Effect of time of application of sunn hemp aqueous seed extract on root knot nematodes and yield of groundnut

A field experiment was conducted to determine the effects of time of application of sunn hemp (Crotalaria juncea L.) seed extract on root knot nematodes of groundnut. An aqueous sunn hemp seed extract was applied at planting and repeated biweekly till six weeks after planting (6 WAP). Synthetic nematicide (Carbosulphan) application and untreated controls served as positive and negative checks, respectively. The experiment consist of six treatments which were laid in a Randomized Complete Block Design (RCBD). Treatments were replicated three times. Each plot received 500g/500ml of the seed extract at different times of application. The results of the current study revealed that sunn hemp seed extract was most effective against root knot nematodes when applied at planting. The results further revealed that nematode population and root gall index were significantly reduced when the extract was applied at the time of planting (T1). The findings of this study have shown that early application of sunn hemp aqueous seed extract application schedule reduces root-knot nematode severity and improves yield of groundnut under field conditions. Application of sunn hemp aqueous seed extract within the first two weeks after planting would achieve a maximum reduction of root knot nematodes severity and hence improve yields in groundnut under field conditions. This finding will serve as information for future root knot nematodes management interventions. published by the International Journal of Agronomy and Agricultural Research (IJAAR)