By Dr. Henry Wu, Technical Sales Support Representative, Chemtura AgroSolutions
The end of the 2012 growing season may be in sight for grape growers, but spider mites may not have gotten the memo.
Vines are still vulnerable to mite flare-ups, so remain on the look out for spiking mite populations, especially if the weather stays warm. Check spots in vineyards where mites have historically been a problem, and be sure to monitor any dry areas where vines are stressed.
It’s important to protect vines now so that they are healthy and productive next season.
Of course, preharvest and reentry intervals are vitally important this time of the year. Therefore, control tools like Acramite® 50WS from Chemtura AgroSolutions with its preharvest interval of 14 days and reentry interval of only 12 hours, combined with its powerful knockdown of key mite species, offers an excellent solution.
Monitor sour rot and Botrytis, too
It’s also important to be on the look out for sour rot in some grape varieties.
According to researchers at the University of California, as berries ripen and sugar content exceeds 8%, injured fruit become increasingly susceptible to invasion by a wide variety of naturally occurring fungi. Invasion occurs at the point of injury caused by insect or bird feeding, mechanical or growth cracks, or lesions resulting from powdery mildew or black measles. The resulting rot can be severe as it progresses beyond the original injury.
Control options are somewhat limited; some growers use hand crews to cut out the worst clusters. Otherwise, copper-sulfur dust may be an option to slow the spread of the disease.
And don’t forget about Botrytis. While generally more of an issue earlier in the season, pre-harvest rains can re-ingnite this disease.
Viticure® fungicide is a systemic sterol inhibitor fungicide with a short seven-day preharvest interval that can clean up any late powdery mildew and suppress Botrytis, too.
Growers have full plates this time of year, and what’s going on with vines may not always be top-of-mind. That’s why it’s so important to develop trusted relationships with PCAs and other key advisors to ensure crops are protected and ready for next year’s production.