July 15, AppleTalk Call Summary

AppleTalk Conference Call Summary
Tuesday, July 15th, 2014, 8:00 – 9:00 a.m.
Presenter: John Aue, Threshold IPM.
Moderator: Peter Werts, IPM Institute of North America; questions or comments, pwerts@ipminstitute.org

July 15th Call download: Click Here

Agri-tourism liability training minute 0:20
Brown County UW-Extension is hosting a meeting Monday, July 21, 7:00-9:00pm, on the new Agri-tourism limited liability law. If your orchard has a u-pick operation or offers recreational activities, this new state law may apply. More information can be found below.

Precision Ag apps 3:15
Growers looking to track field details, scouting reports or weather data can utilize a new app offered by The Climate Corporation. The software is offered for smartphones in a basic and pro format and can be found at https://www.climate.com/.

Marssonina leaf blotch 8:30
Marssonina leaf blotch is a foliar disease with a similar life-cycle to apple scab; overwinters as a fungal spore in leaf litter on the orchard floor. Contrary to apple scab, it is a warm weather disease with infection periods occurring in mid to late summer. This disease is of greater concern in years with hot and humid weather. A definitive sign is early leaf drop occurring in August and early September. Some cultivars are more susceptible than others. Note: varieties such as Golden Delicious are prone to early leaf drop without the presence of this pathogen. Photos and additional information can be found on the June 17 AppleTalk.

Fruit rots 14:00
Signs of black, white, and bitter rot are beginning to develop. Possible lesions are showing as smooth, brown or dark circles that are one to three millimeters in diameter. They differ from scab lesions in appearance and texture; scab lesions are rough, grey circles. If symptoms are discovered, it is important to deduce that injury is not a result of physiology or mechanical damage, as some cultivars have fruit with large lenticels. To diagnose, place damaged fruit in sealed container and store at room temperature for ten to fourteen days. Symptoms should develop rapidly into a larger, more visible lesion.

New miticide options and resistance management in apples 24:10
Growers applying miticides are provided a new mode of action with Nealta (cyflumetofen). Cyflumetofen is effective on all stages of mites and provides growers an alternative when combating or preventing resistance. In a similar class to Envidor (spirodiclofen), Nexter (pyridaben) and Portal (fenpyroximate) Cyflumetofen can function in a rescue situation. Note: to prevent resistance it is important to rotate between two or more classes of miticides.

While conducting mite sampling or inspecting leafs with bronzing, look for dead mites among adults, nymphs, and eggs. Many orchards have healthy populations of predator species which can provide bio control. If damage is showing and mite populations are near or above threshold, predation may not provide suppression; chemical control may be the only option.

Insecticides for second generation codling moth and secondary pests 36:10
When selecting insecticides for second generation codling moth (CM) control, it is important to consider a material’s activity on secondary pests. Materials such as Altacor (chlorantraniliprole) or Delegate (spinetoram) will also control internal lepidoptera, leafrollers and leafminers. They do not control Japanese beetle, stinkbugs and tarnished plant bugs. These products are registered for apple maggot (AM) suppression and can provide adequate control if trap counts are below or near threshold, example below.

Trap ID 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
AM 1 1 0 1 0 1 0 1 0 0 2 0 1 0 1 1 0 1 1 0

If higher amounts of AM are captured, options are limited to more broad-spectrum materials; classes and associated risks follow. Pyrethroids, i.e., Asana (esfenvalerate), are toxic to beneficial insects and can cause outbreak of secondary pests. Carbamates, i.e., Sevin (carbaryl), have a two to three day activity period and are toxic to beneficials. Organophosphates, i.e., Imidan (phosmet), can be used at a lower rates than what is recommended for codling moth and can be applied on an alternate-row-middle (ARM) basis. An alternative material which is less toxic to beneficals is Avaunt (indoxacarb). It is important to note that in orchards with high AM populations ARM applications are not recommended.

Stink bug or tarnished plant bug damage is beginning to appear, scout the inside of the canopy for pencil-eraser sized bruising on fruit and egg masses on foliage. Materials are limited for these pests. Avaunt and neonicotinoids, i.e., Assail (acetamiprid), Calypso (thiacloprid) and Admire Pro (imidacloprid), will offer control with low CM resistance issues. Stink bugs and apple maggot are traditionally not an orchard wide pest. If treating for CM it is acceptable to spot spray for these pests. Materials for woolly apple aphid, i.e., Alias (imidacloprid) and admire (imidacloprid) or the newly registered Closer (sulfoxaflor), are not a concern for CM resistance. Note on resistance management: a CM material applied during first generation can be reapplied for secondary pests during second generation if another insecticide is the primary control for CM.

Additional articles and resources
• Agri-tourism limited liability law educational meeting July 21
•The Climate Corporation