Biological control of plant-parasitic nematodes in pigeonpea field crops using neem-based products and manurial treatments

The paper presents an account of a field plot experiment to investigate the influence of soil applications of neem-based (Achook and Suneem G) and cro p fertilizer (urea and cattle manure) treatments, separately and in combina tion on free-living, and plant-pathogenic nematode populations and crop pro ductivity. All the treatments significantly decreased the number of plant-p arasitic nematodes with increasing doses. Combinations of both neem-product s with urea were most effective in reducing plant-parasitic nematode popula tions. The neem products and product combinations with urea significantly d ecreased numbers of free-living nematodes compared to controls; however, nu mbers increased in the cattle-manure-treated plots. The growth of pigeonpea (Cajanus cajan L.) was improved in all the treatments, in part due to the control of plant-parasitic nematodes and in part due to manurial effects. U rea was phytotoxic at 330 kg N/ha applied alone: however, it was not phytot oxic at this rate in combination with the neem-based products. (C) 1999 Els evier Science B.V. All rights reserved.