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IPM Message for Cranberry Growers: Jun 8, 2018

June 8, 2018

We are hosting a bogside workshop on Wednesday June 20 from 8-10 AM.  We will be discussing pest management issues of the day as well as how to collect proper vine samples for diagnosis.  We will be offering 2 contact hours for the workshop.  If the weather is inclement, we will meet by the library, otherwise we will meet bog side.

If you have pheromone traps out, you should check them at least weekly.  If your site is prone to high flights of Spag, you may need to check more often.  If you are catching more that 20 moths or so, it is usually easier to change the trap rather than pick all the moths out.  The lures should be replaced every 3-4 weeks to keep the scent plume strong. We have heard of one report of dodder growing well on a bog.  Our experience indicates that most treatments for dodder control are most effective when applied PRIOR to dodder flowering.  We are looking for sites to collect a few dodder stems, so if you have dodder, please give me or Katie a call.  We just wish to collect a sample; we will not be putting out plots or making treatments.

Depending on the varieties that you have roughneck fertilizers may have gone out already or are due to go out anytime now.  For most varieties and program, target 20% of your N at roughneck. The best available evidence indicates that cranberries respond poorly to nitrate N especially in the absence of ammonium N; the AMMONIUM FORM is recommended. Monoammonium phosphate is an excellent source but can provide excess P. Ammonium sulfate is also an excellent source. Light rates of urea, a material that breaks down to ammonium, are suitable to correct N deficiencies quickly (when the urea is dissolved and used as a foliar feed). Use blended fertilizers with ammonium N and excellent uniformity of particle size or ammoniated materials. Non-uniform blends may sort during application, giving poor results. Liquid formulations designed to be applied to the soil and taken up through the roots can be substituted for granular materials.