es RE ae RT Nee 
New York AGRICULTURAL EXPERIMENT STATION. 151 
In 1904 the Station ten-year experiment at Geneva gave the enor- 
mous gain of 233 bu. per acre due to spraying. In order to deter- 
mine whether the sprayed potatoes were better than the unsprayed 
ones for seed purposes, tubers from sprayed and unsprayed rows 
were planted in alternate rows the following season. There was a 
difference in yield of 12 bu. per acre in favor of the sprayed seed.*? 
The Station has done some work on potato scab,!? without, how- 
ever, making an important addition to the knowledge of that 
troublesome disease. Experiments made in 1887? and 1888!4 
were designed to throw light on the following points: (1) Influence 
of the soil; (2) effect of an excess of moisture in the soil; (3) 
scabby vs. smooth tubers for seed; (4) effect of stable manure; (5) 
disinfection of seed tubers; (6) effect of special fertilizers; (7) 
relation of millipedes to scab; and (8) relation between color of 
skin and susceptibility to scab. The results seem to warrant the 
conclusion that scab is more virulent in wet soils than in dry ones, 
and in manured soils more than in unmanured ones; also that milli- 
pedes are not active agents in producing scab. On other points the 
experiments were inconclusive. This was before the cause of scab 
was known. 
After the discovery of the true cause of potato scab by Dr. 
Thaxter at the Connecticut Station! in 1890 further experiments 
on the treatment of scab were undertaken in 1892.1°° Several differ- 
ent fungicides were tested in two ways: (1) By soaking the seed 
tubers in them; and (2) by spraying the seed pieces and the sur- 
rounding soil with fungicides. While there were some indications 
of benefit from both methods of treatment no conclusions could be 
drawn. 
In 1897 an experiment was made on green manuring with rye as 
a preventive of potato scab.” This has sometimes been recom- 
mended as a means of securing a smooth crop of potatoes on land 
infested with scab. The method is to sow the rye in the fall and 
plow it under the following spring shortly before planting time. In 
the Station test the use of rye in this way did not lessen the amount 
of scab in the least. 
** Unpublished. 
** Odspora scabies Thax. 
* Rpt. 6:307-315 (1887). 
* Rpt. 7:224-227 (1888). 
*° Conn. Sta. Rpt. for 1890:81-95 (1891). 
** Bul. 49:3-13 (1893); same in Rpt. 11:561-570. 
“Bul. 138:629-631 (1897); same in Rpt. 16:418-420. 
