1922.] 



Spraying of Cornfield Weeds. 



1111 



soda had very little burning effect on the Corn Buttercup leaves 

 and in a few days was pushing on both the Buttercups and the 

 cereal crop. The stronger solution of sulphate of ammonia was 

 much more effective than the weaker spray in checking the 

 •Buttercup, and within a week its stimulating effect on the wheat 

 crop was quite obvious. The yellowish colour and stunted 

 appearance of the wheat on the plot sprayed with copper sulphate 

 solution was very pronounced as compared with the much greener 

 and taller plant on the sulphate of ammonia and nitrate of soda 

 plots. 



Experiments with Sulphate of Ammonia in Bucks. — During 

 1921, in connection with the Bucks Agricultural Instruction Sub- 

 Committee, the writer had further opportunity of testing the 

 effect of sulphate of ammonia solutions. Centres were selected 

 for this purpose in different parts of the county, each plot being 

 about 1 acre in extent. 



An ordinary " Strawson " charlock sprayer was used, and 

 conveyed from centre to centre in a Ford van. The pump, sprav 

 barrel and spray bar were fitted into a farmer's cart. 

 The spray fluid was made as follows3 : — Approximately 40 gal. of 

 water was poured into a wooden tub of about 60 gal. capacity, 

 then a 2 cwt. bag of sulphate of ammonia was shovelled in with a 

 spade, each spadeful being given a shake so as to distribute it 

 in the water. At the same time another man kept stirring the 

 solution with a stout pole. With sulphate of ammonia in good 

 condition, it was practically all dissolved by the time the bag was 

 emptied. The sulphate of ammonia appreciably increased the 

 volume of the solution, so that much less than 20 gal. of water 

 had to be added to bring the volume up to GO gal. This needs 

 to be bome in mind, as one would obtain a weaker and less 

 effective spray fluid, by adding 2 cwt. of sulphate of ammonia to 

 GO gal. of water. 



Careful notes were made of the effect of the sulphate of 

 ammonia spray on all the weeds which happened to be present 

 in the cereal crops, and a good deal of information has been 

 gathered in this way. 



It should be remembered that last year was abnormally dry. 

 very little rain falling in Bucks from the beginning of the year 

 till harvest time. Hence the weeds were tougher and more 

 difficult to kill than usual, while the stimulating effect of the 

 spray on the cereal crop was not nearly so marked as was the 

 case in 1920, largely because there was practically no reserve 

 of soil moisture to keep the cereal crop going. The usual 



