Effects of Melia azedarach on Meloidogyne incognita in vitro and in vivo conditions

Abstract

Different concentrations of aqueous extracts (0%, 1%, 2% and 4%) of dried leaves, seed, seed kernels and seed coats of Melia azedarach L. were tested for their effect on motility and mortality of second stage juveniles (J2s) of Meloidogyne incognita in vitro. Also, in glasshouse conditions, the effects of powder preparations (0.0, 0.02, 0.04 and 0.08 w/w) of the same plant materials were examined on nematode activity and plant growth components of tomato (Solanum lycopersicum L.). The extracts of all plant parts and at every concentration immobilized 100% of J2s. Maximum (100%) J2 mortalities were given by concentrations of 2% and 4% of seed kernel and 4% of whole seed. No J2 mortality was observed at 1% water extract concentration of leaves. In the glasshouse, all treatments significantly reduced numbers of galls, egg masses and eggs in tomato roots, J2s in soil and tomato roots and final nematode population. Rates of 0.04 and 0.08 w/w of the seed kernel and of 0.08 w/w of the seed coat powders completely controlled the nematode in tomato roots. All treatments significantly (P<0.01) reduced tomato root length and shoot length in comparison to the non-infested and non-treated control.