At midseason, scout fruit (20-30 apples or pear) in the interior canopy of sample trees. Signs of this disease are more obvious on light colored fruit, like Golden Delicious, Pristine, or Yellow Transparent. The disease is worse in poorly pruned trees in the wetter, foggy, slow-drying areas of the orchard. This year, in some parts[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
Warm, wet, summer weather, coupled with any lapses in orchard sanitation, can result in summer disease outbreaks. At Meigs, we are seeing the foliar stage of Botryosphaeria, aka frog eye leaf spot (Fig. 1). On the plus side, we won’t be surprised when we see black rot on the apples at harvest (Fig. 2). Fortunately,[Read More…]
We are already receiving reports of brown rot, caused by several different types of the fungus Monilinia., Many of these are causing shoot blight, but we are receiving samples of brown rot on cherry fruit. Brown rot is a common and destructive disease of stone fruit, a closely related group of trees that include peach,[Read More…]
Fire blight seems to have established itself in many orchards throughout the state, meaning it can still be a huge threat in the event of trauma, like hail, due to secondary spread. Secondary spread develops when stormy weather, especially hailstorms, occurs after the primary (blossom) infections. The amount of fire blight that develops after severe[Read More…]
Although the season for primary scab infection is winding down, this cool, wet weather is making for an excellent infection period for juniper rusts (Gymnosporangium spp). John Obermeyer and I created this time-lapse video to help explain the complicated lifecycle of this fascinating pathogen: http://tinyurl.com/j3s3t92 The juniper rusts standout due to the conspicuous nature of[Read More…]
Fire blight, caused by the bacterium Erwinia amylovora, is a devastating disease of apples and pears. Epidemics of the disease develop quickly, particularly in a climate of warm, wet weather, with hail events—like last night’s 0.75” to 1.5” hail! The type of management program developed by each orchard will vary considerably based upon a variety[Read More…]
Weather for 2016 continues to be unpredictable. And although bad weather can damage crops, it does little to stop the pathogens that plague pome fruit. The past few weeks of cool weather has slowed things down, but not scab—at least, not completely. All plants, insects, and pathogens develop in response to temperature–The warmer the weather,[Read More…]
Ascospore release is timed to optimize infection, which happens around tight cluster through petal fall. This is when all the fun really begins: Ascospores are at their peak and ejecting, and apple tissue is expanding, providing a larger, susceptible canopy that spores can hit. That excellent timing is the poetry of evolution in motion. Other[Read More…]
A black swan refers to an event that defies expectation and that would be extremely difficult to predict. This spring is one of those. And although it seems unlikely that we will emerge from our last frost-free date (May 15 here in Tippecanoe County) unscathed, it could happen and then you could end up with[Read More…]