The influence of NaCl on the infectivity and reproduction of the root-knot and
the reniform nematodes was studies using four concentrations (500, 1000, 2000
and 3000 ppm) of sodium chloride (NaCl) in the irrigation water of eggplant, squash
and cowpea. Increasing salt concentration and consequently soil Ec resulted in
significant increase in number of M. incognita galls and egg-masses/ eggplant roots
as compared with the check plants (0 salt). The highest number of galls was
observed at 3000 ppm NaCl. Increasing NaCl concentration in irrigation water
increased females fecundity on the roots of eggplant and squash. However opposite
results were observed on cowpea roots. The reniform nematode behaved
differently, whereas the nematode counts increased with increasing salt
concentration on cowpea and decreased on eggplant and squash.
The present results indicated that higher salt concentration adversely affected
the growth of treated plants and significantly increased the damage caused by
nematodes. The influence of salt stress on the nematode development and
reproduction depend on nematode species, salt concentration (soil EC) as well as
the host plant. In general damage in plants under salt stress and infected with the
reniform nematode was more pronounced than those infected with the root-knot
nematode.