Fruit IPM for August 4, 2019

Peach:

Oriental Fruit Moth: Treatments for the 3^rd generation OFM are timed for now in northern counties.

While degree model timed treatments may be done in southern counties, trap counts indicate very high populations on some farms. If trap captures exceed 6 moths per trap, then treatments are justified from now on and through the remainder of the season. Some locations already have over 40 moths per trap. Do Not let this population go, or stretch spray intervals.

Brown Rot: Most growers should be relying on a captan based program for mid-season covers, followed by better materials during the last 3 weeks pre harvest. Do not spray captan or sulfur if temperatures are above 85-90 deg F. and do not combine captan with sulfur in hot weather with poor drying conditions. See Dr. Norm Lalancette’s recent article in the Plant and Pest advisory for more information on pre harvest brown rot programs.

Apple:

Rots/Summer Diseases: Summer diseases, particularly bitter rot, are the primary diseases of concern. See last week’s newsletter for a summary of treatments, and ongoing research at Penn State in Biglerville.

Codling Moth (CM): Trap counts, particularly in northern counties have started to increase. Trap levels on some farms already exceed 5 moths per trap, and therefore merit treatment. At this time of year growers should pay more attention to trap counts than the degree day model; although general timings are presented below for this generation. Where growers have had trouble in the recent past controlling codling moth, and are not using mating disruption, then think about supplementing weekly applications of Madex along with Altacor, Voliam or Delegate applications. Make sure you are well calibrated, and that you are delivering sufficient spray volume to penetrate the tree foliage.

Grapes:

Veraison timing is important for disease control. See a recent blogpost from Dr. Nita at Virginia Tech for more information. Additional information on mid and late summer disease control from Bryan Hed at Penn State is also linked here.

Grape Root Borer (GRB): Those growers who have vineyards with GRB populations should be treating now if not already done so. Note that the trap counts below are only a guide for emergence timing and NOT an indication of widespread infestation. Prior surveys have shown that only about 30% of NJ vineyards have GRB populations that justify treatment.

Grape Trap Counts

Tree  Fruit Trap Counts – Southern Counties

Tree  Fruit Trap Counts – Northern Counties

Blueberry

Putnam Scale: We are now in full emergence of the second generation of Putnam Scale crawlers. Those growers who are treating for this insect should target a 50 gal per acre volume. Do Not make this treatment by air! This is not a flying insect, but instead a very small crawling stage that stays on the wood. Therefore the entire cane should be covered. The primary treatment window should last for about 2 weeks.

Sharpnosed Leafhopper (SNLH): Adults are being captured on yellow sticky cards, and show a marked increase from the previous week. While we cannot yet identify a flight peak yet, this does show that activity is increasing. Adult SNLH are the motile forms of the insect that spreads blueberry stunt disease, since after feeding on an infected plant, they can readily fly to an uninfected plant, start feeding and spread the disease. Nymphs do not have wings, but only have wing pads, and therefore cannot readily move from plant to plant (Figure 1).

Figure 1. Sharpnosed leafhopper adult at top and nymph at bottom, lacking fully formed wings.

Treatments should likely be targeted during mid to late August. More on this as adult activity increases.

Blueberry Traps

Atlantic County Traps

Burlington County Traps