INDUCTION OF RESIISTANCE IN TOMATO PLANTS AGAINST ROOT-KNOT NEMATODE BY SOME CHEMICAL AND PLANTS EXTRACTS(a)

Abstract

Different agents were tested as inducing re-sistance factors in tomato plants against root-knot nematode Meloidogyne incognita. These agents include ethyl salicylic acid, (0.125 ml/l) jassmonic acid (0.125 ml/L) sincocin solution, (0.1%) agrispon solution (0.1%) water extract of mango malformed inflorescence (7.5%), coconut milk solution (2%) as root dipping during transplanting and spraying after one month from transplanting. Data obtained clearly indicated that sincocin solu-tion, extract of mango malformed inflorescence, agrispon solution and jassmonic acid led to a great reduction in disease severity, number of galls/ root, number of females/ root and number of egg masses/ root, followed by ethyl salicylic acid and coconut milk descending order. All tested agents did not affect juvenile's viability except mango malformed inflorescence extract and coco-nut milk solution which led to slight effect on juvenile viability. All tested agents increased plant growth in the presence of nematode inocula in comparison to untreated plants. In this respect coconut milk solution had the superior effect. Data indicated that the tested agents induced resistance in treated plant and the mechanisms of their mode of action needs further studies.