40 BULLETIN 866, U. S. DEPARTMENT OF AGRICULTURE. 



More spray was observed on the plat treated with Bordeaux, 

 4-3-50, than on those sprayed with the Pickering sprays. It is 

 diffieiilt to explain the results obtained with the barium-water spray, 

 which, judging from the figures for rot control, produced no effect. 

 This spray gave an excellent control of fungous diseases on potatoes, 

 as compared with a Bordeaux, 5-5-50. Pickering (A) and (C) 

 sprays on plats 5 and 6, where the vines were very dense, showed 

 practically identical fungicidal power. The sprays used on plats 

 8, 9, and 10 showed good control of rot. From a comparison of results 

 with sprays used on plats 8, 9, and 10, it is impossible to determine 

 the influence of the different amounts of lime on the fungicidal prop- 

 erties of the 1 per cent copper sulphate present in the three sprays. 



Included in the 1918 tests were three commercially-sprayed plats, 

 treated with a Pickering (C) spray containing 0.6 per cent of copper 

 sulphate, a Bordeaux spray made with 0.6 per cent copper sulphate, 

 and a Bordeaux, 4-3-50, containing 1 per cent copper sulphate, such 

 as is regularly employed for spraying cranberries at Hanover Farms. 

 Two hundred gallons of each spray were made and applied with the 

 power spray apparatus to Early Blacks. Rosin-fish-oil soap was 

 used with all three sprays. The sprays were applied three times, 

 June 13, July 3, and July 24. Very little rot was seen on any of the 

 plats, and at the time of picking no differences in control of rot on 

 the three plats were evident. No check plat was employed. 



Yield. 



IN 1917. 



The calculation of the results for yield of the Centennial berries 

 (Table 12) was complicated by injury to the berries due to drawing 

 the spray apparatus over the vines four times. The high figure for 

 yield on the check plat is in part explained by the fact that none of 

 the berries on this plat were crushed by the spray cart. Unavoid- 

 able irregularities occur in the yields of all plats of cranberries 

 of any size. The yield results on Early Blacks are so close that no 

 conclusions can be drawn as to the influence of the sprays on the yields 

 of berries. 



IN 1918. 



No results which show the influence of the sprays on the yields of 

 cranberries are available. 



Adherence of Copper from Various Sprays to Leaves. 



IN 1917. 



Samples of cranberry leaves were gathered on July 10, two weeks 

 after the third spray had been applied, and on September 4, five weeks 

 after the fourth spraying, and analyzed (Table 13). 



