Integrated management of groundnut root rot using seed quality and fungicide seed treatment

Abstract

The effect of seed quality and fungicide seed treatment on root rot of groundnut was studied at Babile, eastern Ethiopia. Seed lots of a commonly grown variety (Oldhale) were divided into two parts. The first part was cleaned (discoloured, shrivelled and broken seeds removed) and treated with the fungicides mancozeb, benomyl or copper hydroxide. The remaining seed lot was planted without cleaning but treated with each of the above fungicides. A split plot design was used, seed quality and fungicides being main and subplot treatments, respectively. Compared with the untreated control, significantly higher seedling emergence and lower plant mortality as well as higher dry pod yield and yield components were recorded from seeds treated with fungicides. Mancozeb-treated seeds had a higher seedling emergence, pod yield, pod number per plant, shelling percentage and seed weight but a lower plant mortality than the other treatments. Cleaned seeds showed lower plant mortality, higher seedling emergence and dry pod yield than uncleaned seeds. The highest pod yield (2344 kg/ha) was obtained from cleaned seeds treated with mancozeb and the lowest (1665 kg/ha) from uncleaned seeds that were not treated with fungicide. Fusarium oxysporum (80%) was the most dominant fungal species isolated from wilting plants observed in the experimental field. Our results indicated that effective management of root rot and significant yield benefit from groundnut can be obtained through integrated use of mancozeb treatment (3 g/kg seed) with properly cleaned seeds.