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…]
Pome Fruits
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…]
After what can only be described as a very early spring, we are entering the unusual situation of worrying about fire blight in April. Summer-like weather, rainfall, thunderstorms and hail mean that growers should be very concerned about fire blight. It is important to note that the fire blight pathogen, Erwinia amylovora, is always present[Read More…]
Spring temperatures and the season so far It seems like it’s been warm and that we’re way ahead of normal. But the data paint a slightly different picture. First, let’s not talk too much about “normal”. In the last 10 years or so that I’ve been plotting these data, EVERY year has been warmer than[Read More…]