Production of tomato (Lycopersicon esculentum) during the hot-wet season in the lowland humid tropics can be increased using grafted plants and rainshelter. This technology can reduce soil-borne diseases, improve the ability of tomato plants to tolerate high temperatures and flooding due to high rainfall, and protect the crop from the impact of heavy rains. AVRDC has developed tomato lines that are resistant to virus diseases and high temperatures. This experiment was conducted to evaluate the performance of these lines in the hot-wet season, with and without rainshelter protection. Tomato lines (CHT501, TLCV15, and FMTT847) were grafted onto eggplant (Solanum melongena cv. EG203) rootstock and grown under rainshelter and open field. Nongrafted plants of three lines were also grown under two rainshelter treatments. The experimental design was a split-plot with four replications. Plants were managed using AVRDC standard practices for summer tomato production. TLCV15 and FMTT847 were highly resistant to tomato leaf curl virus (ToLCV), whereas CHT501 was greatly infected by the virus disease. All nongrafted plants died from bacterial wilt, whereas grafted plants survived the disease and outyielded nongrafted plants by 233% in the open field and 143% under rainshelters. Plants under rainshelters had a slightly lower yield than in the open field, but the difference was nonsignificant. Due to lack of frequent high rainfall during the season, the benefit of rainshelter was not detected and realized. It was concluded that TLCV15 and FMTT847 are well suited for grafted tomato production during the hot-wet season.
Manuel Palada and Deng Lin Wu
Manuel Palada and Deng Lin Wu
Chili pepper (Capsicumannuum cv. Delicacy) was grown in single- and double-bed rainshelters and irrigated using furrow and drip irrigation to determine effect on yield and efficiency of water and nutrient application in the lowland tropics of southern Taiwan during the hot wet season. The experiment was laid out using a split-plot design with four replications. The main plots were rainshelters (single, double, open field) and the two irrigation methods (furrow and drip) were the subplots. Grafted chili seedlings were transplanted in double rows on raised beds at row spacing of 80 cm and plant spacing of 50 cm. The furrow-irrigated crop was applied with basal N-P2O5-K2O at the rate of 180–180–180 kg·ha-1 and 240–150–180 kg·ha-1 of N-P2O5-K2O as sidedressing. The drip-irrigated crop received half of the total rate applied for the furrow-irrigated crop. Significant differences (P < 0.05) in marketable yield were observed between rainshelter treatments. Highest yield (42.2 t·ha-1) was produced from the single-bed rainshelter, and crops grown under double-bed rainshelters produced the lowest marketable yield. Irrigation method did not significantly influence marketable yield, but crops grown under drip irrigation produced a higher yield than furrow-irrigated crops. Nutrient uptake by plants grown under drip irrigation was also higher (P < 0.05) than for furrow-irrigated crops. Water use efficiency was 60.7% higher in drip-irrigated plots. Results indicate that in high rainfall vegetable production areas, drip irrigation minimizes nutrient loss through leaching and maximizes efficiency of fertilizer use.