148 REPORT OF THE BOTANIST OF THB 
age of the field was such that it ought to have been in its prime, 
but previous attacks of the rust had injured it so severely that 
the yield was only about one-half the average yield per acre 
throughout the Long Island asparagus section for the season, as 
the records of the Canning Company show that the average yield 
per acre for 1900 was about 800 bunches. In reality the yield 
of this field was only about one-third what a good field should 
yield. As an outcome, with all the precautions taken to eliminate 
uncertain factors, the results obtained as a whole were not as 
marked as were those in 1899. Some idea of the growth of 
asparagus on this field can be obtained from Plates XIV and XV 
taken the middle of September, 1900. 
By giving the results as percentages the above conditions are 
somewhat eliminated and the yields expressed in this manner 
probably show accurately what. can be done by spraying under 
the most unfavorable conditions. These conditions were: First, 
a field with a low yielding capacity; and second, a field having 
alternate unsprayed rows as a constant source of infection to the 
sprayed rows. In addition it should be observed that the even 
or unsprayed rows showed a slight advantage over the sprayed 
rows in yield previous to spraying. See Table III. 
With all these disadvantages to contend with, the increased 
yield from spraying shows in percentages a gain in yield of 47.8 
per ct., and in value 44.5 per ct. This amount can surely be taken 
as representing what is to be gained from spraying alone without 
the aid of any other measures or methods. 
It can be shown that the average yield in bunches from the 
Long Island fields the past year was between 750 and 800 bunches 
per acre. The records of the Canning Company also show that 
previous to the attacks of the rust the same fields yielded be- 
tween 1,500 and 2,500 bunches per acre. It must not be assumed 
that from the fact that spraying gave an increased yield of 45 
per ct. over unsprayed rows that the average yield of 800 bunches 
can be increased that amount. This percentage simply means 
that the yearly decrease in yield from the attacks of the rust ean 
be reduced 45 per ct. Yet a study of Table III would indicate 
