Early rot has already been reported on Early Blacks and Stevens. This fruit rot disease is one of the first to be observed during the growing season. Infected fruit have brown-dark brown spots with concentric rings and as infection progresses, black, pimple-like structure (pycnidia) may be visible on the fruit surface.
Cranberry IPM Message
We have gotten a few calls about gypsy moth. There is no recommendation to treat for the moths that folks are reporting (both brown moths and white moths); IPM recommendations target larval stages. To the best of our knowledge, gypsy moth has only one generation per year, contrary to some information going around in the rumor mill. You may see dead caterpillars on tree trunks.
Altacor and Delegate are still your best choices for cranberry fruitworm control with respect to residual and bee safety compared to Diazinon, so we recommend using those products over Diazinon. If you are concerned about sprays going out in unstable weather pattern, Altacor should have good residual and rainfastness. Please use the traditional cranberry fruitworm timing for Howes, spraying...
Please let the Entomology lab know if you have a scale problem or if you think you have a problem. They can help you diagnose it and they want to know how much is out there. Timing for good control is critical so do not wait too long or try to time with other sprays; just go out and get it done.
Please let the Entomology lab know if you have a scale problem or if you think you have a problem. They can help you diagnose it and they want to know how much is out there in the industry. If you have scale, it is time to spray. As far as fruit rot, it is also time to be putting out first fungicide.
Now is the time to be monitoring for scale. Check the June 5 newsletter for more info. Bring samples into the Entomology lab for confirmation. Treatments should be going on in the next 2 weeks. If you are using pheromone traps to time sprays for BHF, Spag or girdler, traps should be out.
Many growers have been treating with Avaunt over the past few weeks for winter moth or weevil. Winter moth should be finishing up so it's is time to stop chasing. Weevil has been reported over threshold and it should be treated if you have high numbers. Spag is out and larvae are getting picked up in sweep nets now. We had also heard of high counts (8 larvae) of black-headed fireworm.
We have heard of very high counts of gypsy moth over the past week. If weevil is not in the mix, Delegate is a good choice for the cutworm pests, as is Intrepid. Sevin can also be a good choice if your caterpillars are dominated by gypsy moths. Humped green fruitworm has also be scouted.
Winter moth larvae are out and growers are spraying to control the immatures. We sprayed Rocky Pond bog in Miles Standish Forest on Monday for WM control. The larvae are very small; using a hand lens or other magnifier to see them, if needed (see pictures on first page of May 1 newsletter).
Frost season is underway! As of April 23rd, most bogs had reached white bud stage. Some bogs that iced-out late were lagging behind a bit. Starting on April 27th and updated as the plants advance, photos of tolerance stages will be posted on the Station website.
