Fruit IPM for 6/17/20

Peach:

Oriental Fruit Moth: We are between generations 1 and 2, with the first insecticide applications due in southern counties by the end of the week, and in northern counties by the end of the following week.

See timings below:

Tarnished Plant Bugs and Other Catfacing Insects:  Catfacing insect pressure has begun to increase in southern counties where groundcover management is poor. In addition BMSB was noted in beating tray samples in one Gloucester county orchard. Populations are very low but this demonstrates that adults are present in orchard environments.

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. The number of orchards with foliar bacterial spot  has increased over the past week, however the numbers are still very low. We are now at pit hardening, so the fruit has some resistance to infection.

Brown Rot: Maintain coverage with effective materials until pit hardening. Do not rely on sulfur alone unless a dry weather pattern develops.

Apple:

Codling Moth (CM): We are between generations 1 and 2 throughout the state, and pest pressure is very low in most orchards. Low pest pressure is indicated by pheromone trap captures that are below 5 male moths per trap. No insecticides are needed in these cases. There are 2 locations in northern counties with 6-13 moths per trap, which prove the exception, and do need to continue treatments.

Green Aphid Complex: Green Apple Aphids and Spirea Aphids are increasing on tree terminals in a number of orchards. Populations have increased to over 50% of terminals infested in some northern locations. If over 50% of terminals are infested with healthy colonies, then treatments are justified. If your orchard ground cover is pure grass with no flowering weeds, then there is nothing that bees can forage on, and you can use the most effective sucking insect insecticides without harming the bees (that aren’t there). See the 2020 Tree Fruit Production Guide table 4.2 on page 117 for a list of materials effective for sucking insects, including aphids. Agri-Flex, Admire, Actara, Belay, Endigo, Leverage, and VoliamFlexi have bee warning labels and are especially toxic to bees. Therefore it is against the label if you apply these materials when flowering weeds, and therefore bees are present. If 20% of the infested shoots have beneficial insects present, treatment is not recommended.

Tufted Apple Budmoth (TABM): A biofix was set statewide on May 6. In southern counties, we are in the middle of insecticide timing for TABM, with the last treatments due about June 25. In northern counties the next treatments are due on June 19 through June 20.

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): Trap captures are starting to increase as ‘Duke’ starts to harvest and ‘Bluecrop’ starts to turn. The best insecticide choices include any pyrethroid (Asana, Brigade/Bifenture, Danitol, Mustang, Hero), Imidan, Delegate, Assail but not other neonics, Lannate, Malathion ,and Exirel and Verdepryn. Assail is not suggested as populations increase.

Aphids: Aphid infestation levels stabilized over the past week, with some decreases where populations were treated. Our averages were  just over 4% of terminals (mostly new canes) infested, with a high of 76% on the lower shoots. Some aphid materials such as Actara and Movento can be effective for scale (see below), but these are not effective for SWD.

Putnam Scale: Scale crawlers have been active over the last couple of weeks. Growers should take note if any berries have scale on them (see Figure 1), and which fields they come from. There are practically no scale insecticides that also control SWD. The one exception is Diazinon, but that can be only used once per season and has a 7 day PHI. Coverage is also key, so ground applications are required for adequate scale crawler control. Since this insect has 2 generations per year, it is wiser to note the fields that will need treatments and plan on treating those fields in early August when the second generation crawlers are active.

Figure 1. Putnam scale recently settled on ripening fruit. Photo – Carrie Denson.

Oriental Beetle (OB): Oriental Beetle adults started to emerge last week. Most trap captures as of this writing are now over 100 adults per trap. These insects are now mating and laying eggs. Any grower who has fields with significant populations should be treating for this insect with either Admire or mating disruption (which should already be placed on the bushes). There is a 7 day PHI for Admire use, and treatments must be applied prior to mid-July.

By the Numbers:

Grapes:

Grapes are at or past full bloom in southern counties. Bloom sprays are critical for disease control. Targets at bloom include: Botrytis; Powdery Mildew; Downy Mildew; Black Rot; and Anthracnose. A helpful discussion of disease management at bloom can be found at the Penn State Wine & Grapes U. You can also find suggestions on Mizuho Nita’s grape blog, and in the Rutgers Grape Production Guide.