Fruit IPM for 5-10-2016

Peach

Oriental Fruit Moth: Oriental fruit moth is the primary key insect in peaches that is the ‘worm in the fruit’. It has 4 generations in NJ. During the first 2 flights, eggs are laid primarily on leaf petioles and growing shoots. Larvae hatch and mine down the new growth. As the larvae feed on developing shoots, flagging is seen when the growing terminal dies and falls over. Some eggs from the second generation and much of the 3rd and 4th generation are laid on the fruit surface. When the larva hatch, they bore into the fruit, causing infested fruit. First generation timings are updated below:

Plum Curculio (PC): PC adults usually begin egg laying once the fruit is out of the shuck. Preferred materials that offer PC control now are Avaunt, and Imidan. If using high rates of a neonicotinoid (i.e. Actara, Belay, Assail), be aware that there is a synergistic effect when used in tank mixes with DMI materials (i.e. Rally) with regard to bee toxicity. Neonicotinoids should not be used if there are any flowering weeds in your orchard. Those flowering weeds will attract bees, which will be killed by the insecticide. The use of most of these products when bees are present is off label and therefore not legal. If pyrethroids are being used, then high rates are advisable, since low rates often do not control PC, especially in hot weather. Where PC is a problem, growers should rotate away from pyrethroid insecticides if possible. Actara and Belay will also control PC (and GPA), but not OFM.

Green Peach Aphids (GPA): GPA colonies are forming now, and have been found in southern counties. If you have controlled OFM, and aphids are at treatment level, and your ground cover is clean of blooming weeds, a good choice that will cover catfacing insects, aphids, and plum curculio is Thiamethoxam (Actara and in VoliamFlexi). Examine trees for the presence of colonies by standing back and looking at the entire tree. Clusters of curled leaves will define a single colony. Count the number of colonies on ten trees and use a treatment threshold of 2 colonies/tree at petal fall to shuck split for peach, and 1 colony/tree for nectarine. If treating aphids alone then Movento @ 6 oz/A is a good non-neonicotinoid choice. Movento must be combined with a spreader/penetrant spray adjuvant. Used later during late May to early June this will also control scale. Lannate can also be used, but is not quite as effective.

Tarnished Plant Bugs and Other Catfacing Insects: This is the other key insect complex at this time of year. Tarnished plant bugs (TPB) will become more of an issue as temperatures warm and mowing and other ground cover activities become more common. The worst TPB problems we have seen have been when there are many dandelions in the aisle ground cover. As the aisles are mowed, the bugs move into the fruit and feed within the trees. General spray timing at this time of year should still be targeted for Oriental Fruit Moth and/or Plum Curculio (PC). Most materials, except the diamides (Altacor, Belt, Tourismo) used for these pests will have some efficacy for plant bugs.

Bacterial Spot: Copper formulations should be used starting now to suppress bacterial spot. Generally we recommend starting at 0.5 ozs metallic copper and gradually lowering the rate as the season progresses. The rate applied will depend on the formulation. Dr. Lalancette published a chart listing common copper formulations and rates for peach and nectarine applications. Avoid combining copper with captan especially if it has been overcast for several days. Also avoid acidic spray solutions when applying copper.

Apple

Codling Moth (CM): The first codling moth flight has started. The first adults were caught on April 22 in southern counties, and April 26 in Hunterdon County. Due to the cooler weather, codling moth and other Lep. activity took a ‘breather’ last week. That only means that the treatment timings have been delayed:

European Apple Sawfly (EAS): This insect is active and will be active through bloom and into petal fall and first cover. Adult females lay eggs just under the skin of freshly set fruit, and the young larvae mine just under the skin. If let go, the larvae will cause extensive fruit damage. Where this insect is active, it is a primary target at petal fall. In orchards of mixed variety plantings, the petal fall spray for the entire planting is prolonged. This enables EAS to start damaging the first varieties where petals fell earlier before a petal fall spray could be applied to the entire block. Petal fall treatments should not be delayed, especially in northern counties.

Diseases: Apple Scab, Powdery Mildew, Cedar Apple Rust, are diseases of concern at this time. The NEWA model predicts significant infection periods on 5/10-11 and 5/13 in Elk Twp, Gloucester County. Essentially, 99% of overwintering ascospores are mature and have been released as of the last infection period. However, secondary (conidial) infections are possible during any predicted infection period. Since the latest infections will not be visible until at least May 24, growers should maintain fungicide coverage. In the Pittstown area, Hunterdon Co., scab infections are also predicted for 5/10-11 and again on 5/13. Spore maturation is close to that in southern counties and the recommendations remain the same. Cedar apple rust infections can occur anytime between pink and 3rd cover.

Fire Blight: The NEWA/Cougerblight model predicts low infection periods for the Pittstown, Hunterdon Co. area up through May 11, and cautionary conditions through 5/15. These are weather dependent predictions; so if temperatures warm and more rain is predicted, then severity can also increase. There is still bloom remaining on some varieties in northern areas, so we are not out of the woods for fire blight conditions. Mycoshield now has a supplemental label allowing use on apples and pears. Rotations of Streptomycin and Oxytetracyclene will help manage resistance.

Scouting Calendar Tree Fruit Southern Counties

The following table is intended as an aid for orchard scouting. It should not be used to time pesticide applications. Median dates for pest events and crop phenology are displayed. These dates are compiled from observations made since 1995 in Gloucester County. Events in northern New Jersey should occur 7-10 days later.

Tree Fruit Trap Counts – Southern Counties

Tree Fruit Trap Counts – Northern Counties