Eggplant (Solanum melongena L.) Yield Comparisons of Managed Buffelgrass (Pennisetum ciliare L.) Living Mulch Systems to a Conventional Monoculture Bare Ground System in Hawaii

Abstract

Two long-term field experiments were conducted from 1998 to 2000 to compare the yields of marketable eggplant in a buffelgrass living mulch system to a conventional monoculture bare ground system. The initial experiment compared the yields in the conventional treatment to living mulch treatments, that were chemically suppressed at three levels of sethoxydim applied at 0.1, 0.2, and 0.3 kg·ha-1 a.i. Regression analysis did not reveal a significant linear response of eggplant yield to increasing levels of sethoxydim. The average cumulative yield of the three living mulch treatments, 130 days after transplant (DAT), was 4,296 kg·ha-1 compared to 2,079 kg·ha-1 for the conventional treatment. The higher yield in the living mulch treatments was due to a mite infestation that was much more pronounced in conventional plots. In the follow-up experiment, three different living mulch management (mechanical suppression, chemical suppression, and untreated) treatments were compared to a conventional monoculture bare ground treatment. There was no mite infestation affecting this experiment and cumulative yields of marketable fruit at 159 DAT were 5,362, 4,521, 4,155, and 2,535 kg·ha-1 for conventional bare ground, mechanical suppression, chemical suppression and untreated living mulch treatments, respectively. Orthogonal comparisons showed that the yields from the conventional treatments were not significantly different from the suppressed living mulch treatments. However, the eggplant yields from the unmanaged living mulch treatments were significantly reduced in comparison to the conventional and also the suppressed living mulch treatments.