Vol. 17 No. 1
Dynamics of soil microbial population as influenced by post-emergence application of herbicide mixtures
Author(s): S. K. RAJ, E. K. SYRIAC AND K.S. MEENAKUMARI
Abstract: Soil microorganisms are the important link in soil-plant-herbicide-fauna- man relationship; their activity and diversity may serve as the bio indicators of soil health following herbicide application. Hence, bacterial, fungal and actinomycetes population were enumerated at just before herbicide application [15 days after sowing (DAS)], 30 days after herbicide application (45 DAS) and 45 days after herbicide application (60 DAS) during kharif 2014 and rabi 2014-15, with an objective to study the impact of post- emergence application of two pre-mix herbicide mixtures, bispyribac sodium + metamifop at four doses 60, 70, 80 and 90 g ha-1, penoxsulam + cyhalofop butyl@120, 125, 130 and 135 g ha-1 on their population. The results revealed that compared to fungi and actinomycetes, bacterial population was found to be more at both the three stages of observation during both the years. Results also revealed that the tested dose of bispyribac sodium + metamifop (60, 70, 80 and 90 g ha-1) and penoxsulam + cyhalofop butyl (120, 125, 130 and 135 g ha-1) did not have any inhibitory effect on the population of bacteria, fungi and actinomycetes in direct seeded rice raised under puddled soil, implying the environmental safety of bispyribac sodium + metamifop and penoxsulam + cyhalofop butyl at their tested doses.