Fruit IPM for 6/9/20

Peach:

Oriental Fruit Moth: We are between generations 1 and 2, with the first insecticide applications due in southern counties in 10 days to 2 weeks. Where trap captures are below 8 moths per trap and no injury is present, then stretch insecticides to get as close to the model timing as possible. Where trap counts continue above 8 males per trap, then the population is too high to take this approach. This is the case in several orchards in northern counties.

See timings below:

Tarnished Plant Bugs and Other Catfacing Insects:  Catfacing insect pressure has been very low in southern and northern counties. While this is usually the other key pest complex at this time of year, low populations, along with low populations of OFM, permit skipping the insecticides or stretching the interval.

Scale Insects: White peach scale (WPS) crawlers began to emerge 5/13. San Jose scale (SJS) crawlers emerged on 5/29. If you have scale infestations on your trees, it is important to note if crawlers are present, even if you treated with oil in the early spring. If crawlers are present then treatment options include Esteem, Movento, Centaur, Venerate, and Diazinon. Esteem, Centaur, Venerate and Movento should be applied at the beginning of crawler emergence. Venerate needs to be applied at the low rate of 1 qt/A. Diazinon is labeled for only one post bloom or foliar  application on stone fruit (Rec = max. of 2 lb/acre of the 50W). The apple label allows up to 2 foliar applications per year as long as a prebloom application was not made. The peach label allows 1 foliar application per year. Foliar applications may cause russet on apples, but has worked in the field for scale crawlers as long as applications are made 1-2 weeks after the start of crawler emergence and again 2 weeks later. Belay is also effective against scale crawlers but may need more than one application during the emergence which typically lasts about 4 weeks for WPS and 6 weeks for SJS.

Bacterial Spot and Cold Injury: Some bacterial spot is still present on the leaves, but very little on the fruit. Fruit injury from bacterial spot results in dark lesions that are often accompanied by gummosis. Very little bacterial spot infected fruit have been observed in commercial blocks. However freeze damaged fruit are beginning to ooze from the pit. If you observe fruit bleeding cut into them and see if there is pit damage and/or gumming around the pit.

Rusty Spot: Rusty Spot lesions are now appearing on fruit in southern and northern counties. Rusty spot infections are ongoing until pit hardening. Maintain coverage with effective materials such as Rally, Rhyme, or potassium bicarbonate products. Other choices include Flint Extra, Inspire Super, Luna Sensation and Quadris Top, although usually at a higher cost.

Brown Rot: Maintain coverage with effective materials until pit hardening. Do not rely on sulfur alone unless a dry weather pattern develops. The Captan program, developed by Dr. Norm Lalancette would be a good program to follow, particularly as we get a little further into the growing season.

Apple:

Codling Moth (CM): The second of 2 applications for codling moth is now in southern counties and about 6/11 in Hunterdon and northern counties. Trap counts remain very low in southern counties, but are significantly higher on several farms in northern counties. See timing below:

Green Aphid Complex: Green Apple Aphids and Spirea Aphids are increasing on tree terminals in a number of orchards. These insects should be tolerated until 50% of the growing terminals have aphids. They are not a direct pest and do not vector any diseases in apples. They do serve as a food source for a number of predators, which later may be helpful for mite control. If 20% of the infested shoots have beneficial insects present, treatment is not recommended. A few locations in northern counties do have numbers which now justify treatment.

Tufted Apple Budmoth (TABM): A biofix was set statewide on May 6. The first alternate middle applications for TABM was June 3 in southern counties. This has been considered a minor pest in recent years. With the exception of Assail and Madex, most materials used for Codling Moth will control TABM.

Potato Leafhopper (PLH): PLH adults are showing up in some apple blocks. Treatment is recommended if there is fire blight present in the orchard, or for young trees. PLH can spread fire blight and stunt new growth if allowed to build to high populations.

European Red Mite (ERM): Mites are present at very low numbers in a few southern county orchards. The threshold for treatment in June is >2 mites/leaf.

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

Tree  Fruit Trap Counts – Northern Counties

Blueberry:

Spotted Wing Drosophila (SWD): Levels are low, but positive traps are getting more common. Dukes are coloring, which makes them very susceptible to SWD infestation. Insecticides applied this week need to target SWD first. The choices include any pyrethroid (Asana, Brigade/Bifenture, Danitol, Mustang, Hero), Imidan, Delegate, Assail but not other neonics, Lannate, Malathion ,and Exirel and Verdepryn.

Aphids: Aphid infestation levels have increased over the past week. Our averages were  5.1% of the lower growing terminals (mostly new canes) infested, with a high of 40% on the lower shoots.

Plum Curculio (PC): PC injured fruit are coloring prematurely and starting to drop. This is a sign of maturing larvae in the fruit. Fields with the highest PC populations have numerous dropped blue fruit, which is a good thing. While most infested fruit should be on the ground before the first Duke harvest, make sure to set your firmness sorters to kick out any soft and possibly infested fruit as an extra insurance.

Blueberry Scorch Virus and Aphids: During the middle of May scorch like symptoms were common in many fields. On May 25 we collected 14 tissue samples from different fields where bushes were showing symptoms. These were sent to the Agdia Labs on May 26 for a screening of virus possibilities. The reports received on 6/8 stated that all submitted samples were positive for Blueberry Scorch Virus (BlScV). While this does not represent all blueberry farms, it does represent all the samples we took over a wide area. Since aphids are the BlScV vector, we have to pay more attention to how they are controlled, and if possible, tolerate fewer aphids that we have in the past. For now, if you can still recognize and rogue out the infected bushes, then do so. This disease is more widely spread than we previously thought, and additional aphid controls will have to be looked at. The best materials for controlling aphids include the neonicotinoids (Class 4A): Assail, Actara, Admire; and also the related (Class 4D) Sivanto, and a Class 23 – Movento. Any other materials, for all practical purposes, are only suppressive, and not controlling. Using the correct material, in enough volume, directed at the most critical target are all important. Aphids are found in the highest numbers on the bottoms of the bushes on the tender newly developing suckers that later become the new canes. These are near the ground at the center of the bush around the crown, making them very difficult to cover. More on aphid control later.

By the Numbers:

Grape:

Grape Berry Moth (GRB): The MSU/Penn State grape berry moth model calls for setting a biofix to start degree day counts when wild grapes nearest your vineyard start to bloom. This is a very individual / local model, depending on what kind of wild grapes are near your vineyard and where you are in the State. The biofix usually falls near the middle of May, except for this year. A call from Jim Quarella on 6/3 in Landisville indicated that a couple of native and native hybrid varieties were blooming prior to any surrounding wild grapes. Indeed, of the 2 wild grape species surrounding that farm, neither was in bloom. We did find 1 wild grape area in Gloucester County well into bloom on 6/5. Given that the earliest bloom for wild or native selections was about 6/3, we are calling 6/3 the biofix date for this year in southern counties. We need 810 degree days (base 47⁰) for the start of second generation egg laying. This means that the timing for this generation if using Intrepid or a diamide insecticide should be during the first week of July. The second generation is really the first generation which can cause a problem in vineyards.