Randa H. Elsalahi
National Center for Research, Sudan
Title: Effect of Benomyl on soil Indigenous bacteria, actinomycetes and fungi and their capability of degrading the fungicide in two soil types in Sudan
Biography
Biography: Randa H. Elsalahi
Abstract
Two laboratory experiments were conducted to investigate the effect of different concentrations of Benomyl fungicide on the numbers of the main groups of soil micro flora and to elucidate percent fungicide degradation in sandy loam and clay loam soils in Sudan. Benomyl was applied in four concentrations; 0.032, 0.8, 3.2 and 8.0 mg/g soil. Counts of microorganisms in Benomyl treated soils were determined at 7, 15, 30 and 240 days’ intervals. Benomyl residue was determined at the same intervals using RP C18- HPLC. Results revealed the suppression of fungal flora in both soil types immediately after the first week of incubation. Numbers of organic nitrogen using bacteria increased earlier (15 days) in sandy loam soil compared to clay loam soil (30 days). While inorganic nitrogen using bacteria increased in numbers by Benomyl application at 15 days’ interval and then decreased in numbers up to the end of incubation period especially at the highest concentrations in both soil types. Benomyl completely suppressed actinomycetes in clay loam soil and was found to cause fluctuating effects on their numbers in sandy loam soil. Degradation of Benomyl at the first three concentrations started earlier in sandy loam soil compared to clay loam but the highest degradation values were recorded in clay loam soil after 240 days of incubation. At the highest concentration tested Benomyl underwent higher and faster degradation in clay loam soil compared to sandy loam.