African Journal of Immunology Research

African Journal of Immunology Research ISSN 2756-3375 Vol. 10 (1), pp. 001-011, January, 2023. © International Scholars Journals

Full Length Research Paper

Effect of Thiobencab and Penoxsulam Herbicides on Soil Microbial Population and Weed Control in Transplanted Rice

Alaa El-Dein Omara1* and Ahmed El-Ghandor2

1Agricultural Microbiology Dept., Soil, water and Environ. Res. Inst., Agric. Res. Center, Giza, Egypt.

2Rice Research Training Center, Field Crop Res. Inst., Agric. Res. Center, Giza, Egypt.

Accepted 04 July, 2022


The present study was to investigate the effect of two herbicides, thiobencarb 50% EC and penoxsulam 24% SC at their recommended field rates on soil microbial population at regular intervals i.e. 4th to 28th day after treatment, control of weeds and crop yield of transplanted rice. From each plot, five soil sub-samples were collected randomly and thoroughly mixed to form one composite sample. Results showed that the counts of total aerobic bacteria dramatically decreased with lapse of time after treatment which decreased from 4th days (6.01 log CFU ml-1), to 28th days (5.72 log CFU ml-1), during 2016 season, and from 4th days (6.39 log CFU ml-1), to 28th day (5.41 log CFU ml-1), during 2017 seasons. Also, the higher enumeration of N2-fixing bacteria, N2-fixing cyanobacteria and sulphate reducing bacteria were recorded from 4th to 12th, then decreasing to 28th days after treatment. Also, the counts of nitrifies bacteria, showed increased up to 16th days after treatment, then decreased thereafter. Also, high significantly affected by weed control treatments. Application of penoxsulam recorded the lowest value of Echnochlo crus-galli, Echnochlo colona and total weeds dry weight and achieved the highest number of panicles and grain yield as compared to weedy check, which gave the highest value of total weeds dry weight and the lowest rice yield characters. penoxsulam was observed to be less toxic than thiobencarb against microbial enumeration, control of weeds and increase crop yield of rice plant.

Key words: Microbial populations; Thiobencarb; Penoxsulam; Weeds; Rice