Student/presenter: Lee Fischel, B.S. student, Department of Plant and Soil Science, Texas Tech University
Format: Poster presentation
Title: Growth and Yield of Greenhouse Grown Lettuce in Response to Secondary Metabolite in Organic Soilless Production System
Fischel Lee, Azeezahmed Shaik, Sukhbir Singh, Thayne Montague, and Vikram Baliga
Department of Plant and Soil Science, Texas Tech University
Compared to conventional systems, organic production systems are generally associated with a 20-50% reduction in yield. Within organic soilless production systems, the availability of nutrients from organic fertilizers is highly limited. This is due to a lower mineralization rate with less nitrogen supply, which leads to lower productivity. Therefore, a greenhouse study was conducted to test the combined effect of secondary metabolites (SM) and liquid organic fertilizer (LOF) to improve growth and yield of lettuce under a soilless production system. During the spring season of 2022, butterhead lettuce cultivar ‘Rex' and iceberg lettuce cultivar ‘Crispino' were evaluated with or without the application of SM, fertilized with LOF, and compared to an inorganic fertilizer (IF) control. SM was diluted with water to a ratio of 1:500 and applied to plants at ten-day intervals. Respective fertilizer treatments were applied at 2 dS.m-1 every five days. The experimental design consisted of a split-split-plot design with eight replications. Compared to Rex, results indicate Crispino had greater fresh biomass (17%), and total leaf area (39%) for each plant. For SM, differences in growth parameters were not found between cultivars. Among fertilizer treatments, the use of LOF resulted in reduced fresh biomass and plant leaf area compared to plants fertilized with IF. This study demonstrates lettuce response to SM is to be inversely related to the growth and yield of lettuce. However, the use of LOF resulted in improved performance of lettuce in the organic soilless production system.