I30 



Report of the Botanist of the 



sprayed three times outyielded it by 97 bushels per acre. ('See table 

 on page 128.) The explanation of the matter is this: — On the un- 

 sprayed row there were nearl}' as many tubers as on the sprayed 

 rows, but each tuber was a little smaller. The eye notes the num- 

 ber of tubers rather than their size. The only fair way to determine 

 the increase in yield in spraying experiments is to weigh or measure 

 the tubers. 



Loss from rot. — In spite of the severe attack of late blight 

 (PhytophtJwra) on the unsprayed rows there was only a small 

 amount of rot among the tubers. There seems to have been less rot 

 than in 1902 when it was estimated to be 7.6 per ct.^ The increased 

 yield on the sprayed rows was due chiefly to the prolongation of 

 the life of the plants and to only a small extent to the prevention 

 of rot. 



At Rivcrhead. — The potatoes were dug on September 8 and sorted 

 into two grades, marketable tubers and culls, in the same manner 

 as at Geneva. 



Table V. — Yields in the Experiment at Riverhead. 



'See Bulletin 221 of this Station p. 251. 



