In 1907, Thomas Burrill wrote that regarding bitter rot, “There was nothing to do but to helplessly submit to the inevitable.” However, he continued and stated “that what formerly seemed incomprehensible is easily understandable.” Some key points he touches on regarding the management of bitter rot are weather conditions and sanitation. Obviously, there is little[Read More…]
Janna L Beckerman
Professor of Plant Pathology
Department of Botany
Area(s) of Interest: Ornamental and Fruit Diseases
Janna L Beckerman's website
Department of Botany
Area(s) of Interest: Ornamental and Fruit Diseases
Janna L Beckerman's website
It may seem like the worst is over, but apple growers should continue to be vigilant and apply fungicides even as we approach the end of the ascospore discharge period. Leaves are still highly susceptible to both primary and secondary apple scab infection until the terminal bud has set and the leaves have hardened off.[Read More…]
Diagnosing Phytophthora crown rot is difficult. First examine the crown and rule out any type of mechanical damage, including rodent damage. Early symptoms of root and crown rot include delayed bud break, small leaves (often with leaf discoloration), and twig dieback. Bark discoloration, unthrifty growth, and premature leaf drop may occur later in the season[Read More…]
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…]