IMPROVED EMERGENCE OF SOLANUM TORVUM BY SEED TREATMENT

Abstract

Several soilborne diseases severely affect eggplants (Solanum melongena L.) in Japan. Therefore, eggplants are usually grafted on rootstocks of various species resistant to these diseases. For the control of verticillium wilt (Verticillium dahliae Klebahn), Solanum torvum `Torvum vigor' plants are used for rootstocks. However since the seeds started to emerge after 12 - 14 days at 25C and only 40% of them emerged after 30 days, it was difficult to obtain seedlings of uniform size.In this experiment, matric priming treatment of seeds prior to planting was modified to improve the emergence of the seeds of `Torvum vigor'. Vermiculite powder was selected as the substrate to control the water potential of seeds during the treatment. First, samples of 0.25g seeds (235seeds on an average) were mixed with various amounts of vermiculite powder and water at 25C in the dark during 1 week. Thereafter, the treated seeds were planted in soil and incubated at 25C under a 12h daylength regime and the emergence and growth were monitored. Second, the temperature for the treatment, growth regulators added to water, air pressure and components, and the duration of the treatment were varied. Finally, the optimum treatment for improving the emergence of Solanum torvum seeds was developed.