156 MASS. EXPERIMENT STATION BULLETIN 206. 



Table 6. — Statio}i Bog Early Black Spraying Plots {Fungovf r)-'fieases) 

 treated with Calcium Arsenate, 1920. 



Plots and Checks. 



Area 

 (Square 

 Rods). 



Yield 



per Square 



Rod 



(Bushels). 



Storage Period. 



Percentage 

 of Berries 

 showing 

 Decay at 

 End of 

 Storage. 



A. Lime 1, 

 Check, 



A. Lime 2, 

 Check, 



1.63 

 1.94 



1.39 

 1.58 



Sept. 27 to Dec. 6 

 Sept. 27 to Dec. 7 



Sept. 27 to Dec. 4 

 Sept. 27 to Dec. 1 



20 85 

 28.06 



10 63 

 16.52 



With all the spraying plot.s having more than one check, the checks 

 bordered different sides of the plot. The berries were all scoop-picked 

 and stored in bushel crates as they came from the bog. At the end of the 

 storage the fruit was examined by the "seven-sample'' method^ by the 

 screeners emploj^ed at the station, under the writer's supervision, the in- 

 spector's cup of the New England Cranberry Sales Company being used 

 for sampling. The Sales Company's hand grader was used to facilitate 

 the work. 



In both 1919 and 1920 the^ vines sprayed repeatedly with lead arsenate 

 for three or more years had such a growth of runners that they were hard 

 to scoop. As the surrounding bog showed no such development, this was 

 clearly a reaction to the insecticide. The sprayed vines seemed to show 

 a slight reduction in number of uprights. On the whole, the effect of the 

 spraying on the vines was distinctly undesirable. 



In 1920 Dr. Shear and his assistants made cultures of the fungi in 

 twenty rotten berries taken at random at the end of the storage period 

 from among the fruit of each of three of the lead arsenate plots and the 

 fruit of the checks on each of these plots. Table 7 shows what fungi were 

 found. Apparenth' the spraying had reduced both Phomopsis and Fnsi- 

 coccum pvtrefade7is greatlj', and had affected Glomerella, Sporonema and 

 Dematium little, if any. These conclusions are supported by the fact 

 that mostly negative results have been obtained in spraying Howes vines 

 with lead arsenate, for studies in previous seasons * showed that on the 

 station bog Glomerella was relatively a much more important disease of 

 the Howes variety than of the Early Black. 



' In tliis 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 half 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. 



2 Mass. Agr. Expt. Sta., Bui. No. 198, 1620, pp. 88-92. 



