146 MASS. EXPERIMENT STATION BULLETIN 254 



Cucumbers — Low basic sulfate spray (0.25 per cent Cu) was equal or superior 

 to Bordeaux (0.25 per cent Cu) in controlling anthracnose and powdery mildew on 

 cucumbers as determined by yield in 1925 and by leaf counts in 1926. Both 

 fungicides appeared to be slightly injurious to the young leaves in 1926. Neither 

 spray (0.26 per cent Cu) nor dust (7.02 per cent Cu) application of high basic 

 sulfate afforded protection under the continuous heavy rains of 1927, although the 

 dust was slightly the more effective. Neither caused injury. 



Celery — Low basic sulfate spray (0.25 per cent Cu) was equal to Bordeaux 

 (0.25 per cent Cu) in controlUng early and late blights on celery as determined by 

 yield in 1925 and by leaf counts in 1926. Both spray (0.26 per cent Cu) and dust 

 (7.02 per cent Cu) applications of high basic sulfate increased the yield and grade 

 of celery in 1927, but the dust proved the more effective. Low and high basic 

 sulfate sprays (0.24 per cent Cu) were fully equal to Bordeaux (0.24 per cent Cu) 

 and superior to low and high basic sulfate dusts (6.80 per cent Cu) on celery in 

 1928 as determined by yield, although the experiment has little significance as 

 the plants did not reach marketable size due to adverse weather conditions. 



Potatoes— Low basic sulfate spray (0.26 per cent Cu) was not equal to Bordeaux 

 (0.25 per cent Cu) in controlling early and late blights on potatoes, as determined 

 by yield in 1926; nor was high basic sulfate spray (0.25 per cent Cu) in 1927. 

 Tuber rot, however, did not exceed 1 to 2 per cent in either case (Doran). Low 

 and high basic sulfate sprays (0.24 per cent Cu) were not equal to Bordeaux 

 (0.24 per cent Cu) on potatoes in 1928 as determined by yield of grade No. 1 and 

 by reduction in amount of rot. Evidently a spray of 0.24 per cent copper derived 

 from basic sulfate is not fully adequate to prevent late blight and tuber rot on 

 low lands in a wet season. This was true also of Bordeaux on the College farm in 

 the wet season of 1927, when the rot averaged from 20 to 25 per cent by count. 

 With high basic sulfate dust (7.52 per cent Cu), there was about 1 per cent by 

 weight of tuber rot in 1927. There were no checks. Low and high basic sulfate 

 dusts (6.80 per cent Cu) were not equal to a copper-lime dust (7.70 per cent Cu) 

 on potatoes in 1928, as determined by yield of grade No. 1 and by reduction in 

 amount of rot collectively. The low basic sulfate dust, however, in spite of a lower 

 copper content reduced rot rather more than the copper-lime dust. 



Fruits — Low basic sulfate sprays (0.13, 0.19 and 0.25 per cent Cu) were not 

 equal to standard lime-sulfur in controlling scab on Baldwin and Mcintosh 

 apples in 1926, and injured the foUage and russeted the fruit, especially in the 

 higher concentrations. The injury on the foUage of Monarch plums increased 

 with the concentration, but was not appreciable on the fruit. With mixed high 

 and low basic sulfate sprays (0.06 and 0.19 per cent Cu) and with Ume-sulfur, 

 there was about the same percentage of scabby fruit on Baldwin and Mcintosh 

 apples in 1927. The dilute spray with Unseed oil was no more injurious than 

 lime-sulfur and was reported a promising mixture for apples (Cutler). The con- 

 centrated spray killed the buds and injured the leaves. With mixed high and 

 low basic sulfate dusts (2.50 and 5.00 per cent Cu) on Mcintosh apples and 

 Bartlett pears in 1927, there were only a few scab spots on Mcintosh with the 

 dilute mixture. Both dusts caused a small amount of russet on Mcintosh but no 

 fohage injury. The copper content was reported about right (Drain). Low and 

 high basic sulfate sprays (0.07 per cent Cu) were not equal to Ume-sulfur in con- 

 trolUng scab on Mcintosh and Red Astrachan apples in 1928 as determined by 

 fruit counts on Mcintosh, although none of the fungicides gave adequate control, 

 probably because of too late appUcation. The basic sulfates defoliated the trees 

 seriously and russeted the fruit more than Ume-sulfur. Low and high basic 



