This week, we've received a few more reports and samples of cranberry wilt. Cranberry wilt, often followed by tissue browning, is caused by water stress and since new growth is much more prone to desiccation, it is commonly observed during spring.
Cranberry IPM Message
Bloom is coming on slowly in some areas. With mixed varieties, time the start of fungicides with the earlies. Since we are in that situation, we will be applying our first fungicide today. Our program will consist of 2 applications of Proline and the third as Bravo. All at the full rate. Recent sweeps yielded a few weevils, span worms, and large gypsy moths. None over threshold. We have...
Just a clarification: Delegate and Altacor are still the best choices for Spag. We had heard of a report where Spag were not well controlled with a Delegate application and we were speculating that it may have been due to the size of the larvae. Further information may be indicating that the application may not have been up to par.
Spag is over threshold in many locations. In some cases, larvae may be too big to get expected control with Altacor or Delegate. It is too late for Intrepid as they have achieve most of their size and will be pupating soon. Gypsy moth populations have exploded and larvae are over 1 inch long in many instances.
Cranberry weevils, in numbers of 10-20 per sweep set, were reported late last week. Be on the lookout.
If you want to apply Poast (or Select) and Callisto at the same time, you must do a ground application. Poast and Select cannot be applied by chemigation and Callisto cannot be applied by air.
Many growers are picking up gypsy moth larvae; sweep sets easily in the 10’s and 20’s. The threshold is 4.5 average per sweep set but try not to jump the gun too soon. We are still early in the season and we haven’t seen any of the early season pests yet, like cranberry weevil and cutworms.
Gypsy moth larvae, sometimes up in the 20's have been reported. Winter moth is still a concern especially if the insect has been problematic on your bog in previous years. The long string of frost nights has made application of May pesticides difficult, however we appear to be heading into a better weather window. Devrinol applications can still be safely made. Some growers are putting out...
Some early grasses are up. Growers are spraying Poast and/or Select for control of these early emerging grasses. These herbicides work best when applied before grasses flower. Be sure they are tall enough to have enough leaf area to absorb the herbicide (usually 4-8" tall is a good guide). Grass herbicides CANNOT be applied through the chemigation system. They will only control TRUE...
Dodder seedlings (~1/2” long) were reported on April 25, occurring in a bog in Rochester. Applications of Casoron for dodder control will be going out soon. Be sure to check your own bog for early emerging seedlings. We have demonstrated improved efficacy with higher rates and/or two applications of Casoron (on a bog where control was inadequate).
Now is the time to be looking (and spraying) for winter moth larvae out on the bog! Advanced bogs, hybrid cultivars, and sanded bogs will be warmer and more likely to have growth that is appealing to WM now. These bogs will likely need to be sprayed this week. Later varieties and colder areas will likely need applications next week.