New YorkK AGRICULTURAL EXPERIMENT STATION. 17 
ness experiments, including 152.75 acres, the average gain due to 
spraying was 30.8 bu. per acre; the average total cost of spraying 
$5.90 per acre; and the average net profit $17.07 per acre. Twenty- 
four volunteer experimenters reported gains averaging 30.5 bu. per 
nere: 
Thus far the results are highly favorable to the practice of spray- 
ing. In the ten-year experiments at Geneva the average gain for 
six years from spraying every two weeks has been 121.7 bu. per 
acre, and from spraying three times during the season 93.5 bu. At 
Riverhead the corresponding gains have been smaller — 60.5 bu. 
and 32.5 bu. respectively. 
In 62 business experiments made in five years the average gain 
due to spraying has been 49 bu. per acre and the average net profit 
from spraying $19.86 per acre. In 177 volunteer experiments re- 
ported in four years the average gain from spraying was 50.3 bu. 
per acre. 
Alfalfa troubles—— The increasing interest in alfalfa culture in 
New York seemed to warrant an investigation of the various 
troubles to which the crop is subject; and this investigation fur- 
nished material for Bulletin No. 305. Special attention has been 
- given to dodder, fungus diseases and the impurities and adulteration 
of seed. The chief difficulty with alfalfa in New York is to get the 
crop established. Several factors may be concerned in this: Poor 
seed, sour soil, wet soil, sowing with a nurse crop, lack of nodule 
bacteria, lack of humus, weeds, leaf spot disease, close cutting and 
winter injury. Dodder is often a serious pest. It is perennial, not 
annual as generally believed. Trouble with it is avoided by sow- 
ing only dodder-free alfalfa seed. The Station will analyze seed 
samples free of charge. Dodder seeds may be removed from al- 
falfa seed by sifting if the proper kind of sieve is used. The most 
practicable method of eradication is that of burning over the dodder- 
infested spots. The only important fungus disease is leaf spot. 
This causes an enormous loss in the aggregate, but seldom ruins the 
crop completely. The remedy for leaf spot consists in mowing 
whenever the plants turn yellow and become so badly diseased that 
their growth is severely checked. The investigation disclosed the 
existence of several new alfalfa diseases the most important being 
one called “ yellow top,” the cause of which was not definitely de- 
termined. There are no yery important insect enemies of alfalfa 
in New York, 
