Response of Ocimum basilicum to moringa leaves extract, moringa seed cake and/or vermicompost

Abstract

Ocimum basilicum is one of the main economic medicinal plants crops and it is a culinary herb. Its essential oil has several biological and pharmacological impacts. Plant-derived bio-stimulants such as moringa leaves extract, moringa seed cake and vermicompost are known for improving the physiological processes in plants and so far increasing the growth and yield of plants. This study was conducted to evaluate the impact of foliar application of moringa leaves extract (0, 0.3 and 0.6 %) and soil application of moringa seed cake and/or vermicompost (100% moringa seed cake, 75% moringa seed cake + 25% vermicompost, 50% moringa seed cake + 50% vermicompost and 100 % vermicompost) on basil plants among two cuts during 2020 and 2021 seasons. Application of 75% moringa seed cake + 25% vermicompost + 0.3% moringa leaves extract resulted in the highest values of plant height, fresh and dry weight (g) and yield (ton ha-1). While, the interaction between 100% moringa seed cake fertilization and 0.3% of moringa leaves foliar-spray gave the maximum phenolic content and antioxidant activity in both cuts. On the other hand, application of 50% moringa seed cake with 50% vermicompost and 0.3% moringa leaves extract gave the maximum values of oil percentage and yield (ml plant-1 and L ha-1) in both cuts of both seasons, with no significant differences between this treatment and 75% moringa seed cake + 25 % vermicompost + 0.3% moringa leaves extract. Additionally, the GC/MS analysis of oil showed trans-cinnamic acid, methyl ester as the main constituents of the essential oil, followed by L-camphor, cis-cinnamic acid, methyl ester then eucalyptol and β-linalool in both cuts. Application of 100% moringa seed cake without spraying moringa extract (0%) increased the biosynthesis of trans-cinnamic acid, methyl ester (54.93 and 60.33% for the first and second cuts, respectively). It could be concluded that, the application of 75% moringa seed cake + 25%
vermicompost + 0.3% moringa leaves extract is the recommended treatment for growth and production as well as oil yield and quality of O. basilicum plants.