EFFECT OF VERMICOMPOST-TEA AND PLANT EXTRACTS ON GROWTH, PHYSIOLOGICAL, AND BIOCHEMICAL TRAITS OF LETTUCE (LACTUCA SATIVA L.)

Abstract

The vermicompost and exogenous plant extracts as a foliar application can provide as an alternative means to enhance the growth and yield of leafy vegetable crops under low-fertility soil conditions. The objectives of the recent study sought to characterize the effect of vermicompost tea in combining some natural plant extracts to enhance the growth and yield of the lettuce plant. A study on lettuce (Lactuca sativa L.) took place during two successive seasons, in 2018–2019 and 2019–2020, using foliar spray— vermicompost-tea rates in combination with rosemary leaf extract (RLE) and eucalyptus buds extract (EBE). It sought to determine the effects on growth, yield, and some physiological and biochemical traits of lettuce (cv. ‘Dark Green’) grown on sandy soil with drip irrigation. The experiment employed the split-plot design, with four rates of vermicompost tea (0%, 5%, 10%, and 20%) as main plots and three plant extract levels (without, RLE, and EBE) as subplots. The vermicompost tea and plant extracts increased the growth characteristics, photochemical activity, photosynthetic pigments, relative water content, membrane stability index, excised leaf water retention, vitamins C and E, and total soluble solids in lettuce plants compared with the untreated control plots. The interaction and combined application of vermicompost tea (20%) and RLE proved most effective in enhancing the growth and yield traits and physio-biochemical properties in lettuce. Therefore, the integrative application of vermicompost tea (20%) with RLE comes highly recommended for growing lettuce in sandy soil conditions.