Impact of growth promoters on te storage life of moringa leaf extract as biostimulant in wheat

Abstract

Moringa leaf extract (MLE) is a natural crop growth enhancer being rich in minerals, antioxidants and phytohormones. However, type of moringa and effective storage life of extract was not known. The research was planned to compare the effectiveness of MLE from different landraces of Moringa oleifera present in Pakistan and to optimize its storage life. During first experiment, leaf extracts were taken from three landraces i.e. white seeded moringa (WSM), black seeded moringa (BSM) and PKM1 (Indian variety) and were applied as priming agents and foliar application alone or in combination with hydrogen peroxide, ascorbic acid and salicylic acid on wheat. All the priming strategies significantly invigorated the wheat. Priming was more effective by moringa alone than blending with other compounds. Among the type of moringa as a source of extract, WSM was more effective in reducing the time to start emergence, E50 and increasing the seedling vigor. On the basis of the results, WSM was selected for further experimentations. During second experiment, both priming and foliar application of leaf extract of white seeded moringa alone and in combination with growth promoting substances improved the yield parameters while maximum performance of wheat crop was observed where alone MLE was applied as a foliar spray as compare to control. During third experiment, MLE alone and in combination with growth promoting substance and preservative was stored at low and ambient temperature. Chemical analysis of stored MLE showed that total phenolics and ascorbic acid concentrations were decreased with increase in storage time. Fresh MLE performed better than stored MLE regarding germination and seedling fresh and dry weight as well root shoot length. During the last experiment, fresh and stored MLE was applied as foliar spray to observe the crop growth enhancing potential of stored MLE. All MLE treatments improved both biochemical and yield parameters of wheat as compare to control which received no exogenous application of MLE. The growth enhancing capabilities significantly decreased with storage time under both sowing conditions. Worth seeing observation was, increase in biological and economic yield in late sown crop plants due to foliar application of fresh MLE as compare to control in timely sown wheat. Maximum biostimulant potential of leaf extract of white seeded moringa, alone and in combination with growth promoting substances, was observed regarding seedling performance which were correlated with higher contents of ascorbic acid and phenolics.