EFFECT OF THE DITHIOCARBAMATE FUNGICIDE MANCOZEB ON SUGARCANE GROWTH AND SOIL BIOLOGY IN YIELD DECLINE AFFECTED SOILS

摘要

The dithiocarbamate fungicide mancozeb is used extensively around the world for control of foliar diseases. Initial yield decline research in the early 1990s investigated soil application of fungicides for the amelioration of poor root health in sugarcane. Experiments in both the glasshouse and field have since shown that root health and plant growth improve dramatically following mancozeb application to soil. Experiments have also shown there is a strong dose-response relationship between mancozeb and plant growth, that soil microbiological populations are related to fungicide dose, and there appears to be evidence linking a decrease in dematiaceous (dark sterile) fungal root colonisation with fungicide application and improved sugarcane growth. The evidence suggests soil fungi contribute to sugarcane yield decline.