Department of Entomology, Orissa University of Agriculture and Technology, Bhubaneswar-751 003, Orissa (India).
*Present address: All-India Coordinated Rice Improvement Project, Regional Research Station, Chiplima, Sambalpur-768 025, Orissa (India).
The pest control potentialities of neem seed kernel extract (NSKE) and neem cake extract (NCE) as rice seedling root-dip (SRD) against green leaf hopper (GLH), Nephotettix virescens (Dist.), during 1990 and 1991 summer seasons, were investigation under greenhouse conditions. The treatments indicated marked reduction in survival of the nymphs and adult emergence, prolongation in the duration of nymphal period and low growth indices. Among neem products, NCE 10% + 1% urea was most effective resulting in lowest adult emergence (13.34%) and growth index (0.76) followed by NSKE 5% + 1% urea which resulted in 20.0% adult emergence with 1.14 growth index as against 85% and 5.49 in untreated control, respectively. However, chlorpyriphos SRD treatment at 0.02% was superior to neem products against GLH, the corresponding figures being 5.0% and 0.28. The adverse effect of neem products on GLH was more pronounced at higher concentration than at lower concentration. At NSKE 2.5% + 1% urea and NCE 5% + 1% urea, the nymphs becoming adults and the growth indices were 43.33 and 28.34 per cent, and 2.55 and 1.62, respectively.
