University of Vermont

by Terence Bradshaw

As the calendar flips to August, it’s time to wrap up field activities in preparation for harvest in Vermont orchards.

Foliar nutrient analysis – It is the time in the growing season to collect leaf samples for analysis. Samples are usually collected between July 15 – Aug. 15. The UVM Agriculture and Environmental Testing Lab can provide analysis, but at this time their output does not generate fertility recommendations. The following are potential options of labs for analysis. It is recommended that you contact the lab for instructions and costs before samples are sent. Plus, it is important to confirm that they will send recommendations along with the analysis.

(1) University of Maine Analytical Lab: http://anlab.umesci.maine.edu/
(2) University of Massachusetts Soil and Tissue Testing Lab: http://www.umass.edu/plsoils/soiltest/
(3) Cornell Nutrient Analysis Lab: http://cnal.cals.cornell.edu/

Wrapping up spraying – Primary insects of concern are apple maggot and codling moth. Both should be managed in high-pressure orchards. AM can often be managed with a single insecticide application based on monitoring with red sticky traps. The threshold is one fly per unbaited trap, or five flies per trap if apple volatile baits are used. Codling moth are entering their second flight in many orchards, so management is advised if this pest is a problem for you. Insecticide options are listed in the 2014 New England Tree Fruit Management Guide. Dr. Arthur Agnello discusses these summer insect pests in more detail in the July 7, 2014 issue of Scaffolds .

Summer diseases – It is important to maintain fungicide coverage to protect against sooty blotch, fly speck, and summer fruit rots. Materials should be applied after every 200 accumulated hours of leaf wetness or 2 inches of rainfall, whichever occurs first. Except on later-harvested cultivars, a fungicide application made by mid-month should provide good control through harvest. For retail orchards, fungicide sprays are likely wrapped up by now.

Remember to watch pre-harvest intervals on all products at this time of year.

by Terence Bradshaw

We’re in a bit of a quiet window for pest management in Vermont orchards. Apple scab primary ascospore release is done, and if you have no scab in the orchard, you’re done for the year managing that disease. For anyone with a scab issue, maintaining fungicide coverage every 10-14 days or after 2″ of rain will be important until terminal bud set when leaves and fruit become less susceptible to secondary infections. I’ve seen little fire blight, despite the infection periods predicted in the pest models. I’ve said this before- cut out any fire blight strikes as soon as you see them, and feel free to contact me to evaluate any questionable strikes. I have seen several instances of Nectria twig blight this season that look much like fire blight, but are caused by a relatively weak fungal pathogen. Nectria often infects winter-damaged wood, which I am seeing a lot of this year. The most notable characteristic that identifies Nectria compared to fire blight is that Nectria-infected shoots will have a very distinct delineation between dead (brown) and live (green) tissue at the base of the dead shoot. Fire blight shoot blight will typically show a gradation between dead and living tissue as well as water soaked cambial tissue in the area of visible infection. The only management technique for Nectria is to prune it out, and maintain the orchard with good pruning and nutrition to ensure good cold hardiness. Summer diseases such as sooty blotch/flyspeck and fruit rots are the main concern now. Dr. Dave Rosenberger’s comments from June 23, 1014 issue of Scaffolds provide good insight into managing these diseases. Take home message (read the article for specifics): Captan alone or with another material will likely be in your spray program every 2-3 weeks for the next month or two, especially if this wet weather continues.

Apple maggot traps should be hung any time now to monitor for this pest. I observed my first trapped apple maggot fly at the Hort Farm yesterday in an especially problematic block, so they will be flying in commercial orchards any day now. Other insect pests of concern potentially include obliquebanded leafroller and codling moth. skingsle ASAP.

-Terry

by Terence Bradshaw

Please see the attached itinerary for the June 30 Champlain Valley Orchard Tour. Cornell Entomologist Peter Jentsch will be with us on the tour to discuss summer insect pest management.

We will begin at 9:30 AM at Hick’s Orchard in Granville, NY, then travel north to Champlain and Sentinel Pine Orchards in Shoreham, VT. This will be a self-driven, caravan-style tour. We will provide drinks and light refreshments, but please plan on packing a lunch for the day.

RSVPs are requested, please email Sarah Kingsley-Richards with your name and the number of persons who will attend at: skingsle

150630_SummerOrchardTour.pdf