Comparative field efficacy of chemical, botanical and biological agents against foliar nematode, Aphelenchoides besseyi infecting tuberose.

摘要

A field experiment was conducted at Central Research Farm of Bidhan Chandra Krishi Viswavidyalaya, Nadia, India with the treatments comprising of monocrotophos 36SL at 500 ppm (T₁), carbosulfan 25EC at 750 ppm (T₂), cartap hydrochloride 50WP at 750 ppm (T₃), NSKE 10,000 ppm (T₄), Pseudomonas fluorescens at 2 g/litre of water (T₅), farmer's practice (T₆) and untreated control (T₇) to test the efficacy of chemical, botanical and biological formulations for managing foliar nematode problem in tuberose. Observation taken from November, 2004 to August, 2005 showed that incorporation of different formulations significantly reduced nematode attack as compared to untreated plots. The application of monocrotophos 36SL at 700 ppm as bulb treatment for 6 h followed by four foliar sprays at 15 days interval significantly reduced nematode disease in tuberose. The nematode infestation ranged from 29% to 55% in the untreated plot whereas in all the treated plots the infestation level was relatively low (14% to 37%) and the lowest (14% to 29%) infestation was observed in T₁. The average number of flower stalk was the highest in T₁ which was followed by T₂, T₃, T₄ and T₅. The PDI value varied from 13 to 36 in the treated plot, 26 to 48 in farmers' practice and 29 to 53 in the untreated plots. The nematode population per flower stalk was found maximum (mean population density 3403/flower stalk) in the untreated plots as compared to treated plots. Considering overall performance of the treatments, T₁ was found to be the best treatment which was followed by T₂, T₃, T₄ and T₅. In terms of cost-benefit ratio, T₁ ranked first followed by T₅, T₄, T₂, T₃ and T₆.