EFFECT OF SALICYLIC  AND  JASMONIC  ACIDS  ON  THE  RESPONSE OF TOMATO PLANTS TO ROOT KNOT NEMATODE MELOIDOGYNE INCOGNITA, INFECTION

[72]

Mahgoob¹, A.E.A.  and  Sanaa, A.M. Zaghlool²

ABSTRACT

In a green-house experiment, 45 day old tomato seedling (Lycopersicon esculentum Mill. Cv. Super strain-B) received nematode, Meloidogyne incognita, inoculum (500 juveniles/pot) and plant growth regulators (PGR_S); salicylic acid (SA) at 20 & 40 ppm and jasmonic acid (JA) at 5 & 10 ppm. PGR_S were applied as foliar spray and soil drench  in separate treatments and in different times; two days before, two days after  and two days before + after nematode inoculum. Double applications of SA at 40 ppm as soil drench and JA at 5 ppm as foliar spray as well as JA at 10 ppm (after inoculum soil drench)  induced resistance to nematode as indicated by the reduction in the number of females with and without egg masses and number of galls. Most of JA at 10 ppm treatments reduced number of females without egg masses and number of galls. These effects were associated with high production of phenols particularly in roots. Foliar spray applications of SA at 20 ppm after inoculum and SA at 40 ppm before + after inoculum increased  females without egg masses and galls number. In the same time, both applications stimulated plant growth as shown by the increase in plant fresh and dry weight, leaves number and soluble proteins concentration which were obtained by SA at20 ppm as well as the increase in shoot fresh & dry weight, fruit weight and chlorophyll concentrations which were obtained by SA at 40 ppm. These treatments were suggested to exhibit tolerant effect in tomato plants.