Drones can’t carry the volume that herbicide applicators cart across fields in massive rigs. But three businesses — Biosorb, Nardo Agribotics and Rantizo — argue they don’t have to. Well-timed applications of as little as 1 ounce per acre can treat the hot spots of a field when delivered by drone, company representatives say.

In terms of current adoption, Rantizo customers include hemp and other high-value crop growers. To grow its customer base, the company plans to build a matrix of recommended practices and drone-sized chemical spray cartridges for problem weeds and pests.