Influence of foliar Moringa oleifera leaf extract (MLE) application on growth, fruit yield and nutritional quality of cherry tomato

Tomato (Solanum lycopersicum) is the most commonly produced and most-widely consumed horticultural commodity in South Africa and, indeed, worldwide. The demand for high-quality tomato fruit is increasing significantly due to the health benefits associated with its consumption. Consequently, application of moringa leaf extract (MLE), a method that has been shown to increase yields and/or quality of agricultural food crops, could also be used in tomato production. A pot experiment was, therefore, conducted to determine the effect of foliar MLE application on improving plant growth parameters, yield and quality of tomatoes. Red cherry tomatoes, grown from seed, were transplanted and grown in a glasshouse with a fan-cooling system and heat pumps. Twenty-five tomato plants, five plants per replicate received various foliar application of MLE starting two weeks after transplanting. This treatment was repeated weekly until first fruit set. Applications included: four controls, methanol (20, 50 and 80%) (ME) as well as control (water, M0), MLE (20, 50 and 80% (v:v; extract: water) of a 95% methanolic extract. Observations on plant growth and development and fruit sampling were carried out weekly. Foliar application of 20 and 50% MLE gave the best growth and tomato yield. Total soluble solids were not significantly influenced by MLE; however, foliar application of 20% MLE had a tendency to positively influence carotenoids and colour (a*) of cherry tomato. Although further studies on the most suitable concentration of MLE are required, the potential of MLE as a biostimulant to improve quality and yield of cherry tomatoes has been demonstrated.