Moringa oleifera Lamarck: seed quality and potential uses of the leaf extract in organic agriculture

Abstract

Moringa (Moringa oleifera Lam.) is the most spread species of the single gender family Moringaceae. This plant occurs pantropically and gathers in the seeds and leaves, the products of main commercial interest. Considered to be a horticultural tree of high agronomical performance and wide climate and soil aptitude, it has been cultivated all over the Brazilian regions in near and forest spacings and as an agroforestry component. Moringa is recognized as a multi purposes tree by the Food and Agriculture Organization of the United Nations – FAO/UN and the Brazilian Agricultural Research Corporation – EMBRAPA, drawing the attention of farmers, entrepreneurships, researchers, and professionals of agricultural sciences as a strategic crop for the sustainable development, because of its feeding, pharmacological, and energetic potential. The quality of seeds is basal to ensure the ability of a species to ensure its capacity of generating high performance production fields. However, there are no stablished parameters to evaluate the quality of moringa seeds. Regarding the leaf extracts, they have been intensively investigated as a resource for plant nutrition under organic cultivation. Synthetic plant growth promoters are widely used in conventional farming in addition to chemical fertilizers to improve performance. As leaves are source of minerals, vitamins, protein, amino acids, glucosynolates, having a range of bioactive compounds, moringa leaf extracts have been used to enhance production, sanity, and the quality of several crops. Being able to act as an alternative resource for plant nutrition and hormone regulation within organic farming, researcher dedicate to evaluate, among the extraction methods, the ones that promote the best use of moringa leaf extracts in agriculture. The range of applications of such material cover all the stages in plant development. To provide the needed information for seed testing, this work aimed to evaluate samples of moringa seeds submitted to different levels of controlled aging. A biochemical test was made, as the germination test, sprouting test, seed and seedling classification, primary root, and hypocotyl measurements. The enzymes activity of the samples was made after the storage in low temperatures. A study of moringa leaf extracts methods of extraction and potential applications for organic agriculture was carried out. The results indicate that the immersion in 0,5 g/L tetrazolium solution for 2 hours is representative for realizing the biochemical test, and the thermal therapy performs influence over both quality and initial development of moringa seedlings. Regarding the use of the leaf extracts in agriculture, they differ depending on the method of extraction, and can be used in seed primming, as biofertilizer, bios stimulant, bio pesticide, growth promoter, and aflatoxin controller to stored grains.