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Cranberry IPM Message

We had our first report of early rot late last week (July 22).  This is caused by the fungus, Phyllosticta.  Remember that resistance development to Abound, Indar, and Proline is a real and serious threat.  Applications of these fungicides should be made PRE infection rather than POST infection (now).  For RM purposes, it is best to use multi-site contact fungicides, like chlorothalonil or...

If your fruit have set, you are clear to make applications of Select/Select Max.  With any herbicide or pesticide for that matter, exercise caution when applying in hot conditions.  The general guideline is that the risk for vine injury increases if the temperature (degrees F) and humidity exceed 150.

Several calls have come in about wilting, watering and daytime cooling.  In most instances, it is too early to be doing mid-day cooling.  That is really only needed when fruit are present.  Otherwise, assuming you have been keeping up with the water needs of your plants, they should be able to cool themselves without needing additional irrigation during the day.  If you have not been...

Growers should be aware that there have been instances of drought stress damage reported in the region.  New, tender growth on cranberry can be very prone to heat and drought damage.  Such damage may be more pronounced this spring because of recent weather conditions of high vine level temperatures, little or no rain, low dew points, and windy conditions.  In addition, saturated soils early in...

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.

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.