Tree Fruit IPM Report for May 1, 2017

Fruit IPM for 5/1/17

Peach

Oriental Fruit Moth: 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): Green Peach Aphid: GPA colonies are forming now, and have been found at varying levels in southern counties. If aphids are at treatment level, you have 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). Actara will not control OFM. 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 will become more of an issue as temperatures warm and mowing and other ground cover activities become more common. 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.

Peach Scab: In addition to Rusty Spot and Bacterial Spot, peach scab requires protective applications at this time. Topsin, Topsin/Captan combinations, Gem, Inspire Super, and especially Quadris Top are the best materials for blocks that had scab last year. Both Gem and Topsin should be used at the high rate to deactivate overwintering lesions on the wood. Quadris Top contains azoxystrobin (Abound), which is phytotoxic to many apple varieties. Phytotoxic residues can remain in the tank for long periods after an application is made, even if a tank cleaner is used. Do Not use Quadris Top or Abound in the same sprayer used for apples.

Rusty Spot: An effective material should be included at petal fall, and continue through 2^nd cover on rusty spot sensitive varieties. Rally at 2.5 – 5 oz./acre is the standard and most effective product. Other effective materials include Gem, Inspire Super, and Quadris Top. Both Gem and Quadris top will control all diseases at petal fall.

Apple

Codling Moth (CM): The first codling moth flight has started. A biofix was set for CM on April 26 in southern counties. No biofix has yet been set for northern counties.

Spotted Tentiform Leafminer (STLM): Adults are flying, but are not considered a pest target at this time. This is one of the most highly parasitized insects in the orchard. We have not seen a real problem with this insect in recent years. However in recent summers we have observed an increase in trap counts and injury in a few orchards in southern counties. Monitor your orchard for damage.

European Apple Sawfly (EAS): This insect is 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. 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.

Diseases: Apple Scab, Powdery Mildew, Cedar Apple Rust, are diseases of concern at this time. The NEWA scab models are predicting about 100% ascospore maturity during this period in southern NJ and about 90% maturity in Hunterdon County. Primary apple scab spores are released during any substantial wetting and infection period. Cedar apple rust infections can occur anytime between pink and 3^rd cover.

Fire Blight: The first blossoms opened in southern counties on April 15. For shoot blight suppression start applications of low rates of apogee during bloom. In southern counties the window for the first applications of apogee has passed. From a calendar perspective, blossom sprays using Streptomycin should be applied on a 3-7 day schedule or anytime temperatures are 65° F or above and the relative humidity is 60% or above when the bloom is open. Mycoshield now has a supplemental label allowing use on apples and pears. Rotations of Streptomycin and Oxytetracyclene will help manage resistance. Some fire blight strikes have been observed on susceptible varieties in southern counties.

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