a f area index decreased
as t ime o f i n t e r p l a n t i n g was delayed, Leaf area i ndex
o f a l l t reatments cont inued t o ioc rease d u r i n g t h e p e r i o d
o f s t u d i e s except t h a t o f the cassava i n t e r p l a n t e d one
week a f t e r t r a n s p l a n t i n g tobacco, t h e l e a f area index o f
which peaked a t 1,65 a t twe lve weeks a f t e r p l a n t i n g
(F igure 5). Th is cou ld be due t o sampling e r ro r . Anon
(1976) r epo r ted a peak l e a f area index o f 3 a t 4 months
a f t e r p l a n t i n g . F i gu re 6 shows t h a t t he r a t e o f i nc rease
i n LA1 inc reased r a p i d l y i n t he f i r s t t h r e e months and
then dec l i ned sharp ly , Thus, i n t e r p l a n t i n g cassava
through tobacco delayed t he t ime t o a t t a i n t h e peak LA1
p a r t i c u l a r l y when i n t o r p l a n t e d f rom t h r e e weeks a f t e r
t r a n s p l a n t i n g tobacco.
LA1 of cassava p l an ted a t t h e same t ime w i t h tobacco
inc reased a t t he h i ghes t r a te , w h i l e LA1 o f cassava
i n t e r p l a n t e d a t t h e 8 t h l e a f ha rves t o f tobacco inc reased
a t t h e s lowest r a t e .
* Week After Transplanting Tobacco
+- O Week / / - I
0 0 2 Weeks
4 6 $ ib lh 114 16 lb Z!O
Sompling Date ( Weeks
FIG. 4 : EFFECT OF TIME OF INTERPLANTING CASSAVA THROUGH TOBACCO ON THE LEAF AREA ( L A ) OF CASSAVA.
Week After Transplanting Tobaccc - 0 Week - I Weeks - 2 Weeks
.+--- 4 3 Weeks
*---.-a At 8!h. lea? harvest
4 6 8 10 12 14 16 18 20
Sampling D a l e (Weeks )
FIG. 5 : EFFECT OF TIME OF INTERPLANTWG CASSAVA THROUGH TOBACCO ON THE LEAF AREA INDEX ( L A I ) OF CASSAVA
Week After Transplanting Tobacco
+-- - -q 3 I'
D- - - --4 At 8 t h . ieaf harvest
I I I 1 6 8 10 12 2 Months after tobacco
harvest Sampling Date (Weeks)
FIG. 6 : EFFECT OF TIME OF INTERPLANTING CASSAVA THROUGH TOBACCO ON
THE RATE OF lNCREASE IN LEAF AREA INDEX ( L A 1 ) T -
Top Growth Rete of Cassava a t Two Months A f t e r H a r v e s t i n q
Tobacco
Two months a f t e r t h e f i n a l h a r v e s t of t o b a c c o , t h e
, t o p growth r a t e of i n t e r p l a n t e d c a s s a v a was 25% g r e a t e r
t h a n t h a t of s o l e c a s s a v a . T h i s s u g g e s t s a s t r o n g
t endency by c a s s a v a t o r e c o v e r from c o m p e t i t i o n a f t e r
h a r v e s t i n g t h e a s s o c i a t e d tobacco . The f a v o u r a b l e
e f f e c t s of e a r l y i n t e r p l a n t i n g a p p e a r e d t o p e r s i s t even
a f t e r h a r v e s t i n g tobacco . Hence, growth r a t e o f c a s s a v a
a f t e r t o b a c c o had been c o m p l e t e l y h a r v e s t e d was l e s s i n
l a t e r , t h a n i n e a r l i e r i n t e r p l a n t e d c a s s a v a . Top growth
rate was 18.39 mo2 weokg' when c a s s a v a was p l a n t e d a t t h e
same time a s t obacco . T h i s d i m i n i s h e d by 38.9, 41.1,
45.6 and 65.6 p e r c e n t when c a s s a v a was i n t e r p l a n t e d one ,
two and t h r e e weeks a f t e r t r a n s p l a n t i n g t o b a c c o
8 t h l e a f h a r v e s t , r e s p e c t i v e l y .
Number of S t o r a q e Roots
I n t e r p l a n t i n g and time of i n t e r p l a n t i n g d i d n o t
s i g n i f i c a n t l y a f f e c t t h e number o f s t o r a g e r o o t s o f
c a s s a v a a t t h r e e months a f t e r p l a n t i n g n o r a t two months
a f t e r h a r v e s t i n g t o b a c c o , T h i s s u g g e s t s t h a t t h e number
of s t o r a g e r o o t s o f c a s s a v a i s de te rmined m o s t l y by t h e
g e n e t i c c o n s t i t u t i o n r a t h e r t h a n t h e growing c o n d i t i o n s
o f t h e c r o p (Hunt e t a l . , 1977) .
32
F r e s h Weiqht o f Roots
R e s u l t s p resen ted i n t a b l e 6 show t h a t b o t h
i n t e r p l a n t i n g and t i m e o f i n t e r p l a n t i n g s i g n i f i c a n t l y
a f f e c t e d t h e f r e s h we igh t o f s t o r a g e r o o t s a t t h r e e
months a f t e r p l a n t i n g . Two months a f t e r h a r v e s t i n g
tobacco, however, o n l y t i m e o f i n t e r p l a n t i n g a f f e c t e d
f r e s h we ight o f s to rage r o o t s s i g n i f i c a n t l y . A t t h r e e
months a f t e r p l a n t i n g , t h e f r e s h we igh t o f s t o r a g e
r o o t s was 62.5 p e r c e n t g r e a t e r i n t h e s o l e t h a n i n t h e
i n t e r p l a n t e d cassava. A t two months a f t a r h a r v e s t i n g
tobacco, however, t h e d i f f e r e n c e was o n l y 3.8 p e r c e n t
(Tab le 6). T h i s f u r t h e r r e f l e c t s t h e r a p i d t o p growth
o f cassava a f t e r h a r v e s t i n g tobacco and f u r t h e r suggests
t h e a b i l i t y o f cassava t o r e c o v e r f o l l o w i n g t h e
c o m p l e t i o n o f tobacco ha rves t .
F resh we igh t o f s t o r a g e r o o t s was g r e a t e r when
cassava was p l a n t e d s i m u l t a n e o u s l y w i t h tobacco t h a n
when i n t e r p l a n t e d a t any t i m e a f t e r t r a n s p l a n t i n g tobacco
( table 7). A t t h r e e months a f t e r p l a n t i n g t h e f r e s h
w e i g h t o f s t o r a g e r o o t s when cassava was p l a n t e d a t t h e
same t i m e wi th tobacco was 2 0 0 g / ~ l a n t . T h i s was reduced
by 20, 60, 70 and 80 p e r c e n t when cassava was
i n t e r p l a n t e d one, two, t h r e e and e i g h t weeks, a f t e r
t r a n s p l a n t i n g tobacco r e s p e c t i v e l y . A t two months
a f t e r h a r v e s t i n g tobacco, however, t h e f r e s h w e i g h t o f
s t o r a g e r o o t s was 970g/plant f o r s imul taneous p l a n t i n g ,
Table 6: E f f e c t o f I n t e r p l a n t i n g Cassava Through
Tobacco on The Fresh Weight (g /p lant ) o f
Cassava Storage Roots A t 3 Months A f t e r
P l a n t i n g And 2 Months A f t e r F i n a l Harvest
o f Tobacco.
3 Months A f t e r 2 Months A f t e r F i n a l P l a n t i n q Hervest o f Tobacco
Sole 130 530
~assava /~obacco I n t e r p l a n t
F-LSD 0.05 48.0 N.S
Table 7: E f f e c t o f Time o f I n t e r p l a n t i n g Cassava
Through Tobacco on The Fresh Weight ( d p l a n t )
of Cassava Storage Roots A t 3 Months A f t e r
P l a n t i n g and A t 2 Months A f t e r F i n a l Harvest
o f Tobacco.
3 Months A f t e r 2 Months After F i n a l P l a n t i n q Date (Weeks) P l a n t i n q Harvest o f Tobacco
A t 8 t h Leaf Harvest 40 180
F-LSD 0.05 30.6 210
and t h i s decreased by 34.0, 55.7, 59.8 and 81.4 percent
whon cassava was p lanted one, two, th ree and e i g h t weeks,
a f t e r t ransp lan t i ng tobacco respec t ive ly . Thus, t he
advantage o f e a r l i e r i n t e r p l a n t i n g pe rs i s ted even a f t e r
harves t ing tobacco. The poor y i e l d o f storage r o o t s
obtained from cassava i n t e r p l a n t e d a f t e r t he e i g h t l e a f
harvest, t h a t i s e i g h t weeks a f t e r t ransp lan t i ng
tobacco, was a d i r e c t consequence o f i t s poor growth and
development. Chew (1979) and Por t0 -- e t a l . (1979)
had repor ted t h a t cassava gave s a t i s f a c t o r y y i e l d s when
p lanted i n mature stands o f tobacco, al though these authors
d i d n o t q u a n t i f y t h e i r resu l t s . The performance o f t h e
crop a t t h i s t i m e may no t be a good i n d i c a t o r o f f i n a l
y i e l d bu t i f the adverse e f f e c t o f l a t e r i n t e r p l a n t i n g
pe rs i s t s , i n t e r p l a n t i n g cassava through tobacco a f t e r
harves t ing the e igh th l e a f would l i k e l y reduce f i n a l
y i e l d o f storage roots.
Dry Matter Yie lds
There was no s i g n i f i c a n t response t o i n t e r p l a n t i n g
i n t h e t o t a l d ry mat ter y i e l d o f cassava a t bo th three
months a f t e r p l a n t i n g and two months a f t e r tobacco
harvest. The t o t a l d ry matter y i e l d o f i n t e r p l a n t e d
cassava was on ly 10 2er cent l e s s than t h a t o f so le
cassava. Zandstra (1979) had repor ted s i m i l a r a f f e c t s o f
i n t e r p l a n t i n g on t o t a l d r y m a t t e r y i e l d o f c a s s a v a .
Watson (1956) p o i n t e d o u t t h a t t h e main f a c t o r s l e a d i n g
t o v e r y g r e a t d i f f e r e n c e s i n d r y m a t t e r a c c u m u l a t i o n i n
p l a n t s i s t h e r a t e o f e x t e n s i o n i n leaf s u r f a c e , which
i n c l u d e s s i z e of i n d i v i d u a l l e a v e s , and r a t e of p r o d u c t i o n
o f new l e a v e s . As r e p o r t e d e a r l i e r , b o t h l e a f a r e a and
r a t e o f p r o d u c t i o n o f new l e a v e s were n o t s i g n i f i c a n t l y
d i f f e r e n t i n s o l e and i n t e r p l a n t e d c a s s a v a .
R e s u l t s p r e s e n t e d i n t a b l e 8 show t h a t i n t e r p l a n t i n g
d i d n o t s i g n i f i c a n t l y a f f e c t t h e d r y matter c o n t e n t s o f
t h e s t e m s and p l a n t e d c u t t i n g s a t t h r e e months, and l a t e r
s a m p l i n g d a t e . A t t h r e e months a f t e r p l a n t i n g more d r y
m a t t e r was accumula t ed i n t h e l e a v e s (+27%) and s t o r a g e
r o o t s (+53%), i n s o l e t h a n i n t h e i n t e r p l a n t e d c a s s a v a ,
These d i f f e r e n c e s were n o t , however, obse rved a t two
months a f t e r h a r v e s t i n g tobacco .
R e s u l t s p r e s e n t e d i n T a b l e s 9 and 10 show t h a t time
o f i n t e r p l a n t i n g s i g n i f i c a n t l y a f f e c t e d b o t h t o t a l d r y
matter y i e l d and d r y matter p a r t i t i o n e d i n t o stems
l e a v e s , s t o r a g e r o o t s and p l a n t e d c u t t i n g s . I n a l l
i n s t a n c e s e a r l i e r i n t e r p l a n t i n g r e s u l t e d i n h i g h e r d r y
matter y i e l d a t b o t h s ampl ing d a t e s . The r e s u l t s a l s o
show t h a t d r y w e i g h t s of s t o r a g e r o o t s and p l a n t e d c u t t i n g s
were sti l l i n c r e a s i r 3 a t t h e 2 0 t h week a f t e r p l a n t i n g ,
Table 8: E f f e c t o f I n t e r p l a n t i n g on The D i s t r i b u t i o n
of Dry f la t te r Among Various Organs o f Cassava
Three Months A f t e r P lant ing.
(q/p&ant)
Storage T o t a l Stem Leaves Root ;.Cuthinqs
Sole cassava 166.8 28.9 69.7 41.7 45.6
~assava/~obacco
I n t e r p l a n t 149.3 31.5 50.8 19.6 46.6
F-LSD 0.05 NbS, N.Sb 13.8 14.3 0.6
Table 9: E f f e c t o f Time o f I n t e r p l a n t i n g on The
D i s t r i b u t i o n of Dry f l a t t e r Among Various
Organs o f Cassava A t Three Months A f t e r
P lant ing.
(s/plant)
P l a n t i n g Date Storage
( ~ e e k a ) Total Stern Leaves Roots Cut t ings
A t 8 t h l e a f Harvest 109.2 18.4 38.8 8 7 47.3
F-LSD 0.05 24.3 7,9 8.7 9.0 7m1
Table 10: E f f e c t o f Time o f I n t e r p l a n t i n g on The
D i s t r i b u t i o n o f Dry Mat ter Among Various Orgens
o f Cassava Two Months A f t e r F i n a l Tobacco
Harvest .
(q/plant)
P lan t i ng Date Storage
(Weeks) T o t a l Stem Leaves Roots Cu t t i nss
0 686.0 169.8 132.7 304.1 98,5
1 350.6 138.7 73.4 246.8 75.7
2 322.0 62.2 60.7 126.4 72.7
A t 8 t h l e a f
harvest 166.3 34.2 43.6 46.4 56.1
F-LSD 0 .05 48.5 9.5 10.0 38 .7 7 5
Ezedinma -- e t a l . (1981) had repor ted t h a t y i e l d o f storage
r o o t s and o l d stock (planted cu t t i ngs ) increased s t e a d i l y
up t o the 12 th month and then decl ined - a r e s u l t uh ich
suggests t h a t t he p lanted c u t t i n g s could be an
a l t e r n a t i v e s ink f o r assimi lates.
A t th ree months a f t e r p lant ing, cassava had
accumulated l i t t l e d ry mat ter i n tho storage r o o t s
compared w i t h the shoots. But a t two months a f t e r f i n a l
harvest o f tobacco more d ry matter had accumulated i n
the r o o t s than i n the shoots. This supports the phasic
S p e r t i t i o n i n g of d ry matter i n cassava reported* Loomis '?
and Rapaport (1977). Anon (1976) had pointed out t h a t
a h i g h LA1 would r e s u l t i n l i t t l e r o o t weight increase,
as a l l ava i l ab le carbohydrates would be d i ve r ted t o t h e
shoot. A low LAI, on the other hand, would cause more
dry matter t o accumulate i n the storage roo ts . Leaf
area index dur ing the f i r s t three months o f growth
increased r a p i d l y but a t two months a f t e r f i n a l harvest
o f tobacco, LA1 had s t a r t e d t o dec l ine
These events suggest balance o f growth
and roo t .
There were no r e a l d i f f e rences i n
sharp ly (Figure 6).
between t'he shoot
t he propor,kion o f
the d ry weight of ?he var ious organs o f so le and i n t e r p l a n t e d
cassava ( ~ a b l e s 11 and 12). Time o f in te rp lank ing , however,
appeared t o in f luence the p ropor t i on o f d ry weight i n these
4 1
Table 11: E f f e c t o f i n t a r p l a n t i n g on The Percentage o f
Dry f l a t t e r i n Various Organs o f Cassava Three
Months A f t e r P lant ing.
Percentage Dry Mat ter Storage
T o t a l Stem Leaves Roots Cut t inqs
Sole cassava 166.6 16.4 35.5 17.8 30,6
Tobacco/~assava 5
.- I n t e r p l a n t 149.3 19,4 34.0 14.8 34.8
Table 12: E f f e c t o f I n t o r p l a n t i n g on t h o Percen tage o f
Dry Mat ter i n Var ious Organs of C ~ s s a v a Two
Months A f t e r Fino1 Harves t of Tobacco.
Pe rcen tage Dry f l a t t e r
S t o r a g e T o t a l Stem Leaves Roots C u t t i n g s
S o l e Cassava 384.0 21.1 20.2 41.9 22,5
~ o b a c c o / ~ a s s a v a
I n t e r p l a n t 345.5 23.7 22.7 42.0 23.4
43
o r g a n s a t t h r e e months a f t e r t o b a c c o h a r v e s t ( T a b l e 13),
and a t 2 months a f t e r f i n a l t o b a c c o h a r v u s t ( T a b l e 14).
P e r c e n t a g e o f d r y rnn t tor i n stem, l e a f and s t o r a g e r o o t s
decreased w i t h l a t e r i n t e r p l a n t i n g , w h i l e p e r c e n t a g e o f
d r y m a t t e r i n t h e c u t t i n g i n c r e a s e d w i t h l a t e r
i n t e r p l e n t i n g . Thus, growing c a s s a v a t h r o u g h t o b a c c o
might n o t a f f e c t d r y m a t t e r p a r t i t i o n i n g i n c a s s a v a , b u t
t h i s would depend on t h e time o f i n t e r p l a n t i n g c a s s a v a ,
I n t e r p l a n t i n g c a s s a v a much l a t e r a f t e r t r a n s p l a n t i n g
t o b a c c o , namely t h r e e weeks t o o i g h t weeks ( i .e , a t e i g h t h
l e a f h a r v e s t ) would c a u s e most of t h e assimilates t o be
t e i z w b y t h e p l a n t e d c u t t i n g s t h u s r e s u l t i n g i n l ower d r y
m a t t e r p a r t i t i o n i i n c j t o t h o s t o r a g o r o o t s .
R e s u l t s p r e s e n t e d i n t a b l o s 10-13 show c l e a r l y a n
e v i d e n c e o f p h a s i c deployement o f d r y m a t t s r i n c a s s a v a .
Whereas a g r e a t e r p r o p o r t i o n o f t h e t o t a l d r y m a t t e r was
dep loyed i n s h o o t a t t h r e e months a f t e r p l a n t i n g , t h e r e
was s p e c t a c u l a r b u i l d up o f d r y m a t t e r i n t h e r o o t s a t
two months a f t e r f i n a l h a r v e s t of t o b e c c o .
The number of l e a v e s was n o t s i g n i f i c a n t l y c o r r e l a t e d
w i t h number o f r o o t s b u t was s i g n i f i c a n t l y and p o s i t i v e l y
c o r r e l a t e d w i t h t h e f r e s h w e i g h t o f s t o r a g e r o o t s
( r = 0.65). Thus, p l a n t s w i t h more l e a v e s had h i g h e r
y i e l d o f s t o r a g e r o o t s . Top growth r a t e o f c a s s a v a a t
44
Table 13: E f f e c t o f Time ~f I n t e r p l a n t i n g on the
Percentage o f Dry B a t t e r i n Various Organs
of Cassava Three Months A f t e r P lant ing.
Percentnqe Dry f l a t t e r
P l a n t i n g Date Storage (weeks) T o t a l Stem Leaves Roots Cut t inqs
0 264 22.0 39.5 24,O 15,O
A t 6 t h leaf Harvest 109.2 15.5 32.0 0.7 45.0
45
Table 14: E f f e c t o f Time o f I n t e r p l a n t i n g on The
Percentage o f Dry Ma t t e r i n Var ious Organs
of Cassava Two Months A f t e r F i n a l Harvest
o f Tobacco. . .
Percentaqe Dry Ma t t e r
Mean T o t a l Storage Dry w t . Stem Leaves Roots C u t t i n q s
A t 8 t h l e a f Harvest 166.3 20.6 26.2 28,O 33.8
two months a f t e r h a r v e s t i n g t o b a c c o was n o t c o r r e l a t e d
w i t h number o f s t o r a g e r o o t s . T h i s c o n f i r m s t h a t t h e
number o f s t o r a g e r o o t s t o be deve loped is g e n e t i c a l l y
c o n t r o l l e d . However, t o p growth r a t e was p o s i t i v e l y
c o r r e l a t e d w i t h f r e s h we igh t o f s t o r a g e r o o t s . When
c a s s a v a was i n t e r p l a n t e d t h r o u g h t o b a c c o a t d i f f e r e n t
d a t e s , t h e f r e s h w e i g h t o f s t o r a g e r o o t s d e c r e a s e d w i t h
la ter i n t e r p l a n t i n g . S i m i l a r l y t o p growth r a t e o f
c a s s a v a a t two months a f t e r f i n a l t o b a c c o h a r v e s t
d e c r e a s e d w i t h l a t e r i n t e r p l a n t i n g .
Number o f s t o r a g e r o o t s was s i g n i f i c a n t l y and
p o s i t i v e l y c o r r e l a t e d w i t h t h e y i e l d of s t o r a g e r o o t s
( r = 0,53), b u t g r e a t e r number of r o o t s p e r p l a n t t e n d e d
t o d e c r e a s e t h e w e i g h t o f i n d i v i d u a l r o o t s . The d r y
w e i g h t o f s t o r a g e r o o t s was p o s i t i v e l y and s i g n i f i c a n t l y
c o r r e l a t e d w i t h t h e t o t a l d r y m a t t e r y i e l d o f c a s s a v a ,
Boerboom (1978) and Wi l l i ams (1974) had r e p o r t e d s i m i l a r
r e l a t i o n s h i p between d r y w e i g h t o f s t o r a g e r o o t s and t o t a l
d r y we igh t . T h i s s u g g e s t s t h a t b u l k i n g r a t e had k e p t pace
w i t h t h e c r o p growth r a t e (Hoerboom, 1978) o r t h a t g r e a t e r
d r y m a t t e r c o u l d be a n e f f e c t o f s t o r a g e r o o t s on t h e
l e a v o s , s i n c e g r e a t e r a c t i v i t y may l e a d t o a f a s t e r ra te
of p h o t o s y n t h e s i s , (Wi l l i ams 1974) . The f i r s t o f t h e two
e x p l a n a t i o n s was more e v i d e n t i n t h i s c a s e s i n c e t r e a t m e n t s
w i t h h i g h e r t o p growth r a t e accumula t ed h i g h e r d r y matter
i n t h e s t o r a g e r o o t s .
I t was a l s o o b s e r v e d t h a t t o t a l d r y w e i g h t was
p o s i t i v e l y and s i g n i f i c a n t l y c o r r e l a t e d w i t h d r y w e i g h t s
o f stems ( r = 0.89). O t h e r worke r s ( ~ i g h o l t , 1935
q u o t e d by Boerboom,l978; Cours , 1951 quo ted by
Boerboorn, 1978 ; Hunt, 1974) have r e p o r t e d similar
r e l a t i o n s h i p s between s t e m s and l e a v e s w i t h t o t a l d r y
we igh t . Thus, t h e d i s t r i b u t i o n o f t o t a l d r y m a t t e r
o v e r stems, l e a v e s , and s t o r a g e r o o t s is uni form.
SUMMARY AND CONCLUSION
Growth and y i e l d o f tobacco were n o t a f f e c t e d by
i n t e r p l a n t i n g nor by t i m e o f i n t e r p l a n t i n g cassava
through tobacco.
I n t e r p l a n t i n g o f cassava through tobacco increased
p l a n t h e i g h t and l e n g t h o f t h e i n te rnode bu t decreased
t h e g i r t h o f cassava stems. Delayed i n t e r p l a n t i n g
reduced p l a n t he ight , l e n g t h o f i n t e rnodes and stem
g i r t h o f cassava,
Number o f leaves, l e a f area and l e a f area index were
s t a t i s t i c a l l y s i m i l a r i n s o l e and i n t e r p l a n t e d cassava
b u t l a t e r i n t e r p l a n t i n g tended t o reduce these parameters.
A t t h ree months a f t e r p l an t i ng , f r e s h weight o f
s to rage r o o t s was l e s s i n i n t e r p l a n t e d t han s o l s cassava,
b u t t h i s d i f f e r e n c e disappeared s h o r t l y a f t e r f i n a l
tobacco harvest , The r e d u c t i o n i n f r e s h weight o f
cassava w i t h delayed i n t e r p l a n t i n g , however, p e r s i s t e d
even a f t e r tobacco had been complete ly harvest ,
T o t a l d r y ma t t e r produced by cassava decreased
w i t h delayed i n t e r p l a n t i n g , b u t was no t a f f ec ted by
i n t e r p l a n t i n g . Dry ma t t e r p a r t i t i o n i n g t o v a r i o u s
organs o f cassava decreased w i t h l a t e r i n t e r p l a n t i n g ,
There was lower d r y ma t t e r i n t h e s torage r o o t s o f
i n t e r p l a n t e d cassava a t t h ree months a f t e r p l an t i ng , bu t
t h i s d i f f e r e n c e disappeared two months a f t e r ha rves t i ng
tobacco,
Cassava c o u l d be grown w i t h t o b a c c o i n mixed s t a n d s
w i t h s u b s t a n t i a l a d v a n t a g e p rov ided t h e two c r o p s a r e
grown s i m u l t a n e n u s l y , Cassava i n t e r p l a n t e d n o t l a t e r
t h a n one week a f t e r t r a n s p l a n t i n g t o b a c c o would produce
s i m i l a r r e s u l t s . However, more wcrk is r e q u i r e d t o
d e t e r m i n e t h e r e a c t i o n s of c a s s a v a and t o b a c c o when t h e
fo rmer i s p l a n t e d b e f o r e t r a n s p l a n t i n g t h e l a t t e r .
REFERENCES
Aiyer , A. K . Y .N . ( 1949) : Mixed c ropp ing i n I n d i a ,
I n d i a n 3. Agric. S c i . - 19, 439-543.
Andrews, D, J (1972) : I n t e r c r o p p i n g wi th Sorghum
i n N i g e r i a , Exp, Aqric. 8, 139-150.
Anon ( 1 972) : Cassava Prosram Review conference
p r o c e e d i a q s , Centro I n t e r n a t i o n a l de A q r i c u l t u r a
t r o p i c a l (CIAT) . C a l i Columbia.
Anon, (1973) : Annual Report. Centro I n t e r n a t i o n a l
d e A q r i c u l t u r a Trop iza l . C a l i Columbia pp. 60-118.
Anon. (1976): Cassava Produc t ion System Proqram Annual
Report . CIAT p. 1-12.
Anon. (1976): Annual Report f u r 1977, Centro
I n t e r n a t i o n a l de A q r i c u l t u r a T r o p i c s l . C a l i
Columbia (cIAT) 49-50.
Baker, E.F. I. and Norman, U.N. (1975) : Cropp!ng
Systems i n Northcrn Niger i a . J1n) Proceedinqs
of C r o m i n a Svstems Worksho~ IRU. Los Eianos, 3 ~ 4 - 6 1 .
Beck, B,D.A. (1960) : Cassava t r i a l s on Moor P l a n t a t i o n .
Report oP t h e Department of A q r i c u l t u r e Research,
N i g e r i a 1958-1959, pp.11.
Boerboom, B.W.S. (1978) : A model of d r y mat to r
d i s t r i b u t i o n i n cassava ( ~ a n i h o t e scu len ta Cran tz ) . Neth, J. Aqric, S c i . 26(3), 267-277. -
10. Carmer, S.G. and Swanson, M.R. (1973): An
evaluat ion of Ten Pairwise mult iple comparison
procedure by Monte Callo Method.
J . Amer. S t a t . Assoc. - 68(341), 66-76.
1 1. Chew, W. Y . (1979) : Cassava intercropping pa t t e rns and
p rac t i ces i n Malaysia. (1n) Intercroppinq w i t h
Cassava. - Proceedinqs of An In te rna t iona l Workshoe
held a t Trivandrum. India 27 Nov. - Dec. 1978,
43-48.
12. Cock, J.H. (1976) : Charac te r i s t i c s of high yielding
cassava v a r i e t i e s , Exp. Aqric. - 12, 135-143.
13. Doll, J.D. and Piedrahi ta , W. (1974): Rargen d e
Se lec t iv i l ad de var ios herbicides en Layuea.
Revista Cornalfi. I ? ( I ) , 14-19.
14. Enyi, B.A.C. (1972 a) : The e f f e c t of spacing on growth,
development and y ie ld of simple and mult iple shoot
p lan t s of cassava (Ranihot e s c u l m t a ~ r a n t z ) , I. Root tuber yield and a t t r i b u t e s . East African
Aqr icul tura l and Forestry Journal. - 38, 27-54.
15. Enyi, B.A.C. (1972b): Effect of shoot number and time
of plant ing on growth development and y ie ld of
cassava (Ranihot esculenta ~ r a n t z ) , Hort . Sci. 47,
157-466.
16. Ezedinma, F .O.C., I b o O.G. and Onwuchuruba, A. I. (1981) :
Performance o f cassava i n r e l a t i o n t o t ime o f p l a n t i n g
and harves t ing . (1n) T r o p i c a l Root Crops: Research
S t r a t e g i e s For The 1980s. Proceedings o f The F i r s t
T r i e n n i a l Root Crops Symposium o f The I n t e r n a t i o n a l
Soc ie ty For T r o p i c a l Root Crops - A f r i c a Branch.
8 - 12 Seet. - 1980, Ibadan - N ige r i a . 111 - 115.
17. Eze i lo , W.N.O. (1979) : I n t e r c r o p p i n g with cassava i n
Af r ica . (1n) I n t e r c r o p p i n s w i t h Cassava Proceedinqs
o f An I n t e r n a t i o n a l Workshop h e l d a t Trivandrum.
I n d i a 27 Nov. 1 Oec. 1978, 49-56.
18. Garner, W.W. (1946) : The p roduc t i on o f Tobacco. The
B lecks ton Company, Toronto, pp. 516.
19. Hunt, L.A. (1974): Growth phys io logy o f f lanihot . I n t e r n a l
Report, Department of Crop Science, U n i v e r s i t w
Guelph. Guelph, On ta r i o Canada.
20. Hunt, L.A.: Wholey, D.W. and Cock, J.H. (1977): Growth
phys io l ogy of cassava ( f l an iho t escu len ta ~ r a n t z ) . F i e l d Crop Abat. 30, (2) 77-91, -
21. Jennings, D.L. (1959): A u s e f u l pa ren t f o r cassava
breeding, E u p y t i c a . 8. 157-162.
22. Jones, W.O. (1959) : Manioc i n Af r ica . S tan fo rd U n i v e r s i t y
Press - Stanford. 315 pp.
23, Krantze, B.A.; Virmani, S.M.: Sardar, S, and Ra0,M.R.
(1976) 1 I n t e r c r o p p i n q f o r increased and more s t a b l e
a g r i c u l t u r a l p roduc t ion i n t h e semi-ar id t r o p i c s .
(1n) Symposium on I n te r c ropp inq i n Semi-Arid Areas.
( ~ r o c a e d i n ~ s ) . Morogoro, Tanzania 10-12 May.
24. Leihnsr, D. E. (1 979) : Agronomic cons ide ra t i ons i n
cassava i n t e r c r o p p i n g research. (In)
I n t e r c r o p p i n q with Cassava. Proceedinqs o f an
I n t e r n a t i o n a l Workshop h e l d a t Tr ivandr ium. I nd ia ,
27 Now. - 1 Dec, 1978; 103-,,12.
25. L i t s i n g e r , J.A. and Moody, K. (1975): I n t e g r a t e d pes t
management i n m u l t i p l e c ropp ing systems.
(1n) M u l t i p l e Croppinq Symposium. (Proceodincp) . American Soc ie ty o f Aqronomy Annual Meeting.
K n o x v i l l e , Tennessae, 24-29 August.
26. Loomis, B.S. and Rapoport, H. (1977): P r o d u c t i v i t y
of r o o t crops. 11n) Cock Jo Maclyntyre. R. and
Graham, M ed. Proceedings oP The Four th Symposium
o f t h e I n t e r n a t i o n a l Soc ie ty f o r T r o p i c a l Root
Crops He ld A t C IAT Cal i *Columbia .I07 August 1976,
Ottawa, ~ n t e r n a t i o n a l Development Research
Centre - IDDC 000c. 70-84.
27, McCants, C.B. and Woltz,W.G. (1967): Growth and
M i n e r a l n u t i i t i o n o f Tobacco. Adv. Aqron. 2,
21 1-265.
54
28. Mohan Kurnar, C.R. and H r i s h i , N. (1979) : In te r c ropp -
i n g systems i n Kara la State, Ind ia . (1n)
I n t e r c r o p p i n q w i t h Cassava. ( ~ r o c e o d i n q s )
I n t e r n a t i o n a l Workshop Held A t Trivandrum. I n d i a
27 Nov. - 1 Dec. 1978. 37-33.
Moreno, R,A. and Har t , R,D, (1979) : I n t e r c r o p p i n g
w i t h cassava i n C e n t r a l America. (1n) In te rc ropp-
i n q w i t h Cassava. Prooeedinqs o f An I n t e r n a t i o n a l
Workshop Held A t Trivandrum. I n d i a . 27 Nov. - 1
Dec. 1978. 17-24.
Okigbo, B.N. (1971): E f f e c t o f p l a n t i n g da te on t h e
y i e l d and genera l performanca o f t h e cassava.
(I. u t i l i s s i m a ~ o h l ) . N iqe r i an Aqr ic. 3. ~ ( 2 ) ,
115-122.
Okigbo, B.N, (1977): P r e l i m i n a r y cassava i n t e r c r o p p -
i n g t r i a l s , F23:st NAFPF N a t i o n a l Cassava Workshop
Held A t Urnudike 1977.
32. Onwuome, I .C . (1 978) : The T r o p i c a l Tuber
CropsC John Wi ley and Sons. ~ o r o n r t o a @- ,
33. Osiru, O.S.O. and W i l l ey , R,W. (1972): S tud ies on
m ix tu res o f dwarf sorqhum end beans (Phaseolus
m) b o t h p a r t i c u l a r re fe rence t o plant
popu la t ion . .I. Aoric..$ci,, Camb. - 79,(3) 531-540,
34, O r i o l i , G.A.; Mctgilner, 3.; Dar t ra , W + L ; and
Semienchuk, P.A. 1967: Accum~la~tion de materka
seca N.P.K. yea on Manihot esculenta. Bonplandia.
2, 175-182. .
35, P o r t o , M.C.M.; Pedro, A.A , , Pedro, L,P.fl, and Raymundo,
F.S. (1 979) : Cassava i n t e r c r o p p i n g i n e r a z i l . ( ~ n )
I n t e r c r o p p i n q wi th cassava . I n t e r n a t i o n a l Workshop
Held A t Trivandrum. ( ~ r o c e e d i n ~ s ) , Ind ia . 27
Nov. - 1 Oec. 1978, 25-34.
36, Rao, M.R. and S h e t t y , S.V.R. (1977): Some b i o l o g i c a l
a s p e c t s of i n t e r c r o p p i n g sys tems on c r o p weed
balance . (1n) Weed Sc ience Conference Workshop i n
I n d i a ( ~ r o c e o d i n q s ) , Andhrs Pradash A q r i c u l t u r a l
U n i v e r s i t y , Hyderabad. I n d i a , 12020th Jan.
37, Rogors, D.J. (1963): S t u d i e s of Manihot e s c u l e n t a
( ~ r a n t z ) (Cassava) and r e l a t e d s p e c i e s , - Bul l .
Torrev I&&, IP, 43-54.
38, Sinha , S.K. and Nair , T,U.R., (1971): Leaf a r e a d u r i n g
growth and y i o l d i n g c a p a c i t y o f cassava . I n d i a n 3,
Gen.And P l a n t Breedinq, 31, 16-20, - 39, Spencer , H. (1962): Rapid method of e s t i m a t i n g t h e l e a f
a r e a of c a s s a v a (f lanihot u t i l i s s i m ~ ( ~ o h l ) u s i n g
l i n e a r measurement. Trop. Agric. - 39 ( 2 ) , 147-1 52.
40, Te jwani, K.G. ; Ramakrishma, C,K,; Kurup, 0 . and Ven
Katnrarnan, K, V. ( 1 957) : Measurements o f l e a f a r e a
Tobncco, Ind ian J. Asr ic , - 2 ( 1 ) , 36-39.
41, Thung, M., and Cock, J.H. (1979): M u l t i p l e c ropp ing
c a s s a v a and f i e l d beans. S t a t u s of p r e s e n t work
at the International Centre ?or Tropical Agriculture
(CIAT) . (1n) Intercroppinq with Cassava,
International Workshop (proceedings) Held at 1 *
Trivandrum, India, 27 Nov. - 1 Dec. 1978, 7-16. - 42, Watson, D.J. (1956) : Leaf growth in relation to crop
yield. (In) The Growth of Leaves, Proceedinqs 3rd
Easter School. In Aqricultural Science, University
of Nottinqham, Ed, F.L. flilthorpe, London,
Butterworths. 178-191.
43. Watson, D. 3. (1 958) : Dependence of net assimilation on
leaf area index. Ann, Bot. 22, 37-54, - -
44, Willey, R.W. (1975): The use of shade in coffee, cocoa
and tea. &rt. Abst. 45, 791-798. - 45, Willey, R.W. (1979) : Intercropping. Its importance and
Research needs. 1. Competition and yield
advantages. Field Crop Abst. - 3 2 ( 1 ) , 1-10.
46, Willey, R e W . and Osiru, D.S.O. (1972): Studies on
Mixtures of Maize and beans (~htiseolua vulqaris)
with particular reference to plant population.
3. Aqric. Sci, Cambridge, 29, 519-529.
47, Williams, C ,No (1974) : Growth and productivity of
Tapioca (Ma - utilisima) . Development and yield o f *
tubers. Exp. Aqric, - 10(1), 9-16,
57
48. Zands t ra , H . G . (1979) : Cassava i n t e r c r o p p i n g Research:
Aqrocl i rna t ic and b i o l o g i c a l i n t e r a c t i o n s ,
( ~ n ) 1 6 t e r c r o ~ ~ i n ~ w i t h Cassava.
I n t s r n a t i o n a l Workshop ( ~ r o c e e d i n g s ) Held a t
Trivandrurn. I n d i a , 27 Nov. - 1 Dec. 1978,
Appendix I
E f f e c t o f I n te rp lan t ing and Time o f In te rp lan t ing
Cassava Through Tobacco on The Number o f Tobacco
Leaves h a r v e s t d
- - - -- - - - -
P l a n t i n date B Number o f ~ e a v e s / ~ l a n t (Weeks
Sole Tobacco 24
F-LSD N.S.
.. .. Appendix I 1
E f f e c t o f I n t e r p l a n t i n g and Time o f I n t e r p l a n t i n g
Cassava Through Tobacco on the Leaf d r y weight
( y i e l d ) o f Tobacco (g/plant).
P l a n t i n date (weeks 7 Dry weight
( g/plant
Sole Tobacco 78.4
