By Angela McClure
Desiccant options for grain sorghum are more limited than other crops. Basically we are limited to glyphosate or sodium chlorate. Aim herbicide can be included with another material where morningglory vines are dense enough to interfere with the combine. Gramoxone is not labeled for desiccation of grain sorghum.
For glyphosate products, apply only after seed have reached 30% moisture content or less, and harvest is at least 7 days out. Rates are from 32 ounces to 64 ounces per acre in 10 to 20 gallons of water per acre by ground, or 3 to 10 gallons of water per acre by air. Glyphosate is a slow-acting material and has not been shown to measurably reduce seed moisture in small plot research. It should not be used on sorghum grown for seed production.
For sodium chlorate products, apply 7 to 10 days before harvest at labeled rate. There are a number of products available that have different rates of active ingredient. Consider using the higher recommended rate if applying when weather is cloudy and/or damp.