Borers, Rots, Codling Moth and Leafhoppers
Peach:
Lesser Peachtree Borer and Peachtree Borer: With the few fruit left on the trees in northern counties, there is not much going on except for the borer application that still needs to be applied.
There are a number of pyrethroids that are labeled for borer control in addition to the conventional application of Lorsban. The most critical elements of successful control are 1) Timing and 2) Spray Volume. Peachtree borer (PTB) has 1 generation per year, while lesser peachtree borer (LPTB) has 2 generations per year. They both lay eggs on the wood, followed by hatch and the larvae boring in the cambium layer of wood. LPTB is found on the branches and scaffolds associated with cytospora canker, and PTB is found on the trunk a few inches above the soil line to a few inches below the soil line. PTB is not normally associated with cankers. In recent years PTB has been the main insect of concern at this time of year. Most of the emergence is now done and most of the eggs have been deposited. The control objective is to apply the insecticide as soon as possible so hatching and other already emerged but very young larvae are controlled. Spray volume is very important, since the complete lower tree trunk and ground around it has to be saturated and well covered, as well as any cankers on scaffold limbs. Usually this can only be done dilute with a handgun. Growers normally wait until after harvest, since Lorsban cannot contact unharvested fruit. The timing is now, so waiting until later will make controls much less effective.
Apple:
Codling Moth (CM): Codling moth continues to cause problems on a number of farms. High populations are present in both northern and southern counties. Treatments must be maintained as long as populations are high. Any site with a trap count that exceeds 5 males per trap is considered above treatment threshold. Effective materials that can be used up to 7 days PHI include Altacor (5), Baythroid (or generic cyfluthrin), Leverage (has Baythroid in it), and Delegate.
Rots and Bitter Rot in particular: Bitter rot and other rots are still problematic. All covers should include Captan and/or Ziram. Frequent covers may be necessary in our current wet weather pattern. The addition of Pristine (14.5-15 oz/A), although a higher cost, will help bitter rot control. Flint (14 Day PHI) and Sovran (30 day PHI) can also be used for tot control, but are more effective on white rot and black rot that on bitter rot. Remember that Ziram has a 14 day PHI; Captan and Pristine are for all practical purposes 1 day PHI, when allowing for the manual contact of picking.
Tree Fruit Trap Counts – Southern Counties – August
| Week Ending | STLM | TABM-A | CM | OFM-A | DWB | OFM-P | TABM-P | LPTB | PTB |
| 8/5 | 18 | 3 | 10 | 19 | 12 | 1 | 1 | 4 | 5 |
| 8/12 | 30 | 2 | 20 | 35 | 8 | 1 | 0 | 24 | 11 |
| 8/19 | 12 | 1 | 11 | 10 | 14 | 2 | 0 | 28 | 12 |
Tree Fruit Trap Counts – Northern Counties – August
| Week Ending | STLM | TABM-A | CM | OFM-A | DWB | OBLR | OFM-P | TABM-P | LPTB | PTB |
| 8/5 | 67 | 1.1 | 6.3 | 2.3 | 7.9 | 6.5 | 2.8 | 0.8 | 4.5 | 5.8 |
| 8/12 | 29 | 1.6 | 5.9 | 2.4 | 3.8 | 1.5 | 2.9 | 1.2 | 3.3 | 7.3 |
| 8/19 | 30 | 2.2 | 5.6 | 2.5 | 7 | 2 | 3.6 | 1.8 | 8.2 | 5.3 |
| 8/26 | 28 | 4.1 | 5.3 | 2.2 | 3 | 2.5 | 4.2 | 1 | 24.4 | 5.4 |
Blueberry
Sharpnosed Leafhopper: Our trap captures of adult leafhoppers finally increased over the past week. However, this was only in Atlantic County, which has had higher levels than in Burlington County. Given the increase (see graph below), it is now time to apply your second generation leafhopper insecticides. The motile forms, or adults, must be controlled in order to prevent the spread of Stunt disease in cultivated fields. The most effective SNLH materials include Actara, Assail, Admire, Diazinon (only if you have not yet used it), and Imidan. Lannate and pyrethroids can also be used (Asana, Bifenture/Brigade, and Hero), but are not quite as effective.
