In spite of the early scab infection period, it is starting out as a powdery mildew year. Powdery mildew is our only "dry weather" fungal apple disease. The past 3 days and 8 of the next 10 days are predicted mildew infection days. The image above shows heavy sporulation covering an infected blossom cluster 4/2/10. The image above right shows a healthy bud on the left compared to a mildew-infected bud (right) 3/31/10. Expect secondary infection symptoms to start appearing during bloom to petal fall. Fruit infection occurs about pink stage and causes fruit russet (right).
