Cotton may benefit from insecticide - herbicide interactions, such as the case where disulfoton safens cotton against clomazone injury. In other cases, research has shown cotton phytoxicity due to detrimental interactions between applications of insecticides and herbicides. Previous research has shown significant visual injury from tank mixtures of malathion and pyrithiobac applied at a delivery volume of 20 gallons per acre (GPA); however, yield and fruiting patterns were generally unaffected. Laboratory research has shown increased injury when pyrithiobac and malathion were applied under cool conditions. In these experiments malathion and pyrithiobac were applied at 1.16 and 0.0625 lbs ai/A, respectively. The increased use of pyrithiobac along with the use of malathion in the boll weevil eradication program has heightened concern over potential interactions. Additionally, questions have arisen regarding the potential for interaction when malathion is applied as an ultra low volume (ULV) application undiluted at 0.125 GPA.