106 MASS. EXPERIMENT STATION BULLETIN 192. 



Copper sulfate put in the June flowage as a means of controlling diseases 

 was tried in 1917 as in previous j^ears, but without positive results. 



Tables 1 and 2 show the results of spraying with "Corona" arsenate 

 of lead. In the 1917 treatments this insecticide was used at the rate of 

 4 pounds to 50 gallons of water, with 2 pounds of Good's caustic potash 

 fish-oil soap No. 3 added. The plots were sprayed three times, — June 

 26 and 27, July 25 and 26 and July 30. " The third application followed 

 the second so closely because a severe storm washed the latter severely 

 soon after it was made. In 1918 the plots were sprayed four time 5, — 

 June 11, June 27, July 19 and 20 and August 3. In the first two appli- 

 cations 3 pounds of the arsenate to 50 gallons of water were used, and 

 the last two treatments were the same except that soap was added as in 

 1917. The 1918 plots A. L. 1 to A. L. 4, inclusive, were the same areas, 

 respectively, so numbered in 1917. In both years the checks were laid 

 out on different sides of and adjacent to the plot in each case. All the 

 plots and checks were of the Early Black variety. The berries were all 

 picked with scoops. The fruit was stored in bushel picking crates as it 

 came from the bog, and was placed in storage the day it was picked. 

 The quantity stored in 1917 varied from 1 to 6 bushels for the different 

 plots and checks, while in 1918, 8 bushels from each plot and check were 

 used. 



The crates were examined by the "seven-sample" method to determine 

 the percentages of berries showing decay. In this method seven samples 

 from each crate are examined, one being taken from the surface berries 

 of each half of the crate halfway between the middle and end; one from 

 each haK of the crate halfway between the top and bottom and halfway 

 between the center and end; one from the very center; and one from 

 the very bottom of each half of the crate halfway between the middle 

 and end. This seems a most satisfactory way to sample in inspecting 

 the crated fruit. 



Both years all the plots but A. L. 2 yielded fruit of much better quality 

 than that from the check areas, the improvement being most marked 

 in 1918, when more treatments were applied. These tests and those of 

 1916 ^ show that arsenate of lead has a distinct fungicidal value as a 

 treatment for the Early Black variety. What fungi are affected by it, 

 however, has not been determined. 



1 Bui. No. 180, Mass. Agr. Expt. Sta., 1917, pp. 189-192. 



