Cost-benefit of fungicidal control of anthracnose on sorghum in northern Nigeria

Field studies were conducted to evaluate the economics of controlling sorghum anthracnose caused by Colletotrichum sublineolum using different fungicides. The field experiments were laid out at the Research farm of the University of Maiduguri (Latitude 11 15 N & Long. 13 15 E) during the rainy seasons of 1998 and 1999. Six fungicide combinations: metalaxyl followed by benomyl, metalaxyl followed by mancozeb, metalaxyl followed by carbendazim, thiram followed by benomyl, thiram followed by mancozeb, thiram + carbendazim were applied as treatments for the control of the fungus at different stages of the plant growth while the control plots were left un-treated. Application of any of the fungicide treatments resulted in 70 80% reduction of anthracnose and more vigorous plants that gave higher yields, as much as two times that of un-treated control. The cost-benefit analysis revealed the positive return per hectare from the use of the fungicides for the control of anthracnose in the region. Using seed treatment metalaxyl followed by foliar applied benomyl for instance, gave 51% yield increase, which translated into a net profit of N45375.00 of Nigerian naira equivalent to US $454.00 per hectare. Even the least effective fungicide treatment (seed treatment thiram folloed by foliar appliedd benomyl) in this trial gave a yield increase of 34.8% over the control. This translated to a net profit of N32925.00 equivalent to US $329.25 per hectare. These returns are attractive particularly for the relatively high yielding early maturing local sorghum variety Warwarabashi.