Commercial Peach-Nectarine Insect and Disease Control

Commercial Peach-Nectarine Insect and Disease Control 2020

In the following table, the quantity of materials to use to apply to peaches and nectarines is given as amount per acre, which is the amount of spray volume needed to cover one acre of well pruned, standard size trees. Determine the amount of water being used per acre on your trees then add the rate of the chemical listed below in the rate/acre column to the amount of water. Always read the label carefully for any restrictions or changes — THE LABEL IS THE LAW. In Oklahoma, applications are commonly made using 20 to 150 gallons per acre. How effective this range in spray volumes will be is determined by several factors including: tree sizes, tree densities, canopy density, and type of nozzles. Air blast sprayers normally require amounts on the higher end of this scale. Irrespective of the amount of liquid per acre applied; use the amount of chemical per acre as a guide for mixing.

 

Table 1. Quantity of materials to use to apply to peaches and nectarines.

 

 

 

^r Restricted Use Pesticide. Must have a pesticide applicator’s license to apply.

^OMRI Organic Material Review Institute (OMRI) listed for organic production.
¹ Do not apply during periods of high temperature or injury to foliage may occur.
² Do not apply more than 3.0 pounds active ingredient per acre per season.
* Cidetrak pheromone dispensers may be used for oriental fruit moth (OFM) control, but must be attached to trees before first adult flight. See Oriental Fruit Moth below for more discussion on the method.
Chemical group classifications can be found at the following Web sites: Herbicides-http://www.plantprotection.org/hrac/; Insecticides-http://www.irac-online.org/; and Fungicides-http://www.frac.info/.

 

READ ALL LABELS for important restrictions or warnings about tank mix compatibility or phytotoxicity before applying pesticides. THE LABEL IS THE LAW.

 

 

Bee Protection Precautions:

Several insecticides listed are toxic to bees. Read and follow individual labels for specific bee protection measures for each product. Do not make insecticide applications during the blooming period for the preservation of pollinator populations, including bees. In addition, close attention should be paid at other times to the blooming of cover crops or weeds on the orchard floor. If weeds or cover crops are blooming, mow the orchard floor before application of pesticides.

 

Greater & Lesser Peachtree Borer Control:

In mid-May, apply 3 quarts Lorsban 4E in 100 gallons of water to trunks. Spray the trunks thoroughly from the large branches to the ground line (1.5 to 2 feet). Do not spray the fruit or leaves with Lorsban. Asana XL - Apply as directed trunk and scaffold limb spray. Thorough coverage of trunk and scaffold limbs is required. Do not spray the foliage.

Asana XL or Warrior II applications in September are also effective in controlling Lesser Peachtree Borer.
Lorsban 4E may also be used as a preplant dip application for nonbearing peach trees at the equivalent application rate of 3 qts/100 gallons of water. Dip trees several inches above the grafting bud scar and plant immediately.

 

Peach Twig Borer:

Bloom time applications of Bacillus thuringiensis (B.t.) or Entrust for peach twig borer in combination with treatments for brown rot can help in cutting application costs. Pay attention to spray timing to avoid foraging bees and other pollinators. Also, dormant season applications of oil plus an insecticide like Dimilin, Entrust or Delegate can seriously reduce infestations of peach twig borer.

 

Oriental Fruit Moth:

The earliest indication of injury by this insect is similar to that of the peach twig borer and consists of a “dying-back” of new growth in the spring. The worms found burrowing in the twigs are pinkish or creamy-white with brown heads. One larvae/10 terminals/tree should be considered an economic infestation. Later generations of the worm enter the fruit near the stem before the fruit ripens. The fruit may look perfect at the time of harvest, but breaks down shortly after packing.

Mating Disruption Strategy

Mating disruption is an alternate method of Oriental fruit moth control. Trece, Inc. has the Cidetrak OFM-L system which disrupts the normal mating communication between adult male and female moths, reduces fertile egg laying, suppresses larval infestation, and reduces the need for insecticide application. Application of the Cidetrak systems calls for a minimum of 100 dispensers per acre or no more than 200 dispensers per acre per year. These dispensers are attached to lateral branches in the upper one-third of the tree canopy. Dispensers are applied 2-3 days after trap capture of the first male moth using pherocon 1C traps. If the cropping season goes beyond 120 days, a second application should be made. For maximum effectiveness, remove and destroy infested fruit from trees and the orchard floor. Growers electing to use this strategy to manage OFM should monitor carefully around external sources of infestation that are not treated with the Cidetrak, and should be prepared to treat with insecticides if infestations coming from these outside sources are too extensive.

 

Plum Curculio:

Early detection of this important pest should be conducted using pyramid or screen traps to monitor for adult weevils. The construction and utility of these traps for this purpose are outlined in OSU Fact Sheet EPP-7190 - “Monitoring Adult Weevil Populations in Pecan and Fruit Trees in Oklahoma.”

 

Bacterial Spot:

The disease attacks the leaves, fruits and stems. There is a varietal difference in susceptibility. The best defense against bacterial spot is to plant resistant varieties. See Fact Sheet HLA-6210 for resistant varieties that grow well in Oklahoma.
For detailed information on using pesticides safely, see Extension Fact Sheet EPP-7450, “Pesticides Can Be Used Safely,” and Extension Fact Sheet EPP-7457, “Toxicity of Pesticides.”

 

 

 

^r Restricted Use Pesticide. Must have a pesticide applicator’s license to apply.
^OMRI Organic Materials Review Institute (OMRI) listed for organic production.
* REI = Re-entry interval. Same for both peaches and nectarines unless otherwise noted.
**PHI = Pre-Harvest Interval – number of days required from last application to harvest. PHI same for both peaches and nectarines unless otherwise noted.
*** Rovral may not be applied after petal fall
N/A = These fungicides may not be applied after shuck split.
Chemical classifications can be found at the following Web sites: Herbicides-http://www.plantprotection.org/hrac/; Insecticides-http://www.irac-online.org/; and Fungi-cides-http://www.frac.info/.

 

 

Becky Carroll

Associate Extension Specialist

Fruit and Pecans

 

Phil Mulder

Professor and Department Head

Entolmology and Plant Pathology

 

Brenda Sanders
Horticultural Communications