Combination of resistant rootstock and non-fumigant nematicide for the management of Meloidogyne floridensis on tomato

Summary Meloidogyne floridensis is one of the emerging species of root-knot nematodes in vegetable production in the Southern USA. It can reproduce on commercial vegetable cultivars that have resistance to the common tropical root-knot nematode species ( i.e. , M. incognita , M. arenaria and M. javanica ). The objective of this study was to evaluate the Solanum sisymbriifolium line Sis Syn II as rootstock, in combination with drench application of a non-fumigant nematicide, fluazaindolizine, for managing M. floridensis on tomato. This study was conducted in artificially infested microplots under field conditions at two different locations in Georgia, USA in 2021. Treatments were arranged in a randomised complete block design with eight replications at one location and four replications at the other. The tomato cultivar ‘Roadster’ was used as the scion. Control treatments included non-grafted, and ‘Roadster’ grafted onto ‘Roadster’ rootstock (self-grafted). Our results showed that, in both experiments, Sis Syn II (reproduction factor: 0.07) significantly reduced the population of M. floridensis compared to the non-grafted (4.37) and self-grafted (6.86) controls. Similarly, the galling index was lower for Sis Syn II (0.61) compared to the non-grafted (4.13) and self-grafted (3.90) controls. Moreover, grafting onto Sis Syn II increased the average biomass and yield of the tomato in both experiments. However, fluazaindolizine drenching did not exhibit any effect on M. floridensis populations or the yield increment of tomato. Our study demonstrates that Sis Syn II is effective in management of M. floridensis . Grafting the desirable tomato cultivar onto this rootstock can significantly suppress M. floridensis population and increase crop yield.