CHEMICAL CHARACTERIZATION OF Hyptis suaveolens AND Bridelia ferruginea AND THEIR ASSESSMENT FOR NEMATICIDAL PROPERTIES AGAINST Meloidogyne incognita INFECTING SOYBEAN (Glycine max)

Abstract

Soybean production is constrained by root-knot nematodes (RKNs) that attack the root system leading to reduced productivity in Nigeria. Thus, these field and screenhouse experiments investigated the use of powdered leaf extracts of Hyptis suaveolens and Bridelia ferruginea as plant-based nematicides in the control of RKNs infecting two varieties of soybean.The studies were 2 x 3 factorial experiments fitted into a randomized complete block design,. Each pot in the screenhouse was inoculated with 1000 eggs at planting, whereas the field was naturally infested. Hyptis suaveolens and Bridelia ferruginea were applied at 200 g per stand, twice, at a four-week interval, first at one week after planting. The untreated pots and plots served as the controls for the experiments. Phytochemical screening was conducted on samples of the plant materials to determine the presence of organic compounds. Data collected on growth parameters, pod production, and nematode population were subjected to analysis of variance and means were separated using the Fisher's Least Significance Difference Test at P=0.5. The results revealed that the treated plants recorded significantly higher (P=0.5) growth and yield than the controls. The untreated TGXP1448-2F plants recorded the highest final nematode populations. In spite of the susceptibility of both varieties to M. incognita, powdered form of Hyptis suaveolens had significantly higher performance than that of Bridelia ferruginea, especially on the LOCAL variety. Phytochemical screening of the botanicals revealed the presence of certain organic compounds including phenol and phytol. The prospects of combined powdered extracts of Bridelia
ferruginea and Hyptis suaveolens as efficacious integrated nematode management strategy in soybean production is intriguing.