Compatibility of Diclosulam with Postemergence Herbicides and Fungicides

Diclosulam is registered for residual and postemergence control of several broadleaf weeds and suppression of annual sedges in peanut in the southeastern United States. Many producers apply herbicides and other pesticides simultaneously to increase the spectrum of pest control or to increase efficiency of operations. However, compatibility of coapplication of pesticides is a concern. Field trials were conducted to evaluate the compatibility of diclosulam with other herbicides and fungicides. Horseweed control by diclosulam in combination with glyphosate, sulfosate, or paraquat was compared to combinations of these herbicides with flumioxazin, tribenuron plus thifensulfuron, or 2,4-D. All treatments that contained diclosulam controlled horseweed at least 86%. Broadleaf signalgrass control by clethodim and sethoxydim was not affected by diclosulam; however, large crabgrass control was reduced when graminicides were coapplied with diclosulam. Common ragweed control was reduced when diclosulam was applied with chlorothalonil and pyraclostrobin but not by azoxystrobin or tebuconazole. Nomenclature: Bentazon; clethodim; diclosulam; flumioxazin; glyphosate; paraquat; sethoxydim; sulfosate; thifensulfuron; tribenuron; broadleaf signalgrass, Bracharia platyphylla (Nash) R. D. Webster BRAPP; common ragweed, Ambrosia artemisiifolia L. AMBEL; horseweed, Conyza canadensis (L.) Cronq. ERICA; large crabgrass, Digitaria sanguinalis (L.) Scop. DIGSA; peanut, Arachis hypogaea L.