82 – 90 of 736 Results
31-2022 Impacts of charcoal rot (Macrophomina phaseolina) epidemiology on drought resistant soybean cellular metabolism and accompanying tissue microbiome for identifying alternative breeding targets under increasing environmental stress Annual Report
Critical stages of Mp infection in soybean initiate host responses that impact the metabolome. NMR is a rapid, inexpensive, and high throughput detection technique for determining metabolites that may indicate potential defense mechanisms within host plants. NMR spectra can be used to analyze the presence of a variety of compounds, from carbohydrates to amino acids. Many of these metabolites are associated with host cell responses, redox signaling, and energy production critical to plant growth. If hybrid resistance to Mp does occur through drought resistance, these metabolic biomarkers could provide targets for downstream genetic marker identification, thereby guiding new breeding strategies.
10-2022 Tagert Low-Cost Precision Agriculture Solutions for Advancing Irrigation Efficiency Annual Report
Variable-rate irrigation (VRI) is the precision agriculture practice of customizing irrigation amounts to different areas within a field based on the unique characteristics of each area. VRI can be used to compensate for and minimize problems associated with in-field spatiotemporal variability, especially that of soil moisture. However, the initial and maintenance costs of zone control VRI are often daunting, and the fear of managing these systems discourages farmers from adopting this technology. Sector control VRI systems are less expensive and easier to operate because only the revolution speed of the center pivot is adjusted, and most late-model center pivots can be programmed to travel at a different speed (and thus apply a different irrigation amount) in each of several pie-shaped sectors without additional control panel upgrades. On fields where the distribution of wetter/drier areas match well with the geometry of pie-shaped sectors, the use of sector control VRI is an ideal solution for advancing irrigation efficiency beyond what is possible with conventional uniform irrigation.
12-2022 Tagert Managing Iron Deficiency Chlorosis (IDC) Through a Cropping System Approach Final Report
There have been numerous studies in other states on different management strategies to address IDC and what factors are causing the symptoms and intensity. One study indicated that using an oat companion crop increased soybean yields in affected areas of a field. It has also been noted that soybeans planted in tractor wheel tracks in Mississippi and Minnesota IDC-prone fields have greener plants due to soil compaction. Soil compaction is considered a poor management system for farmers and reduces yields, but this tractor wheel compaction is thought to reduce soil nitrate levels by creating slightly anaerobic soil conditions that can result in nitrogen loss by denitrification.
66-2022 - Mulvaney Is Mississippi Irrigation Water Accumulating Salts in Soil and Potentially Limiting Soybean Growth Final Report
Entering preliminary MS water quality data into the Irrigation Water Analysis Results and Interpretation tool (NMSU, 2022) showed “severe limitations” due to sodium and bicarbonate levels, and “increasing problems” with irrigation water pH and total dissolved solids. However, these results must be interpreted alongside calcium, magnesium, total dissolved solids (TDS), and electrical conductivity (EC), data we do not have. Soybean is considered moderately salt-tolerant, with yield reductions expected when soil salinity >5 dS/m (Phang, et al., 2008; Papiernik et al., 2005) (response depends on the tolerance of individual varieties) but no soil salinity data from Mississippi soils are available. We propose to conduct a survey of water and soil across Mississippi along a chronosequence to determine if salt accumulation is a potentially yield-limiting factor for soybean production.
27-2022 Lowe Development of an Automated System to Incorporate Holes in Lay-Flat Irrigation Tubing During Initial Deployment in Mississippi Soybean Production Systems Annual Report
Performance of lay-flat irrigation tubing with respect to hole integrity is a crucial component of effective irrigation strategies that conserve water while maintaining crop yields. In addition, correct hole size is also important to this process and changes to them due to mechanical damage from over pressurization can be detrimental to maintaining the desired water output per row. Current hole insertion methodologies utilized for CHS are also crude and produce variations in flow that hinder optimization of water management.
21-2022 Effect of Cover Cropping Systems on Dryland Soybean Plant-vigor, Growth, and Yield Final Report
In Mississippi, no-tillage accounts for a slightly more than 620,000 acres, which is only 16.8% of all cropland. Another strategic factor in this system is cover crop termination and soybean planting date. Earlier plantings tend to have higher yields in Mississippi due to growth and development before drought conditions occur. Therefore, this study is focused on identifying production practices that will provide more consistent soybean yields while improving “soil health” with the following objectives: 1). Evaluate the effects of cover cropping systems on dryland soybean plant-vigor, growth, and yield; 2). Evaluate the effects of cover cropping systems on “soil health”; and 3). Determine the economic benefit of cover crops, source of fertilizer, and planting date on soybean production.
42-2022- fungicide efficacy, desiccant applications, and delayed harvest for soybean grain quality Final Report
The objectives of this research include identification of seed pathogen with ITS methods, fungicide efficacy to prevent growth of fungi, and evaluation of fungicide combined with desiccant application effects on seed quality. Experiments will be designed to identify the primary causal organism, and the response of the pathogen to fungicide application.
14-2022 Evaluating fungicide efficacy, desiccant applications, and delayed harvest for soybean grain quality Annual Report
Symptoms of Phomopsis seed decay include shriveled, elongated seed which appear chalky. 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.
43-2022 Safeguarding Mississippi soybean production from interactive heat and drought stress-induced yield and quality losses Final Report
Soybean yields have been inversely related to maximum summer air temperatures, with yield suppression of up to 6%, when the temperatures are above 85 °F during critical developmental stages under rainfed conditions. In addition to the various impacts observed, the detailed analysis highlights that combined drought and heat stress will amplify a negative effect on seed number, seed weight, and seed composition in current and future production systems. Not surprisingly, the highest yield and quality penalty are expected to occur when the heat and drought stresses coincide with flowering and pod filling in soybean (R1 to R6).