Insects. Second fruitworm applications are currently going out on many bogs this week or have already been applied. Chlorantraniliprole is still the compound of choice. There are multiple products and formulations available. The rates differ, so be sure to read the label of whatever you are using carefully! For example, Altacor eVo or Osaria Ultra 70WDG can go on 2 times at 2.2 oz, while the rate of Turazi is 4.5 oz. Methoxyfenozide (Intrepid or Inspirato) is another choice for fruitworm management during bloom. Delegate is very expensive and best saved for later this month, if at all.
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. Please wait until bloom is complete and bees have been removed.
Disease. Many growers have already applied their 3rd or even 4th fruit rot fungicide! We have had more and more reports from growers that they are seeing rapid bloom progression on some varieties, and that the traditional 7–10-day intervals between fruit rot applications are too long to capture all the bloom.
Foliar applications for phytophthora (e.g. Rampart, Fungi-phite, Phostrol) can be a good mix with Altacor or a late fruit rot fungicide. However, do not mix with coppers. Most labels recommend at least a 20-day interval between use of a copper and phosphorus acid to avoid copper toxicity.
Symptoms of Tobacco Streak Virus and Blueberry Shock Virus (TSV and BlShV) are already showing up on Stevens and BG berries, with red and brown blotching (see photo). Do not be fooled into thinking it is fruitworm damage. There is no treatment for viruses.
Weeds. As the cranberry bloom period comes to an end, growers are now thinking about postemergence herbicides. These include popular compounds like clethodim (Select Max/Intensity One, etc.), mesotrione (Callisto/Explorer, etc.) and for some growers quinclorac (QuinStar), too.
Poverty grass is at an active growth stage, so this is the best time to apply a grass herbicide for maximum efficacy. If you can treat it at least twice, you will get better control. Repeat applications need to be at least 14 days apart and there is a 30-day PHI for clethodim products (and an even longer 60-day PHI for Poast which contains sethoxydim).
Remember to ALWAYS include a surfactant with your grass herbicide – it is needed for these types of herbicides to work. Use 1-4 pt/A of NIS or LI 700 for chemigation applications. If you are using another method to spray (like a drone) that uses less water, the amount of adjuvant will be a percentage of the final spray volume (not a rate on an acre’s basis) and this info can be found on the pesticide label.
You can apply up to two applications of mesotrione (Callisto) per year. If you have not already made an application and want to squeeze in two postemergence apps, remember that apps need to be at least 14 days apart and there is a 45-day PHI.