Effect of Alkaloids Extracted from Local Lupine Plant on Growth and Yield in Pepper

Abstract

One of the most important modern strategies to increase agricultural productivity is the recycling of wastes rich in important components that stimulate different physiological and biological activities in plants. Alkaloids removed from bitter lupine (Lupinus termis L.) seeds may be a good alternative natural source of industrial chemicals and may encourage plant growth and productivity as the recent global trend "aims to use natural materials to preserve the environment and avoid side effects. Due to the increased demand of sweet pepper (Capsicum annuum L.) for its nutritional content and high acceptance, the study goal is to improve the growth and productivity of the locally produced pepper crop by using active biological substances such as alkaloids (free of carbohydrates) extracted from bitter lupine. Bitter lupine seeds were used to extract the alkaloids free of sugar, which were subsequently dried at a temperature no higher than 50 °C. Alkaloids extract was added to each plant at concentrations (0, 500, 100, 1000, 2000) mg dw/200 ml water and its effect on vegetative evolution, output, and quality of fruit cultivar Rumi Suez were evaluated. The experiment was conducted under greenhouses in the Agricultural Research Center/Ismailia Station during the winter agricultural seasons 2019/2020 in sandy soil using three replications, Randomized Complete Block Design (R.C.B.D) and the differences among the means were tested according to Duncan's test at p≤0.05. The results showed a considerable increment in the vegetative development indicators, including plant height, main branches number, leaf area, leaves number, wet and dried weight of leaves and stems and leaves chlorophyll levels, in addition to productivity yield per plant, total yield, vitamin C, and phenols when treated with alkaloids extracted. It was found that the mean number of fruits, yield per plant, total yield, vitamin C content, phenols, and fruit quality increased with increasing concentrations of alkaloids used. In order to achieve the highest production and quality of pepper fruits, it is recommended to add alkaloids extracted from bitter lupine seeds, free of sugars, at a concentration of 2000 mg for each plant, dissolved in an appropriate amount of water around the plant once after two weeks of planting and then repeating it a month after planting.