Increased feasibility of treating sorghum seeds with Eclipta alba extract by lowering concentration of plant extract and soaking time of seeds

摘要

Previous field experiments in Burkina Faso have demonstrated the efficacy of an aqueous extract of the plant, Eclipta alba in improving crop emergence and yield of sorghum by soaking of seeds for 10-20 hours in 10-25% (w/v) extract. When the effect ofseed treatment was tested in vitro using seedling vigour as the response parameter, results indicated that lowering of the concentration of plant extract (from 10% to2%) and shortening of the soaking time (from 10hto6h) resulted in a similar response asthe higher dose and longer soaking time.In a series of field experiments a yield increase of more than 150 kg/ha was obtained either by applying alow concentration of plant extract (2.5% w/v) or a short soaking time (6h).Thelow dose and reduced soakingtime was further combined in a field trial and resulted in a 180 kg/ha yield increase compared to non-treated seeds. This corresponded to a relative yield increase of 16-27% at field level(p< 0.0042). Also crop emergence was increased significantly (7%>)by treatment with low dose and shortened soaking time (p< 0.005). Experiments in vitro supported the findings and demonstrated a protective activity of the plant extract: the frequency of seedlings with symptoms of seed-borne fungal infection in roots was reduced more than three-fold in plants from treated seeds (p<0.001). Naturally infected seed material was used in all experiments and the findings are therefore directly applicable and relevant for farmers in Burkina Faso, where E. alba is abundant.