THE AMERICAN POTATO JOURNAL 2I 5

din, and H o u m a , wi th respect to blossom number . W h e n these stocks were p lanted in F e b r u a r y at Baton Rouge, the resul t ing plants appar - ently developed blooms in inverse p ropor t ion to the length of t ime

the seed had been stored. T h e r e f o r e he concluded that sparse ly b looming variet ies such as T r i u m p h and W a r b a , when used fo r breed-

ing purposes , can be be t te r ut i l ized by p rov id ing a shor ter s torage

period.

LITERATURE CITED

I. Anderson, Rudolph Daniel. I936. A study of some abnormalities oc- curring in certain potato varieties in Colorado. Colorado Agr. Exp. Sta. Tech. Bul. I6.

~. Brown, B. A. I936. Continuous culture versus rotation for potatoes. Amer. Potato Jour. I3, No. II. November.

3. Bushnell, John. I936. Experiments with potatoes on muck soil. Ohio Agr. Exp. Sta. Bul. 570. June.

4. Butler, O. I936. Variations in yield of pure line Green Mountain po- tatoes grown in a controlled environment. Jour. Amer. Soc. Agron. 28: N.o. 9. September.

5. David~on, W. D. I936. Seed potatoes from bog land. Jour. Dept. of Agr. Ireland 34- No. I. 48-52.

6. Lombard, P. M. I936. Comparative influence of different tillage prac- tices on yield of the I~tahdin potato in Maine. Amer. Potato Jour. I3. No. 9.

7. Lombard, P. M. and Stuart, Vc~.m. I936. Relative vigor of apical and basal seed pieces of potato. Amer. Potato four. I3. No. 5.

8. Miller, Julian C. I936. The effect of length of dormant period upon the subsequent flowering of the potato plant. Amer. Potato Jour. 13. No. 6.

9. Miller, Lawrence P. and Denny, F. E. I936. Relation between quantity of ethylene chlorhydrin absorbed and growth response in treatments for short- ening the rest period of potato tubers. Contrib. B.oyce Thompson Inst. 8. No. 2.

Io. Miller, Julian C. and Kimbrough, W. D. I936. Irish potato investiga- tions. Louisiana Agr. Exp. Sta. Bul. 272. January.

II. Moore, I~. C. and Wheeler, E . J . I936. The Katahdin potato in Mi- :higan. Michigan Spee. Bul. 27I. June.

I2. Murphy, Paul A. I936. Some effects of drought on potato tubers. Em- pire Jour. Expmt'l Agr. (London) 4. No. ~5, r

I3. Stewart, F. C. I936. The relative vigor and productivity of potato plants from basal and apical sets cut from tubers in different stages of sprout- ing. New York (Geneva) Agr. Exp. Sta. Bul. 658.

A R M I L L A R I A D R Y R O T O F P O T A T O T U B E R S I N

B R I T I S H C O L U M B I A 1

WALTER JONES, Assistant Plant Pathologist, and H. S. MACLEOD, District Inspector, Dominion Laboratory of Plant Patholoyy,

Saanlchton, British Columbia, Canada

A dry rot of pota to tubers caused by Armillarfa mellea Vahl

ex Fr . was repor ted f rom A u s t r a l i a in I9IO by Johnson ( I ) and f rom W a s h i n g t o n Sta te in 1914 by Bailey (2 ) . I t was first observed in

1Contribution No. 473 from the Division of Botany, Experimental Farms Branch, Department of Agriculture, Ottawa, Canada.

216 THE AMERICAN POTATO JOURNAL

British Columbia in I934 in three districts where the Netted Gem, Burbank, and Green Mountain varieties were grown on land which had been recently cleared of tree growth. In general, the percentage of affected tubers is small. In 1936, however, one grower in the Fraser Valley district lost about one half ton of Green Mountain tubers from an area of approximately one and one half acres. To date the disease has been found only among the Netted Gem, Burbank, and Green Mountain varieties.

The symptoms are visible on the outer surface of the tubers as hard, brown, roughened, shrunken areas which vary in size and are somewhat corky in texture. Dark brown to black rhizomorphs are generally attached to these areas and these may also be found adher- ing to the skin at various points. The rot is usually shallow, but in several Green Mountain tubers collected, the diseased tissue extended into the medulla, (figure I ) . Tubers showing these symptoms were almost a total loss. The diseased tissue in the internal areas is light brown in color and interspersed with somewhat convoluted white mycelial plates with dark brown peripheries.

FIGURE I--ARMILLARIA DRy ROT OF GREEN MOUNTAIN POTATO TUBERS

The losses caused by this disease have been negligible in most potato growing districts, and on the whole it is not considered a serious disease. It may, however, be advisable to avoid growing potatoes on newly cleared land where the sporophores and rhizomorphs of the fungus are abundant. On land of this nature the practice of planting

THE AMERICAN POTATO JOURNAL 2I 7

potatoes as a preparatory crop for tree or bush fruit should be avoided. Potato tubers are apparently well suited for the increase of the rhizo- morphs of this parasite in the soil.

LITERATURE CITED

i. Johnson,, T. H. igIo. Notes on a fungus found destroying potatoes. Agr. Gaz. N. S..W. 21:563-566 and 699-7oi.

2. Bailey, F. D. I914. Notes on potato diseases found in the NOrthwest. Phytopath. 4: 321-323.

T H E C U L T I V A T I O N O F T H E P O T A T O IN P A M I R 1

R. L. PERLOVA

Institute of Plant Industry, Leningrad , U. S. S. R.

Pamir forms a part of the autonomous mountainous Badakhshan region of the Tadjik Republic of U. S. S. R., situated between 360 and 380 of north latitude and 73 ~ and 75 ~ of eastern longitude (Green- wich). Climatically and orographically it can be divided into Eastern and Western Pamir.

Eastern Pamir presents a multitude of wide lake basins and river valleys, situated at 4000 miles and more over sea level and sur- rounded by even slopes of high mountains often covered by eternal snows and glaciers. Its climate is severe and cold with the average annual temperature of t~ to 5 ~ C. with few frostless days during the vegetative period, of approximately two to three months. There are only 60 ram. of annual precipitations. The soil is a gray-soil, charac- terized by eternal frost at the depth of 1-2 m. but according to the data of the.two years working of the complex expedition of the Central Asi- atic State University, these soils can be very well utilized for agricultur- al purposes under the condition of using suitable agrotechnical methods. Because of the severity of the climate the native Kirghizes do not occupy themselves with agriculture, but chiefly with stock farming.

The relief of Western Pamir is considerably intersected by rapidly flowing rivers. The climate is mild and warm (average annual temp. 9-1o ~ C.). The vegetative period lasts about six months, being char- acterized by almost complete absence of frosts during the summer months. The soils are of the chestnut type. Eastern Pamir is the region of the old Iranian agriculture with primitive methods. Because of its insufficient precipitation (annual maximum of 18o mm.) it is irrigated.

1Translated into English by W. Reitz.