Yield influence with nutrient, weed and pest management in redgram (Cajanus cajan)

Abstract

Pigeonpea (Cajanus cajan (L.) Millsp.) is the most important food legume, nutritionally an important pulse crop used in various forms but mostly as split pulses or ‘dal’. The grains are rich in proteins, carbohydrate, fat and other nutritional factors and used in daily diet in India. An area of 49,000 ha is under Redgram with a production of 53,000t and productivity of 1043 kg/ha in Tamil Nadu. It is programmed to study the critical component which causes yield reduction in redgram by which we can improve the productivity of the crop. Hence, a field experiment was conducted to study the influence of weed, nutrient and pest management on yield in redgram. The recommended INM (FYM at 5 t /ha /vermicompost 2.5 t/ha + RDF NPKS Zn (25:50:25:20 kg NPKS/ha) + seed treatment with sodium molybdate @4 g/kg seed), IWM ((Pendimethalin at 0.75 kg/ha on 3 DAS + one HW on 40 DAS), IPM (prophylactic spray of Indoxacarb 15.8 % at the time of flowering @ 375 ml/ha + one systemic insecticide spray 15 days after fist spray) and their different combinations were imposed and assessed for their influence on growth and yield in redgram. From this study, it was revealed that there was a yield loss of 46 % without adopting the IWM practices in pigeonpea. Hence weeds are considered to be the most important yield limiting factor in pigeonpea followed by insect infestation especially podfly, pod bug and borers in Coimbatore zone. Adoption of IWM practices has recorded an average weed control efficiency of 63.9% in pigeonpea. Grain yield was significantly higher with adoption of INM+IWM+IPM (994 kg/ha), INM+IWM (978 kg/ha), IWM+IPM (878 kg/ha) and IWM alone (828 kg/ha). Based on economics, it was observed that adoption of IWM alone has recorded higher net income and benefit cost ratio over other treatments. Since the cost of vermicompost is higher, the treatments which include INM and its combinations have recorded lower net income and benefit cost ratio.