Evaluation of mineral oils and plant-derived spray adjuvants, mancozeb formulations and rates of application, for the control of yellow Sigatoka leaf spot (caused by Mycosphaerella musicola) of bananas in far northern Queensland, Australia

Five mineral oils, four plant oils, and a plant-derived non-ionic sticker/adjuvant were evaluated for the control of yellow Sigatoka of banana in a field experiment in far northern Queensland, Australia. Treatments were compared with the industry standards BP Miscible Banana Misting Oil and Fuchs Spray Oil used at the recommended rate of 4075 g a.i./ha. The plant-derived products were less effective (P < 0.05) at controlling yellow Sigatoka than either industry standard mineral oil. All the mineral oil treatments gave more effective disease control (P < 0.05) than any of the plant-derived treatments. Increasing rates of application of BP Miscible Banana Misting Oil (2853, 4075, 6520 or 8150 g a.i./ha) resulted in an increase in the control of yellow Sigatoka. In a second field experiment, 13 treatments consisting of four formulations of mancozeb used at varying rates of application were evaluated. There was no significant difference (P > 0.05) between mancozeb formulations. Disease assessments conducted 2 weeks prior to harvest showed that mancozeb as Dithane DF at 1000 g a.i./ha was less effective than Dithane DF at 1760, 2000 or 2500 g a.i./ha in controlling yellow Sigatoka.