Influence of changes of soil moisture due to the durations of irrigation on the
development and reproduction of the root-knot (M. incognita) and the reniform (R.
reniformis) nematodes infecting eggplant, squash and cowpea in two different soil
types was studied under greenhouse conditions. Results showed that the highest
counts of the root-knot nematode were recorded on roots of eggplant grown in
loamy sand soil and irrigated at the fourth day. On squash, the highest nematode
counts were recorded on plants grown in sandy loam soil and irrigated every day,
and on cowpea roots grown in the same soil type but irrigated every four days.
Higher reproductivity values of the reniform nematode on eggplant roots were
accomplished in loamy sand soil and irrigated every four days. Significant higher
final population and rate of reproduction on squash and cowpea were recorded on
plants grown in the same soil type but irrigated daily or every other day,
respectively. The influence of the duration of irrigation on nematode development
depend on many factors most of which are the soil type, duration of irrigation,
nematode species as well as the growing crop. The prolonging irrigation period
(decreasing soil moisture) significantly reduced the growth of the infected plants.
Such effect was pronounced with the longest period between irrigation (3 days) in
loamy sand soil.