The control of breakdown of potato seed pieces with fungicidal dusts
Australian Journal of Experimental Agriculture and Animal Husbandry 20(107): 737-739
The breakdown of potato planting material is a serious problem in southern Queensland [Australia], particularly where cut seedpieces are used. Captan (50 g kg-1) or zineb (40-200 g kg-1) dusts are used to reduce losses. A number of chemicals were compared with a standard zineb (80 g kg-1) treatment and no treatment under field conditions. While zineb significantly reduced breakdown in 4 of 8 experiments, mancozeb at equivalent concentration was significantly better in 3 of 4 experiments. Mancozeb at 400 g kg-1 was significantly better again than the lower concentration. The 400 g kg-1 concentration of mancozeb was evaluated on 3 seed consignments for effect on plant stand and yield. The number of plants that emerged was increased by 29%, with a 34% increase in yield. The increase in yield over what could be expected from improved numbers of plants is attributed to the control of wilt diseases and prevention of early crop senescence, which followed the prevention of basal stem rot by retention of seedpieces.