Frogeye leaf spot, caused by the fungal pathogen, Botryosphaeria obtusa, has been quite prevalent this year, probably due to the combination of potential (and realized) crop loss and our cool, wet spring. This is the same fungus that causes cankers on the tree, along with black rot of apple fruit (Fig. 1). Frogeye leaf spot[Read More…]
For those of you still fortunately enough to have apples, disease management continues to a greater degree than those of us without a crop. Around now (the beginning of cover sprays), the most serious apple pathogens are generally less active, terminal buds have set, leaves have hardened off (and are now less susceptible) and weather[Read More…]
The periodical cicada (Figure 1) emergence is expected to begin shortly. Female cicadas lay eggs in 200+ woody tree species (Figure 2), and they have a strong preference for grapevines, apples, cherries, peaches, & plums. Egg laying can weaken and damage branches, causing them to turn brown, die, and break off. The loss of branches[Read More…]
Snow and cold overnight lows blanketed the state on Tuesday and Wednesday nights last week (April 20-21). Many parts of the state received temperatures of 26-29 F, which caused some damage to open flowers. More northern areas of the state were not very far along in terms of crop development (early pink in apples, early[Read More…]
Freeze: There really isn’t much that can be added to the wonderful and unfortunately timely article about Frost. Critical Temperatures and Frost Protection by Rob Crassweller at https://extension.psu.edu/frost-critical-temperatures-and-frost-protection With a frost to freeze expected to cover most of the state on April 21 and 22, there will certainly be crop damage and loss (Fig. 1).[Read More…]