Dalapon, amitrole, and weed oil compared for effectiveness in control of bermudagrass in California citrus orchards

Dalapon, amitrole, and weed oil, used alone, as mixtures, or in combination, were compared for effectiveness in the control of bermudagrass. Split applications of dalapon, properly timed, were more effective than single applications with the same total amount of herbicide. Amitrole, and to a lesser extent dalapon, was more effective when applied late in the growing season. Variation in spray volume, the presence or absence of surfactant, or the inclusion of small amounts of kerosene had no effect on the toxicity of amitrole. Mixtures of dalapon and amitrole were less toxic than was dalapon applied alone at the same rate. Split applications of amitrole were less effective than single applications containing the same total amount of herbicide.