Eeport on the Field and Feeding Fxperiments at Wohurn. 277 
fields in the neighbourhood had also been visited by this pest. 
By August 9 the attack had extended to all the wheat plots ; 
specimens were collected and forwarded to INIiss Ormerod, the 
Society's Consulting Entomologist, for identification, and she re- 
ported on the attack as being that of the Hessian fly. Consider- 
able damage was tilso done by the corn saw-fly. Coming so near 
harvest, it would appear that the Hessian fly attack had but a 
trifling effect on tlfcj crop, which was cut on August 15, and 
stacked in the field on August 19. The straw was cut rather 
high up, and the stubble turned in at once, to prevent further 
mischief. The corn was thi'ashed October 18-21, dressed and 
weighed October 25-28. The results are given in Table I., 
page 278. 
The plots are ;^-acre ones, with the exception of the A's and 
B's, which are |- acre each. 
The season, a very dry one, was not on the whole unfavour- 
able to the wheat crop, and the results stand considerably above 
those of last year. They resemble nearly the produce of 1885, 
and are decidedly above the average of the last ten years. On 
the unmanured plots the yield was 21 "3 bushels and 24"6 bushels 
per acre against 12-2 bushels and 14-5 bushels in 1886, the 
average of the ten preceding years being 17 bushels. Mineral 
manures used alone gave even a poorer result, viz. 17'7 bushels. 
Ammonia-salts proved decidedly inferior to nitrate of soda 
this year as a top-dressing; this was probably due in great 
measure to the extreme drought. When ammonia-salts were 
used alone, the increase was only 3 bushels over the average of 
the unmanured plots, but with nitrate of soda the highest produce 
since 1881 was obtained — viz. 35 bushels. Combined with 
mineral manures, ammonia-salts (200 lbs. per acre) gave only 
3 bushels more, but nitrate of soda (275 lbs. per acre) similarly 
combined yielded 40-2 bushels, or nearly 8 bushels more than 
the average. When double the amounts of ammonia-salts and 
nitrate of soda were used, 36'5 bushels in the one case and 43"8 
bushels in the other were obtained. The omission of these 
nitrogenous manures for a single year (they having been applied 
last in the spring of 1886) reduced the produce to 2 7 "4 bushels 
and 20 '3 bushels. It would thus appear that there was more 
residue remaining from the previous application in 1886 of 
ammonia-salts than from that of nitrate of soda, the crop on the 
nitrate plot being even below the unmanured one. In the case 
of the dunged plots, the application of four tons per acre pro- 
duced some benefit, the yield being 30-2 bushels; eight tons of 
dung gave 36-9 bushels per acre. Where no dung had been 
applied since 1882, there was still an increase of three or four 
bushels above the unmanured crop. 
