Fruit IPM for 7/17/19

Peach:

Oriental Fruit Moth: Treatments for the 3^rd generation OFM are timed for now and over the next week, depending on which county you are in.

Populations on most farms are low, but if trap captures exceed 6 moths per trap, then treatments are justified. See timings in the table below:

Brown Rot: Most growers should be relying on a captan based program for mid-season covers, followed by better materials during the last 3 weeks pre harvest. Extreme heat is forecast for the end of the week. Extreme heat may damage if rains follow soon after. Do not spray captan or sulfur if temperatures are above 85-90 deg F. See Dr.Lalancette’s recent article in the Plant and Pest advisory for more information.

Apple:

Rots/Summer Diseases: The following is an edited version from what appeared in the newsletter the previous week: Once again bitter rot is appearing in highly susceptible varieties such as honeycrisp and empire in southern counties. Mid-Atlantic researchers looking at improving bitter rot control are focusing on bloom and early covers as critical times for control. Because the symptoms do not appear until long after the infection; and pinning down when infections occur can be difficult. Nothing can be done to stop infections which have already occurred but have not yet shown symptoms. Going forward there are several considerations for preventing further infections. If you will be hand thinning, removing infected fruit and either removing them from the orchard or placing them in row middles and chopping them up will help to reduce inoculum present in the canopy. Where dead shoots are present from fire blight or any other cause, prune them out to reduce inoculum buildup. Maintain good coverage with captan at high rates. The addition of a phosphite material to captan may improve control of all summer diseases. Avoid potassium phosphite materials on Honeycrisp as potassium may contribute to bitter pit problems. Merivon (FRAC 7+11) with a 0 day PHI for pome fruit, has been shown to have good efficacy against all summer diseases including bitter rot. Luna Sensation (FRAC 7+11) is also labeled for bitter rot control, has a 14 day PHI for pome fruits, but may not be as effective as Merivon. Combination materials that contain Qol inhibitors (the “strobin” materials, including Merivon and Luna Sensation), are also effective for white and black rot.  Researchers in Pennsylvania are reporting that the fungicide Omega (FRAC 29) (fluazinam) looks good in lab trials for bitter rot, and that Topsin-M (FRAC 1) may have some efficacy. However, this material was not effective in research trials in NY. Be aware that Omega has a 28 day PHI and may be weak for white rot.  Therefore possible programs include for the second half of the season: Captan plus Merivon, or Captan alone at the high rate, or Captan + Omega (if greater than 28 days PHI). Extreme heat is forecast for the rest of this week. Hot weather can cause sunburn on exposed fruit and invite rot pathogens. Applications of Surround at 25-50#/ac can help protect exposed fruit against damaging heat.

Codling Moth (CM): The timings are updated below for second generation CM. Trap counts and emergence are still very low. Therefore if you have applied your 2^nd generation insecticides, and your trap counts are less than 5 moths per trap, additional treatments are not needed.

Grapes:

Grape Berry Moth (GRB): Treatments for the third generation were timed for July 14-15 with Intrepid or Altacor. Those southern county growers who did not treat but have seen problems, should do so with standard insecticides as soon as possible. The treatment window will be closed by the end of the week.

Grape Trap Counts

Tree  Fruit Trap Counts – Southern Counties

Tree  Fruit Trap Counts – Northern Counties

Blueberry

Spotted Wing Drosophila (SWD): For the past 2-3 weeks our traps have shown a marked increase in adult activity.  SWD pressure is very high. At this time of the year several generations overlap, and the adult target represents only a small portion of the population, comprising only 8-10% of the total population. Since it is the principle target for insecticide sprays, it helps illustrate why repeated applications at close intervals are required for maggot free fruit. Make sure to stay on a 6-7 day program for ANY field that yet to be picked, including machine picking for processing fruit. Elliott and other late varieties need to stay on a strict schedule. Some growers are border spraying next to fields that have already been picked, which is not a bad idea. An Elliott field which is surrounded by Bluecrop fields with fruit left on the ground from the picking machines, will be under A LOT of SWD pressure.

Oriental Beetle (OB): Adult populations have started to drop, indicating that most egg laying  is also slowing down. By this time of year the first emerged larvae will soon start to molt into 3^rd instars, which are not susceptible to imidacloprid/Admire. Therefore if you haven’t yet treated for this pest, and still intend to do that, the window for effective control closes this week.

Aphids: Aphid infestations have increased some since last week, mainly in Elliott plantings. Colony size average 5-10 aphids per infested shoot.

Blueberry Traps

Atlantic County Traps

Burlington County Traps