Fruit Crops Edition

Seasonal updates on diseases, insects, weeds impacting tree fruit and small fruit (blueberry, cranberry, and wine grape). Fruit Pest Alerts are also available via this category feed.
 
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Fruit IPM for August 12, 2020

Peach:

Stink Bugs Apples and Peaches: BMSB populations are generally low and little changed since last week. However, hatching egg masses are present statewide. Therefore populations can increase in the near future. As the peach season comes to a close, BMSB has the potential to be more of a problem in apples. [Read more…]

USDA Announces More Specialty Crops, Nursery Crops, Cut Flowers Eligible for CFAP Payments

The U.S. Department of Agriculture (USDA) announced today that additional specialty crops, including nursery crops and cut flowers, are covered by the Coronavirus Food Assistance Program (CFAP) and that the deadline to apply for the program is extended to September 11th. [Read more…]

The Show Must Go On(line) – 2020 Ag Progress Days Virtual Experience

Continuing a 50-year tradition, Penn State’s Ag Progress Days, brought to you by their College of Agricultural Sciences, is a one-stop shop this week, August 9-12, 2020, for the latest research, management practices, and regulations in agriculture.

This year, Penn State Extension educators and faculty have come together to provide a FREE virtual learning program filled with the latest in Ag research and best practices. This event is being offered at no charge to participants, but registration is required to receive the link to access a webinar. Even if you missed a day or a session, all registrants will receive access to the webinar recordings.

Online registrants can choose from more than 46 live webinars and get questions answered by the experts. Just check out the the live webinar schedule and register online. [Read more…]

Farmland Assessment for Woodland Owners Webinar

On Thursday, August 20th at 7pm, a free webinar entitled “Farmland Assessment on Woodlands: Multiple Benefit Activities” will be presented as part of the “Backyard Forestry in 90 Minutes” online program. The presenter, Andrew Kimm, is the President of New Jersey Forestry Association (NJFA). This session discusses the implementation of Farmland Assessment on woodlands and the many benefits derived from the active devotion practiced on those lands. [Read more…]

Fruit IPM for 8/4/2020

Grapes:

Spotted Wing Drosophila (SWD): The spotted wing drosophila is an invasive fruit fly which can infest sound ripe thin-skinned fruit. The SWD female has a saw-like ovipositor which she uses to literally saw through healthy skin and deposit her eggs, which develop into small maggots. At this time of year each generation takes slightly over 1 week to complete. Each female can lay about 300 eggs over her lifetime, and given the time of year it is, we will probably see 3-5 more generations by the time grapes are harvested. Over the past several years we have monitored SWD in vineyards during August through September. A well-known link exists between high populations of native fruit flies and the prevalence of late season sour rot in grapes. What we don’t know is how the prevalence of SWD might be able to aggravate or help increase the late season populations of native fruit flies, or if the total fruit fly complex (native and invasives) is higher because of the presence of SWD. [Read more…]

The 2020 Hurricane Season: A Phytophthora Epidemic on Tree Fruit?

You’ve probably heard it by now. The National Oceanic and Atmospheric Administration (NOAA) predicts an above-normal Atlantic hurricane season for 2020. NOAA predicts “a 60% chance of an above-normal season, a 30% chance of a near-normal season and only a 10% chance of a below-normal season.” This translates to 6-10 hurricanes (>= 74 mph winds), including 3-6 major hurricanes with winds of 111 mph or greater.

What does this forecast have to do with tree fruit production? These high winds may cause tree fruit roots to crack and split.  Wounds created by this activity allows for entrance of the Phytophthora root rot pathogen. Flooding also facilitates movement of pathogen spores through the soil. Once infected, cankers and root rot develop during subsequent months, leading to tree death this fall or next spring and summer.

Although Isaias is only a tropical storm, winds may get high enough to cause some damage to anchoring roots.  Nevertheless, we still have four more months of the Atlantic hurricane season remaining, which runs from June 1 through November 30. Given the potential for loss and the above normal risk for hurricane development, it is probably prudent to review some basic information on disease development and control.

Peach and apple trees at 3 to 5 years of age are most susceptible to wind injury and subsequent infection by Phytophthora species. If trees are leaning to one side, or there is open space around the collar, this is a good indication of “tree whipping” and therefore root injury. Younger trees tend to be more flexible and therefore less likely to be damaged, especially when the soil is softened by excessive rainfall. Older trees with large, well-developed root systems are more likely to fend off the wind; limb breakage and fruit loss may be a bigger concern on these trees. Of course, wind speed plays an important role in the severity of damage across all age groups.

If injury is thought to have occurred, fungicide application should be considered immediately after the storm subsides to limit Phytophthora root and crown rot development. Ridomil Gold, applied to the soil, is the recommended fungicide. Foliar applications of a phosphorous acid material, such as Aliette, Agri-Fos, Phostrol, etc… are alternative controls.  If damage is severe across all age groups, one approach would be to apply Ridomil to 3-5 year old trees and a phosphorous material to young and old trees.

If time and weather permits, application of root or foliar fungicide prior to the hurricane may help “immunize” the trees before infection can occur. Both types of fungicides are highly systemic. However, one needs to allow time for the Ridomil to move through the soil and be absorbed by the roots. Excessive storm flooding could wash away the fungicide before it has a chance for root absorption.  Of course, once these materials are applied, the hurricane will most likely change course! Hence, the disadvantage of applying before the storm.

For details on application and rates of Ridomil Gold and Aliette, see the NJ Tree Fruit Production Guide (2016 issue) and product labels.