A day earlier than usual because of the Friday Holiday - Happy Independence Day!
The Cranberry Station is hosting another Bogside Meeting July 14th 9-10:20. You can join the meeting by Zoom or in-person in the AD Makepeace Room at the UMass Cranberry Station (no registration required, and no credits offered).
Please contact Giverson Mupambi gmupambi[at]umass[dot]edu (gmupambi[at]umass[dot]edu) if you would like to attend by Zoom.
We have observed and been hearing reports of some beds experiencing patches of “heat blast” – tender new growth getting desiccated and looking burned. Areas that have been sanded, bed edges, spots of thin vine with poorly developed canopy, and other scenarios where vines can be hotter and have less access to soil moisture can be prone to these symptoms. The areas we have been hearing about are on super hybrids (Mullica, Haines). Pay special attention to your dry spots, especially now with developing fruit out there.
Insects
Altacor, Altacor, Altacor! Timing for your cranberry fruitworm spray is NOW! Be aware that the new formulation, Altacor eVo, is more concentrated and uses a rate lower than the older formulation of Altacor (2.2 oz/A of eVo vs 4.5 oz/A older formulation). Two Altacor sprays (back-to-back, min. 7-day interval between applications, but 10-14 days are better) are recommended. If you feel you have heavy cranberry fruitworm or sparganothis fruitworm pressure, additional sprays could be Intrepid followed by Delegate at the end of the month.
The summer generation of cranberry weevil is active now, particularly on the super hybrids. Be aware that the only option for management is Actara which is extremely toxic to bees and should NOT be applied if bees are still working the bloom. Fanfare may be an option if you are a domestic grower and your handler allows a second application, but Fanfare is also extremely toxic to bees.
Disease
Many growers have already applied their third fruit rot fungicide. Due to the “Poor” Keeping Quality Forecast, a fourth fungicide application is advised.
While the recent focus of pathology management has been fruit rot, if you have a bog diagnosed with phytophthora root rot this can be an ideal time to treat for phytophthora (after improving your drainage). You can apply phosphonates or soil phenylamides when soil temperatures are conducive for root development and pathogen multiplication (June, July and August). We have had some questions from growers about tank mixing fungicides used to control phytophthora with the fruit rot fungicides. We asked our colleagues in New Jersey, and they report that growers there regularly mix phosphonate fungicides (like Rampart) with Quadris Top or Proline. It is unclear if there is an added boost from mixing, but it does allow growers to target both diseases with a single spray.
Weeds
Poverty grass is at an active growth stage in most locations now, and active growth periods are the best time to apply a grass herbicide (sethoydim aka Poast and clethodim products like Intensity One). If you can treat it at least twice, you will get better control. If you are choosing to wait until after bloom to apply herbicides, prepare to treat poverty grass as soon as you can before it begins to flower. Make sure to include an adjuvant.
The fireweed in our test pots has germinated and is still small enough to be susceptible to Callisto treatments. It will be too big to control in a few weeks, so if you have a history of this weed on your bogs and you did not get out a preemergence herbicide this spring, then you may want to think about a Callisto application.
Dodder is up in the cranberry canopy now and easily visible. It has not yet begun to flower (at least none that I have observed or heard of so far). If dodder is patchy on your bog, some growers have had good luck spot treating the patches with concentrated Callisto. It is much more effective to treat dodder BEFORE it flowers.
Fertilizer
Many growers applied their early-set fertilizer (made at 75% through-bloom) last week and are thinking about their late-set fertilizer (to be made at 75% out-of-bloom). The late-set application should deliver the remainder of your bed’s seasonal nitrogen needs. For example, if you planned to deliver 40 lb/A N for the year and you applied 8 lb/A at roughneck (20% of needed), another 24 lb/A N at early-set (another 60% of total needed), you will need to apply another 8 lb/A (20% of total needed) to reach your 40 lb/A N goal.
Some growers have been taking a different approach for the newer “super hybrids”. This tactic divides up the “set” fertilizers into smaller and more frequent doses. Starting with the first application at early set and then following that with 2 more applications on a 7-day schedule.
Please reach out to Peter Jeranyama peterj[at]umass[dot]edu (peterj[at]umass[dot]edu) if you have any questions regarding fertilizer rates and applications.