Sixteen (16) varieties of kenaf of different origin were planted in green house and inoculated with known concentration of RKN. In order to determine the water responses of kenaf (Hibiscus cannabinus L.) to infection with Meloidogyne incognita, Water use efficiency and intrinsic water use efficiency also calculated based on assimilation rate to stomatal conductance and assimilation rate to internal leaf CO2 concentration respectively. Both gas exchange characteristics measuered in this study were affected by M.Incognita race1. Water use efficiency and intrinsic water use efficiency showed the greater value in infected plants than controls. Hence, nematode infection in this study affected gas-exchange properties of kenaf by increasing of water use efficiency and intrinsic water use efficiency compared to control plants.The different genotypes used in the experiment showed different responses of gas exchange to nematode infection. The most affected variety in term of water use efficiency and intrinsic water use efficiency was G 4(Terengganu).The least affected variety in term of water use efficiency and intrinsic water use efficiency was KK60 (M), .Gas exchange measured in both infected and non infected plants however did not have a consistent trend with the time of measurement.
