Comparative suppressive effect of some organic acids against Meloidogyne incognita infecting tomato

Abstract

The comparative suppressive potential of some organic acids known as resistance inducing chemicals viz., salicylic acid (SA) and its two derivatives; acetylsalicylic acid (ASA) and 3,5-dinitrosalicylic acid (DNSA), along with Lascorbic acid (AA), oxalic acid (OA) and citric acid (CA) for managing Meloidogyne incognita infecting tomato plants was investigated under greenhouse conditions. The results showed that all tested organic acids as well as the application methods significantly reduced tomato root galls and 2 nd stage juvenile numbers in soil compared with control. Except DNSA and AA, foliar application of tested organic acids was more effective in reducing nematode galls than soil drench application. Foliar application of ASA caused superior effect in the reduction of J2 in soil (100 %) followed by AA (89.44 %), OA (88.25 %) and SA (70.69 %). CA (96.52 %) was tended to be the most effective chemicals in reducing J2 in soil when applied as soil drench. All treatments enhanced shoot and root length of tomato as well as shoot weight compared with the untreated check. Only SA and DNSA significantly increased the root weights. DNSA enhanced the growth indices of tomato plant when used as foliar spray more than soil drenching and opposite trend was observed for OA. These chemical activators have potential to suppress M. incognita infection through the stimulation of tomato tolerance.