163 – 171 of 715 Results
21-2020 Effect of Cover Cropping Systems on Dryland Soybean Plant-vigor, Growth, and Yield
Nearly 60% of all soybeans grown in Mississippi are produced in a dryland environment. Inconsistent yields are a common problem for dryland soybean production due to irregular rainfall events during the growing season. It has been suggested that the use of cover crops might help alleviate some of the issues during the growing season through improved water infiltration, soil moisture retention, nutrient availability, and enhanced soil organic matter. Currently less than 2% of cropland in Mississippi utilizes cover crops. Therefore, the goals of this project were to evaluate various cover crops in conjunction with different planting dates and nutrient sources to determine the optimal combination for integrating cover crops into a cropping system.
18-2020 Biochar seed coating as an approach for preventing root infection of soybean seedlings by Macrophomina phaseolina and other soil fungi
The proposed research is to determine if biochar, which is a type of charcoal produced as a soil amendment, can be used to protect germinating soybean seeds from root infection by fungi that use (-)-botryodiplodin or other charcoal-binding mycotoxins to facilitate root infection by killing meristematic tissue. Two approaches that can be envisaged for using biochar are (i) by addition to the soil around the seed at planting and (ii) by incorporating biochar into a bioplastic-based seed coatings. Of these approaches, biochar-containing seed coatings are considered the most practical approach. Successful application of biochar in seed coatings would be expected to significantly reduce seed losses for Mississippi soybean growers, thereby reducing costs and improving profitability.
15-2020 Shanmugam Determining Management-related Factors that Impact the Severity and Incidence of Soybean Taproot Decline
Soybean taproot decline (TRD), an important soilborne root disease, is shaping up to become one of the major diseases facing soybean producers in Mississippi, and beyond. TRD has been increasing in Mississippi since the first reports more than 12 years ago but yield losses and economic damages have yet to be accurately quantified. With an increased understanding of the relationships involved, there is an opportunity for increased field suppression due to more informed selection of management practices and scientific monitoring of the results. Our aim is to understand how management practices in Mississippi soybean production systems (e.g., early-planting, precision seed placement, irrigation systems, residue management) relate to the occurrence of TRD in order to verify the effects of altering management practices, and to determine the potential for enhancing the disease suppressive ability of these endemic soils. The aim is to broaden the range of cost-effective practices for TRD suppression that are amenable to incorporation into Mississippi soybean production systems.
12-2020 Tagert Managing Iron Deficiency Chlorosis (IDC) Through a Cropping System Approach
There have been numerous studies in other states on different management strategies to address IDC and the factors that are causing symptomology and intensity of symptoms. One particular study indicated that using an oat companion crop increased soybean yields 5 - 18 bushels/acre. The theory behind this approach is to use the companion crop to reduce soil nitrate levels. It has also been noted that tractor wheel tracks in Mississippi and Minnesota fields have greener plants in the fields due to soil compaction. Soil compaction is considered a poor management system for farmers and reduces yields. However, tractor wheel compaction reduces soil nitrate levels in that area and increases subsequent nitrogen loss by denitrification. Usually in fields with low soil nitrate levels, plants are not as green. In the case of iron chlorosis, though, the opposite occurs because higher soil nitrate levels make iron chlorosis symptoms worse. Some researchers have indicated seeding rates (200,000 – 250,000 plants/acre) with wide row spacing in chlorosis-prone areas have increased yields. The theory is more plants per row foot will help utilize nitrate and reduce IDC issues. Variety selection has been the most common method for reducing losses from IDC, but with all of the information studied in the IDC subject area, no single researcher has implemented a multiple cropping system approach.
10-2020 Understanding in-field soil moisture variability and its effect on irrigation Final Report
Site-specific irrigation decisions require information about variations in soil moisture within the rooting depth actively being used by the crop. Producers have been using soil moisture sensors to make irrigation decisions, and it has been shown that soil moisture sensors can reduce water use without reducing yields. There are still unanswered questions on improving efficiency with soil moisture sensors based on density and location of sensors within a field. This three-year study used sensors to evaluate the spatiotemporal variability of soil moisture across an 18-ha production field in a corn/soybean rotation.
31-2019 Evaluation of soybean breeding lines for resistance to Phomopsis seed decay and for high seed germinability final report
Phomopsis seed decay (PSD) of soybean is a major cause of poor seed quality in most soybean production areas, especially in the mid-southern region of the United States. Breeding for PSD-resistance is the most cost-effective long-term strategy to control this disease. In recent years, new sources of resistance to PSD have been identified (Li et al., 2011, 2015), and lines with high germinability have also been identified (Smith et al., 2008). Crosses were made between these new sources, resulting in the development of multiple heterogeneous breeding lines with the potential of having both high germinability and resistance to PSD. Seed quality assays, including seed plating for percentage of Phomopsis seed infection and standard germination tests were conducted following the harvest of plants selected for improved agronomic traits.
Principles of Efficient Agricultural Irrigation--Irrig. Assoc.
The Irrigation Association has published an article titled "Principles of Efficient Agricultural Irrigation" that covers the basics of crop irrigation.
20-2020 Bond Weed Management Programs in Mississippi Soybeans Annual Report
Glyphosate-resistant Palmer amaranth is the most troublesome weed in Mississippi soybean. Palmer amaranth competes for nutrients, water, light, and space because of its rapid, upright growth habit and allelopathic properties. Barnyardgrass is one of the more problematic weeds in U.S. soybean production. Recently, Mississippi and Tennessee became the first states to confirm GR barnyardgrass. Mixing herbicides representing different modes of action provides the potential for increased weed control and a reduction in application costs. However, some components of herbicide mixtures can synergize or antagonize others. It is important to identify effective programs for broad-spectrum weed control in these technologies. Recommendations for weed control in Mississippi soybean will originate from this research.
14-2020 Wilkerson Organism Affecting Seed Quality and Fungicide Efficacy Annual Report
Infection can be more severe when harvest is delayed and environmental conditions continue to be warm and humid during the growth stages that precede harvest (R7 and R8). As a means of reducing Phomopsis seed decay in subsequent seasons the current management strategies include crop rotation with non-hosts, tillage, fungicide applications during pod-fill, and resistant cultivars. However, information regarding efficacy of fungicide applications and cultivar resistance within the current commercial offerings is limited. The objectives of this research will improve soybean resistance to reduced grain quality by screening germplasm and developing new and improved breeding lines, and develop best management practices to address the soybean production issues associated with reduced grain quality.