Effects of Acacia albida and Crotalaria retusa on the Growth and Development of Tomato

Abstract

Tomato fruits play an important role in human nutrition because of their high content in health-promoting substances. However, the cultivation of the crop requires substantial chemical (fertilizers and pesticides), which can impair the nutritional value of fruits produced and harm the environment. This study aimed at using biological material to improve the tomato cultivation system. Tomato seedlings were transplanted in perforated polythene bags containing a soil enriched with powder or extraction residues from leaves of Acacia albida and Crotalaria retusa. Aqueous, ethyl acetate, chloroform or hexane extracts from leaves of Acacia albida and Crotalaria retusa were sprayed on aerial parts of tomato plants. Of a total of twelve parameters measured, eight parameters were significantly improved after treatments with aqueous or chloroform extracts from A. albida leaves, six after soil enrichment with the powder of A. albida leaves, four after foliar sprays of ethyl acetate extract from C. retusa leaves, three after soil amendment with powder or extraction residues from leaves of C. retusa or extraction residues from A. albida leaves, two after the application as sprays of hexane extract from A. albida leaves, and one after treatments with hexane extract or powder from leaves of C. retusa. However, foliar sprays of the aqueous extract from leaves of A. albida had the most efficacious effects, leading to increases in the number of fruits per raceme, number of fruits per plant, number of racemes per plant, root biomass, shoot biomass, fruit biomass and total biomass, respectively, by 2.3 (38.98%), 35.1 (92.61%), 2.5 (39.06%), 6.1 g (50%), 74 g (29.75%), 300 g (42.85%) and 300 g (30%). These treatments also induced a decrease in the rate of flower abortion in tomato plants by 6.3 (25.09%). Foliar sprays of aqueous extracts from leaves of A. albida could be integrated into the tomato agricultural practice in order to reduce the quantity of chemical inputs usually required.