Relationship of Glyphosate Application and Foliar Amendment on IAA-Producing Bacteria and Microbial Activity in the Rhizosphere of Glyphosate-Resistant Soybean. = 1 µm. Su-Jung Kim Department of Soil, Environmental, and Atmospheric Sciences. Outline. Introduction
Relationship of Glyphosate Application and Foliar Amendment on IAA-Producing Bacteria and Microbial Activity in the Rhizosphere of Glyphosate-Resistant Soybean
Department of Soil, Environmental, and Atmospheric Sciences
- Characteristics of Herbicide Glyphosate
- Foliar Amendments
- Deleterious Rhizobacteria (DRB)
- Indole-3-acetic acid (IAA) Effects of DRB on Weed Growth
- inhibition of 5-enolpyruvylshikimic acid-3-phosphate (EPSP) synthase
- Establishment of selected microorganisms in soil
- Enhancement of soil microbial activity
- Promotion or augmentation of the activities of critical soil enzymes, providing chelating substances and plant growth hormones, or supplementation of micronutrients (Kinnersley, 1993).
- Directly soil organic fraction by microorganisms
- Indirectly microbially synthesized metabolites such as phytohormones (Yamada and Xu, 2000).
- A nutritional supplement (21.0% total nitrogen in the form of urea)
- Designed for foliar application to increase crop yield.
- A biostimulant (boric acid, cobalt sulfate, copper sulfate, ferric nitrate, manganese nitrate, sodium molybdate, and zinc nitrate)
- Effects on rates of organic matter decomposition, soil microbial activity and mineralization.
- Management practices influencing soil microorganisms can affect crop yields and soil and environmental quality.
(Aldrich and Kremer, 1997; Kremer, 1987)
(Sylvia et al., 1998)
- Production of antibiotics, siderophores, and volatile compounds
- Parasitism, competition for nutrients and ecological niche
- Production of plant growth-promoting compounds, such as IAA, gibberellin, and cytokinin-like substances
- Compounds that stimulate plant growth (coleoptile tissue) in lower concentrations.
- In contrast, if the concentration becomes higher, the effect reverses and elongation of root and shoot is inhibited.
- Inhibit root growth in sugarbeet, blackcurrant, and morningglory
- Rhizobacteria from RR soybean cultured on half strength King’s B medium for 24-h and colonies counted.
- All counted plates were screened for IAA production using an in situ membrane assay (Bric et al., 1991).
- The incubation was conducted for 7 days with 5g of soil sample added 1ml of 5% glucose solution.
- CO2 efflux was measured with a Buck Scientific Model 910 gas chromatography via thermal conductivity detector (TCD).
Truspec® C/N Determinator
Buck Scientific Model 910 gas chromatogr-aphy
Lachat Quikchem Automated ion analyzer