Seed treatment with a binary pesticide and aqueous extract of Eclipta alba (L.) Hassk. for improving sorghum yield in Burkina Faso.
Seed health testing and field trials were carried out in Burkina Faso to evaluate the effects of seed treatment with aqueous extracts of Eclipta alba and a binary pesticide Calthio C 50 WS (thiram 25%, chlorpyrifos ethyl 25%) on seedborne fungi, seedling emergence, and yield of sorghum. The treatments included soaking seeds with E. alba extract (6.25 to 25% concentrations), soaking seeds in water, dusting seeds with pesticide (4 g kg–1 of seeds), and no treatment. Seed samples with moderate to high infection levels of Curvularia Boedijn., Fusarium Link: Fr., and Phoma Sacc. were used for testing. E. alba extract and Calthio C caused significant inhibition of Leptosphaeria sacchari Breda de Haan (syn. Phoma sorghina Sacc.) in vitro. In field trials, a stimulatory effect on seedling emergence and yield increases of 7 to 38% were observed for E. alba and the pesticide treatments, as compared to no treatment. Yield increases were significant for plant extract and pesticide in two out of three trials. No consistent effect on yield was observed for water treatment. Our findings represent the first large-scale field testing of E. alba for seed treatment of sorghum and the first direct comparison with a thiram-based pesticide and seed priming.