ALTERNATIVE TECHNIQUES FOR THE APPLICATION OF SULFUR DUST TO CASHEW TREES FOR THE CONTROL OF POWDERY MILDEW CAUSED BY THE FUNGUS OIDIUM-ANACARDII IN TANZANIA

Sulphur dusts are widely used in Tanzania to control powdery mildew on cashew trees, caused by the fungus Oidium anacardii. Sulphur distribu tion on mature cashew trees obtained using a motorised backpack duster , a manually powered backpack duster and a locally developed dusting b ag were compared. The most efficient application was from the motorise d duster, although sulphur distribution throughout the canopy of the t ree was uneven with all three methods. The presence of dew when dustin g was demonstrated to increase sulphur deposition. Following applicati on, sulphur deposits on the canopy were found to decline by as much as 80% in 3 weeks.