Tree Fruit IPM Report for May 18. 2023

Peach:

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. Dr. Lalancette has published a handy guide for copper applications in early covers. Antibiotics such as Mycoshield or Fireline may also be used and may offer slightly more residual activity during long wetting periods. Bacterial Spot leaf symptoms have began appearing in southern county orchard during the week of 5/8. These infections probably occurred mostly during the heavy rains that occurred on 4/30-5/1. Fruit symptoms from this set of infections should begin appearing soon. This week no increase in symptoms was noted.

Oriental Fruit Moth: A biofix point for OFM was set on 4/10 in both northern and southern counties.  All timings for first generation OFM have past. Second generation timings are updated below:

Plum Curculio; Tarnished Plant Bugs; and Other Catfacing Insects: Plum Curculio start to move into orchards at about 88-100 degree days base 50 after January 1. Applications for PC should be initiated once all petals are off, with a second application made with ovicidal materials at 379-402 DD. Currently we have accumulated about 425 DD base 50 in southern counties, and 366 DD base 50 in northern counties. Growers can monitor degree day development at their site by finding the nearest weather station and using the degree day development tool at NEWA. Catfacing insects are starting activity, but will become more of an issue as temperatures warm and mowing and other ground cover activities become more common.

Scale Insects: White peach scale crawlers have not yet emerged but usually begin emergence about the third week of May and continue emergence until about the middle of June. San jose scale crawlers typically begin emergence about late May or early June and continue emergence for up to 6 weeks. Control options during crawler emergence include Neonicitiniods (suppression only), and the IGR’s Esteem and Centaur. See the NJ Commercial Tree Fruit Production Guide and the product labels for more information.

Apples and Pears:

Diseases: Now that primary scab is nearing the end, or has ended, the focus turns toward summer diseases such as fruit rots (esp. Bitter rot), and sooty blotch and fly speck. Bitter rot control has been difficult at best in recent years even where management programs have been rigorous. Research has suggested Products such as Merivon, Luna Sensation and Inspire Super may be effective, and longtime reliable broad spectrum fungicides such as captan and ziram should provide control. Experience has suggested that the addition of phosphorous acid products such as Prophyt or Rampart to captan sprays may improve control. Observations are that phosphorous acid products improve control of other summer diseases such as sooty blotch and flyspeck, and may help suppress scab infections where present.

Fire Blight: Infections can still occur post bloom so covers with antibiotics when infection events are forecast using the NEWA fire blight model may be beneficial. Remember to rotate streptomycin and oxytetracycline products. Fire Blight symptoms began appearing in southern county apple and pear orchards the week of 5/1. Typically it is recommended to cut out infected limbs however this is a practical decision that must be made. This blog post from Michigan State may be helpful to decide whether it is worth cutting out infected tissue.

Codling Moth (CM): The first codling moth flight has started. A biofix was set for CM on April 17^th in both northern and southern counties. Treatment timings are updated below:

Pear:  Second generation pear psylla began hatching about 5/15 in southern counties. Options for control include spynosyn products such as Delegate and Entrust, and the neocitinoids (IRAC group 4A). The addition of 0.25-1 gal of summer oil may improve control. Other options include Movento, and products containing abamectin. Be sure to read and follow the label instructions regarding the addition of penetrants for these products.

Tree Fruit Trap Captures – Southern Counties

Tree Fruit Trap Captures – Northern Counties

Phenology Table: Based on annual observations made in Gloucester County.