Root-Knot Nematode (Meloidogyne javanica) – Deficit Irrigation Interactions on Eggplant Cropped under Open Field Conditions

To investigate the influence of deficit irrigation on the root-knot nematode, Meloidogyne javanica, and its interaction with the eggplant crop, field experiments were conducted at two drip-irrigated agricultural areas in Jordan. Effects of limiting irrigation levels to 80, 60, 40 and 20% of the field capacity (FC) were compared with full irrigation (100%) treatment. Growth of eggplant plants was greatly reduced at irrigation levels of 40 and 20% FC at one field location, suggesting that the influence of deficit irrigation is field-dependant. Fruit yield was similar at all irrigation levels, except at 20% level, where a lower yield was noticed compared to 100% irrigation. Root galling of eggplant caused by the nematode was significantly lower at irrigation levels of 20 and 40% than 80 and 100% of FC, but was field-dependant at 60% of FC. The final nematode population was obviously lower at irrigation levels of 20, 40 and 60% than 80 and 100%. Thus, deficit irrigation to levels of 40 or 60% of FC can be utilised for the management of M. javanica infection in eggplant under field conditions.