Effect of various exposure periods and concentrations of cured leaf extract of bidi tobacco on egg hatching of root-knot nematodes

Studies on various exposure periods and concentrations of cured leaf extract of Bidi tobacco on egg hatching of root-knot nematodes was carried out in completely randomized design. Result on various exposure periods (1 to 120 hours) and concentrations (1,5, 10 and 15 percent) on egg hatching of root-knot nematodes in cured leaf extract of bidi tobacco cv. GT 5 revealed that with increase in concentrations, there was corresponding reduction in egg hatching. Increase in exposure period upto 48 hours, correspondingly reduced the egg hatching and thereafter, beyond 72 hours to 120 hours, erratic trend was observed. Interactions between exposure periods and concentrations of the extract correspondingly reduced egg hatching upto 48 hours of exposure. Comparison between control and rest of the treatments of extract and durations revealed significant reduction in egg hatching within the extract and on transfer of the egg masses in water, showing ovistatic or ovicidal action of the extract on egg hatching of root knot nematodes.