Phytostimulatory Effects of Moringa oleifera leaf extract on the growth and chlorophyll composition of Amaranthus hybridus using phytopriming and foliar spraying techniques

Abstract

The consistent dependence of agriculturalist on inorganic fertilizer not only continues to pose an environmental threat, but also remains unsafe for human consumption. In this study, Moringa oleifera leaf extract (MLE) was used as a plant growth stimulator for Amaranthus hybridus, using two different application techniques (priming and foliar spraying). The treatments used for the experiment were 10%, 20%, and 30% MLE solutions, and 10%, 20%, and 30% mg/L gibberellic acid (GA₃) solutions, and distilled water. Viable seeds of A. hybridus were primed with MLE treatments and sown in 21 different polythene bags filled with top soils. Similarly, seeds of A. hybridus were sown in another 21 polythene bags and sprayed foliarly every two days for four weeks. All the 42 bags were arranged in a Completely Randomized Design at the screened house of the Botanical Garden, Lagos State University. The results from the growth analysis showed that although 20% GA₃ had the highest value of 14.37 cm for shoot height (p<0.05), 30% MLE was the closest among the MLE treatments with 9.12 cm. While there was no significant difference across the samples for stem girth and number of leaves (p>0.05), there was a standout performer for chlorophylls. 30% MLE recorded the highest values of 9.33 mg/100g, 4.67 mg/100g, 14.00 mg/100g for Chlorophyll a, b, and total chlorophyll, and all with significant differences. Interestingly, all the best performing treatments were from A. hybridus plants cultivated using the foliar spraying techniques, thereby making it a better application technique than the phytopriming. Generally, the 30% MLE displayed the best potential in the stimulation of growth and enhancement of chlorophyll contents of A. hybridus which could be of great value to those in the agriculture, food and pharmaceutical industries.