Effect of low volume copper sprays with polyisobutene sticker on mango blossom blight(Glomerella cingulata)in Dominica

Abstract

Two spraying strategies to control mango blossom blight caused by Glomerella cingulata were tested in Dominica In one trial, a single dose of 4% copper oxychloride (18 g per tree) was applied to foliage before flowering had started, while the other trial compared fortnightly applications of concentrations up to 2%, starting after flowering. The early single dose gave a significant increase in fruit set, whereas the repeated doses gave no significant effects. Early application, followed by a low volume spraying of protectant fungicides, may reduce the cost of disease control. The addition of 0.5% polyisobutene sticker, tested in the single dose trial, gave a consistently improved fruit set compared to the non‐sticker treatment, significant at one recording date; the overall evidence was encouraging. In vitro tests showed that the fungus was less sensitive to copper than to chlorothalonil and some systemic fungicides.