Tree Fruit IPM Report June 20, 2024

Peach:

Bacterial Spot: Fruit symptoms from this set of infections have begun to appear in southern counties. So far fruit symptoms are very low and only in highly susceptible varieties. Peaches are at or past pit hardening and fruit now has some resistance to bacterial spot. Infections can still occur but will be less unsightly and may still make grade. Growers should continue to manage using Oxytetracyclene and lower rates of copper, especially around rainy periods and severe weather.

Oriental Fruit Moth: A biofix point for OFM was set on 4/10 in both northern and southern counties.  All Treatments for the first generation have past.

Tarnished Plant Bugs; and Other Catfacing Insects: Catfacing insects are active, and activity has increased with the current weather pattern. Very little recent fruit feeding has been observed.

Thrips: If the current dry spell continues Flower Thrips may become an issue in highly colored ripening fruit, especially in poorly managed ground covers that contain clover or other flowering weeds. Thrips damage appears as “silvering” and usually appears on fruit close to harvest. If populations are high damage can be extensive. Presence of thrips may be scouted for using a beating tray to detect the presence of adults and nymphs in the tree. Flowering weeeds and shrubs on orchard edges may also be scouted by shaking flowers onto a beating tray or a sheet of paper. Delegate or Entrust at the highest labeled rate are the usual recommended materials for thrips in stone fruit. Lannate may be effective in some orchards but has not worked well in recent years. These materials all have short PHI’s and may be applied close to harvest when damage typically appears. Thrips have also been observed to mark cherries. Damage is different than peach and appears as a dark streak in a similar pattern as silvering. See the NJ Commercial Tree Fruit Production Guide for more information. Thrips activity was observed in ripening nectarines this past week in southern counties.

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, Inspire Super, and Aprovia may be effective, and longtime reliable broad spectrum fungicides such as omega, 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 these products improve control of other summer diseases such as sooty blotch and flyspeck, and may help suppress scab infections where present.

Fire Blight: Fire Blight symptoms began appearing in southern county apple and pear orchards the week of 5/20, and in northern counties the week of 5/13. 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. Once the terminal buds set, typically in July, infected wood should be removed to prevent colonization by the bitter rot pathogen.

Codling Moth (CM): The first generation codling moth timings have ended. Trap captures Continue and increased in some southern county orchards this week. A biofix was set for CM on April 17^th in both northern and southern counties. Second generation timings are updated below. Rimon is not recommended for this and later generations. The model is predicting applications earlier than normal. In southern counties it appears to be ahead of observed pest development in the field. Trap captures have bottomed out and larvae have only started to emerge from infested fruit. Growers should still follow model predictions but be aware additional treatments may be required should the next flight start later and last longer than predicted.

Wooly Apple Aphid (WAA); Green Apple (Spirea) Aphids (GAA): GAA colonies are still present in some apple blocks. GAA is generally a pest that can be tolerated since they do little direct damage. Treatment thresholds for GAA are if 50% of the shoots are infested with no beneficial insects present. WAA aerial colonies are also beginning to form in southern counties. This is about a month earlier than usually observed. In most years these are controlled by beneficials however in some years like 2022, serious outbreaks can occur. The best control for WAA is Movento applied before or when the first colonies appear. Diazinon is also effective at knocking down infestations. Movento will also control GAA and should control san jose scale when applied in mid-May, and suppress scale when applied in late May or early June.  Do not combine diazinon, oil, or oil based penetrants with Captan.

Pear Third generation pear psylla began hatching about June 8. 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, the IGR’s Esteem and Centaur, and products containing abamectin. Be sure to read and follow the label instructions regarding the addition of penetrants for abamectin products, and movento. Pear Psylla are still actively laying eggs and nymphs continue to hatch, although activity appears to be waning.

Grape: Early blooming native grapes were at trace bloom on 5/24, therefore we have set the the Grape Berry Moth biofix at 5/24 for southern counties. Since V. riparia typically blooms with early natives we used Concord and Ives to set the biofix. The model works best when growers record their own bloom dates and use the Grape Berry Moth model at NEWA. Applications for GBM using Intrepid or Diamides should be made at 810 DD base 47. Other effective materials can be applied a few days later. Applications have been historically made around the end of June in southern counties. As for diseases we are seeing low levels of phomopsis on older leaves in some vineyards. In untreated vineyards downy mildew symptoms are starting to appear. If you are not seeing downy mildew you have done a good job so far.

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

Tree Fruit Trap Captures – Southern Counties

Tree Fruit Trap Captures – Northern Counties