Tree Fruit Edition

Seasonal updates on insects, diseases, weeds, maturity dates and cultural practices impacting only tree fruit.
 
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Fruit IPM Report 5-13-2015

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Peach

Oriental Fruit Moth (OFM): The flight captures really jumped this past week, especially in northern counties where some farms are seeing over 100 moths per trap. This is a reference point for 2 factors: First, OFM treatments should be ongoing during this time – see table below; and the first generation flight is usually the highest, and the most important to control. For those growers using the diamide insecticides (Altacor, Belt, Voliam mixes, and Tourismo), the timing for the second application in southern counties is now. Insecticides are required according to the degree day timings in the table below. These timings should be used for most farms. If you have high insect pressure, then additional sprays may be needed. If your trap counts exceed 6-8 males per trap 7 to 10 days after the second spray, then additional controls may be required.
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Fruit IPM Report 5-7-2015

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Peach

Thrips including western flower thrips: Thrips are being found in southern peach and nectarine blocks. This is common in years when we have warm dry weather during and shortly after bloom. Delegate is the best material to use, followed by Lannate. Entrust can also be used but will be more expensive. Both Delegate and Lannate will control OFM, but neither does a good job on PC. Closer is labeled for thrips suppression, but it’s use is discouraged if high thrips populations are present.

Oriental Fruit Moth (OFM): As of 5/7 we have accumulated 229 DD in southern counties. In northern counties the biofix was set for 4/28. We have had 140 DD accumulate since then.  The first of two applications for OFM should be going on now in southern counties, and about 5/10-12 in northern counties (using Snyder Farm as our degree day point).
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Of Thrips and Aphids

Ocassionally, flower thrips can be an early season pest of peach and nectarine, especially when conditions during bloom are hot and dry. That seems to be the case this season as 6 out of 7 nectarine blocks scouted in Gloucester County had low populations of thrips present. At least one block had low levels of injury present. Mostly adults were found but examinations of fruitlets found some nymphs present in the shucks. If left untreated, damage can occur unless conditions turn cool and wet. Growers can scout for thrips using beating trays to look for adults, or by collecting blossoms to look for nymphs feeding inside the shucks. Peach may be less susceptible to damage than nectarine because the fuzz acts as a deterrent. Growers should also look for aphid populations while scouting for thrips as aphids are just starting to appear in southern county orchards. Use a treatment threshold of 1 aphid colony per tree in nectarines and 2-4 colonies per tree in peach.

There aren’t many choices for thrips control in Nectarines.  Delegate and Entrust at the high rates are very effective.  Where aphids are also present, the neonicitinoids Actara and Closer will control aphids but may only suppress thrips. Lannate SP has a good rating for thrips and aphids in our production guide but field experience is variable. Carzol is no longer labeled for Peach and Nectarine.

Remember also that Oriental Fruit Moth, Plum Curculio, and native plant bugs are key pests at this timing so any insecticides applied for thrips and/or aphids will be in addition to applications of effective materials for these important pests.

Fire Blight Alert

The Cougar Blight model over at NEWA is predicting a high risk of fire blight for this coming week, due to the coming hot weather and high humidity along with a chance of showers.

Currently May 5-9 looks like a high risk period for infection. Growers should apply antibiotic to any apple or pear blocks with open blossoms prior to any risk of infection. Streptomycin and oxytetracycline formulations are generally thought to provide 1-2 days protection and possible 24 hours back action. A predication of high risk over a 4 day period may require 2 applications 2 days apart, especially if there is rainfall, and/or the orchard is not yet at full bloom. Follow the label rates. 24 ozs. of strep/acre should suffice. Check your local conditions using NEWA and check back daily as the prediction may change.

Fruit IPM Report 4-28-2015

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Peach

Petal Fall Insect Complex: An OFM biofix was set for April 20 in southern counties. Treatments for the first flight will be due at 170-200 degree days after the first trap captures or “biofix.” According to the NEWA weather station in Upper Deerfield, we have had 49 degree days accumulate since 4/20. This timing usually coincides with late petal fall to shuck split, however we are a little late this year, since we have about 120 degree days to go until the first OFM treatment.

Since we are still waiting for the OFM timing, the initial petal fall spray will primarily target plum curculio, tarnished plant bug and other catfacing insects. Plum curculio is active, and will feed on blossoms and freshly set fruit. See last week’s newsletter and the Tree Fruit Production Guide for insecticide options. Given the current insect targets, Avaunt is one of the better materials for plum curculio (PC) at this time, and also covers Oriental fruit moth and tarnished plant bug. We are not concerned with BMSB at this time, so many of the other materials which are effective for BMSB can be saved for later in the season.
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Fruit IPM Report 4-24-2015

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Peach

Brown Rot: Blossom infections from the brown rot fungus can occur whenever pistils are exposed and a favorable climate exists. Infections can occur during any wetting period when temperatures are between 41 and 86°F. However optimum conditions for infection occur with wetting and temperatures in the mid 70’s. During long wetting periods (several days or more) blossoms can be infected regardless of temperature. Generally infections that occur when conditions are sub optimal are less severe. Blossoms and fruitlets will remain susceptible until the pistil desiccates (sometime between petal fall and shuck split).

Petal Fall Insect Complex: An OFM biofix was set in southern counties on 4/20. Treatments for the first flight will be due at 170-200 degree days after the first trap captures or “biofix.” This timing usually coincides with late petal fall to shuck split. Be sure all petals are off before applying insecticides. Imidan, Lannate, and synthetic pyrethroids (Asana, Ambush/Pounce, Danitol, Mustang/ Mustang Maxx, Warrior, Baythroid) are rated for control of petal fall insect pests. Diamide and diamide mixes are also labeled, and include Altacor, Belt, Voliam Flexi and Voliam Express, Belt and Tourismo, and the new diamide, Exirel. When used alone the diamides are only effective against Leps. such as OFM. Exirel is a second generation diamide and will also control PC, but must be used at the higher rate to do so. This makes it expensive to use. The spinosyn, Delegate is effective for OFM and other Leps, and thrips if they are present in nectarines. Experience has shown that the pyrethroids may be weak at lower rates against plum curculio (PC), especially in hot weather. If using any of the pyrethroids, use a high rate in order to control both OFM and PC. Rotate pyrethroids (IRAC group 3) and O.P.’s (IRAC group 1B) with different chemistries for resistance management. The key arthropod targets at petal fall are OFM, PC and various catfacing insects, primarily tarnished plant bug and native stinkbugs.
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