Tomato grafting as alternative methods for control of soil-borne diseases of greenhouse tomato

Several soil-borne diseases including root knot nematode, Fusarium and Verticillium wilts affect tomato production in Iran where no satisfactory out-comes achieved in chemical applications. In the present study, the efficacy of grafting was assessed in the control of these diseases through grafting of a susceptible cultivar (Niagara) on root stokes (tomato NKVF or eggplant cv Jahromi). The terminal leaves of Niagara seedlings were cut and grafted as scion on NKVF and eggplants rootstocks. Grafted plants were kept under plastic bags to maintain humidity up to 10 days. The grafted plants were then inoculated with Meloidogyne javanica, Fusarium oxysporum and Verticillium dahlia before transplanting in pots containing sterilized soil. The experiment was carried out in a completely randomized design with 4 replications. The efficacy of grafting was evaluated in the control of associated diseases through determination of disease severity index, number of galls, final population and reproduction factor of the nematode as well as measurement the plant growth parameters. Analysis of variance was conducted using SAS software and the means were compared using Duncan's multiple range test at 5% probability level. Grafted plants treated with M. javanica showed that grafting led to better plant shoot growth, hence better yield, but did not any negative impact on nematode population. Disease severity caused by F. oxysporum was calculated 80, 35 and 23.33% where the root weight of plants were measured as 7.28, 12.29 and 15.81 grams in non-grafted Niagara cultivar, and grafted ones on NKVF and eggplant respectively. Disease severity due to V. dahliae was measured as 80, 35 and 23.33 in Niagara cultivar and the grafted Niagara on NKVF and eggplant respectively while, the mean weight of roots were measured 7.28, 12,29 and 15.81grams accordingly. This study showed that grafted Niagara plants on either NKVF or eggplant can control Fusarium wilt in tomatoes. However, the grafting impact on plant growth and production parameters as well as facilitating of grafting techniques needs further research.