By Michael Donahoe
stinkbug damage – Ronald Smith, Auburn University,
Cotton is maturing rapidly across the Panhandle and it’s shaping up to be one of the earliest harvest seasons in recent years. This is due for the most part to the dry weather and the high number of heat units accumulated this summer. Some early planted fields will be ready to defoliate within the next two weeks. However, some of the later fields still have young bolls that may need to be protected from insects for a while longer. The main pests now are stink bugs and they can damage bolls that are up to about 25 days old. Late season threshold for stinkbugs during the 6th, 7th, and 8th weeks of bloom is 20%, 30%, and 50% internal boll damage respectively.
When checking young bolls make sure to open them up and look for internal damage. Don’t just rely on external lesions. This year we are seeing a lot of fields, especially in areas that received the most rainfall, with spots on bolls that look like external stinkbug damage. However, these spots are actually caused by bacteria or fungal disease and there is no internal damage in the bolls like we see with stinkbug feeding. If this is the case there’s no need to spray for stinkbugs.
Make sure to cut open young bolls and look for internal damage. Don’t just rely on external lesions. This year we are seeing a lot of fields, especially in areas that received the most rainfall, with spots on bolls that look like external stinkbug damage. These spots, however, are actually caused by bacteria or fungal disease.
Source:ufl.edu