Wet weather continues to be a problem, not just for foliar disease, but root and crown rot, as well. Phytophthora root and crown rot is observed in wet spots: low-lying areas of orchards with heavy, poorly-drained soils. These pathogens can infect all fruit producing plants. Occurrence of this disease is sporadic and tied to wet[Read More…]
Although not always possible, avoid planting in low-lying, flood prone areas. Control weeds around the trunk of apple trees, as many serve as alternate hosts for the crown rot fungus(especially nightshades). Reduce nitrogen application on young trees, and trees with excessive growth as they are more susceptible to crown rot. As there are different species[Read More…]
The recent spate of cool, wet weather has left one organism happy, Venturia inaequalis, the fungus that causes apple scab. Most of the state just underwent an extreme scab period, and unfortunately, few of us could do anything about it because of the combination of rain and wind. The revised Mill’s table (from http://www.fruit.cornell.edu/tfabp/revmills.htm )identifies[Read More…]
Upticks in powdery mildew last year, plus a mild winter (which allows the fungus to overwinter in buds) set the stage for powdery mildew (Fig.3). Early season rains kept things at bay, but the recent change to drier weather while leaves continue to grow sets the stage for this disease. Powdery mildew is active during[Read More…]
Uneven bud break is affecting some of the apple varieties at Meigs (Fig. 1). This is usually associated with apples that grow in areas with mild winters, like the one we just had. Apple trees in warmer climates often demonstrate uneven bud breaking and bloom times. With some trees exhibiting everything from silver tip to[Read More…]
Spring is in the air, and soon, ascospores, basidiospores, and conidia will be as well–Now is the time for disease management! Not sure what to spray or when to spray it? There is always the Midwest Fruit Pest Management Guide, available at: https://ag.purdue.edu/hla/Hort/Documents/ID-465.pdf For those of you who would like a different approach and layout,[Read More…]
“During the past few years considerable complaint has been made in this state of the loss of apples through rotting.” George P. Clinton, 1902. It’s been quite a season for rot. High temperatures, coupled with regular rains created a perfect storm of summer rots. If you were one of the orchards with problems, you need[Read More…]
Hopefully, everyone somehow managed to obtain effective fungicide coverage during the wet summer of 2016, and the torrential rains of the last few days. Unfortunately, many of the diseases you thought you successfully battled all summer long might still show up now at harvest, and even in a few weeks post-harvest. It is important to[Read More…]
The symptoms of flyspeck and sooty blotch have begun to make their appearance. I know this because 1). I’m starting to see spots, and 2). We have accumulated MORE THAN enough hours of post- petal fall leaf wetness needed for infection to occur. First, what is enough hours of post- petal fall leaf wetness needed[Read More…]