Are spider mites poised to infest your soybean fields? With drought conditions persisting across Ontario, Huron Commodities agronomist Wayne Wheeler says “it’s not a case of whether spider mites will show up, but when.”
In this episode of Real Agriculture Soybean School, Wheeler explains that one of the major attractions for spider mites are well-groomed areas surrounding fields. “It seems like the nicer you cut the grass, the more you get damage in those areas. A lot of times they move in off really nicely manicured lawns.”
Spider mites are microscopic insects about the size of a grain of sand. When they do show up, Wheeler says the crop tends to turn a reddish or bronze colour. “You might need a hand lens to see them, but if you flip over to the back of the leaves, you’ll see these tiny insects moving around.
Diligent scouting, beginning in the first week of July, can help growers take a bite out of spider mites. According to OMAFRA field crop guidelines, control is required if you find four or more mites per leaf or one severely damaged leaf per plant prior to pod fill. Spraying the perimeter of the field with an insecticide will stop them, says Wheeler.
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