A 4-year test was carried out on the effect of sprays of captan, dodine, dichlone, and phenyl mercury acetate-captan on the performance of mature McIntosh apple trees. Increases in yield of the same trees over the average yield of the previous 5 years were 40, 31, 18 and 7 per cent, respectively, for captan, dodine, mercury-captan and dichlone. The fungicides had little effect on bloom, tree growth as measured by increase in trunk cross-section, and per cent fruit color. Mercury-captan produced larger apples indicating a thinning effect. The captan sprays produced the most attractive apples. With dichlone, fruit finish was rough. Dodine injured about 3 per cent of the apples in 2 years of the test.Dodine gave the best control of apple scab (Venturia inaequalis). Dichlone was very effective for early fruit scab but did not give good control of late or pin-point scab. Mercury gave excellent control of early scab. Captan allowed some late scab to develop.

The fruit yield of apple trees per unit area of trunk cross-section is shown to be very closely related to the author's estimate of the amount of bloom. Trees with maximum bloom score produced 46.48 kilograms of fruit per 100 square cm. of trunk cross-section, and lower percentages of bloom showed a linear relationship between the amount of bloom and yield of fruit.

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A five-year study rvas