SUPPRESSIVE EFFECT OF SOME AMiNO ACIDS AGAINST Meloidogyne incognita ON SOYBEANS

The amino acids; L-alanine, OL-aspartic, L-cysteine, Leglutamic, L
hydroxyproline, L-phenylalanine and L-proline were evaluated for their efficacy
against the root-knot nematode, Meloidogyne incognita , and in improving growth of
the infected soybean plants. Foliar spray applications of three concentrations of the
tested amino acids revealed their potent effects on the nematode development and
reproduction. However, variability in such effect was, obviously, noticed linking with
properties of the amino acids and the used concentrations. Conclusively, the
nematode final population and its rate of build up were decreased in most amino acid
treatments in comparison to those of the check. Also, significant improvement in
growth parameters of the infected soybean plants were obtained by most amino acids
applications. However, no or little adverse effect on growth parameters was noticed.
Hence, it is suggested that amino acids specially L-alanine , L-cysteine, L-glutamic
and L-hydroxyproline at their suitable concentrations may affect directly and/or
indirectly the invaded nematodes by inducing a variety of resistance to the host.