THE EFFECT OF GLYPHOSATE (N-PHOSPHONOMETHYL GLYCINE) A NONSELECTIVE HERBICIDE ON THE GROWTH OF SOME SELECTED SOIL FUNGI

Abstract

Glyphosate (n-phosphonomethyl glycine) is one of the leading non selective herbicide used in weed management throughout the world. However, the excessive use of this herbicide portends serious danger not only to human health but affects the environment. Aside these, the nature and survival of various groups of microorganism including soil fungi may be affected. Thus, this study is aimed to investigate the effect of glyphosate (n-phosphonomethyl glycine) herbicide on the growth of soil fungi isolates from Ahmadu Bello University botanical garden. Isolation of soil fungi was carried out using serial dilution techniques. Fungal identification was achieved via microscopic and macroscopic features. Varying concentrations of glyphosphate (0, 0.01, 0.1, 0.5 and 1 % v/v) was incorporated on sterilized Potato Dextrose Agar (PDA) and the isolated fungi were grown on it. Radial mycelial growth of fungal isolates observed at 24 hours interval at 28 ± 2 °C then calculated. All treatments were laid in Complete Randomize Design and replicated three times. The results obtained were subjected to one way analysis of variance (ANOVA). The result obtained showed that three fungi; Fusarium solani, Aspergillus niger and Trichoderma spp were isolated from the soil samples. The radial mycelial growth of Fusarium sp., Aspergillus niger and Trichoderma sp. were observed to be significantly reduced with increase in the herbicide concentration at P≤0.05. Therefore, the results of this study suggest that excessive use of herbicides reduces the growth of soil fungi as such has a negative effect on ecosystem forms and function.