Author: Erin S. ChadbournePublisher:
ISBN:
Category :
Languages : en
Pages : 118
Book Description
Effect of Selected Postemergence Herbicides on Glyphosate-resistant Soybean Growth, Development, and Yield Under Weed-free Conditions
Author: Erin S. ChadbourneInteraction of Postemergence Herbicides with Glyphosate in Soybeans
Author: David K. PowellPublisher:
ISBN:
Category :
Languages : en
Pages : 368
Book Description
Field and greenhouse experiments were conducted in 2008, 2009, and 2010 to evaluate the efficacy of glyphosate combined with other broadleaf herbicides on herbicide-resistant and -susceptible weeds in Illinois. Although this research supports an improvement in control of glyphosate-resistant common waterhemp with the addition of PPO-inhibiting herbicides to glyphosate, the overall herbicide efficacy was still somewhat variable with evidence for environmental conditions that may alter efficacy of the tank mixtures. Thus, the use of preemergence, soil residual herbicides are still justified to reduce reliance on these postemergence herbicide mixtures for weed control in soybean and ultimately deter further selection of common waterhemp populations resistant to glyphosate and PPO-inhibiting herbicides.
Weed Control, Soybean Injury, and Soybean Yield Effects of Common Postemergence Herbicides
Author: Comfort M. AtehDynamics of Early-season Weed Management and Soybean Nutrition
Author: Nick T. HarrePublisher:
ISBN:
Category :
Languages : en
Pages : 182
Book Description
The popularity of growers using only postemergence (POST) herbicides for weed management in soybean was enabled by the commercialization of glyphosate-resistant soybean. Field experiments were conducted across four sites throughout southern Illinois in 2012 and 2013 to study the influence of early-season weed management strategies on soybean nutrient accumulation, grain yield parameters, and the acquisition of nutrients by broadleaved and grass weeds. Increasing periods of weed competition duration were established by removing weeds at heights of 10, 20, 30 or 45 cm with glyphosate. A weed-free treatment utilizing a comprehensive soil residual and POST herbicide program was included to implement a weed-free comparison. Two standard herbicide management strategies that simulate common grower practices were also evaluated for comparison: flumioxazin PRE followed by glyphosate POST and two sequential POST glyphosate applications. Averaged across all 11 mineral nutrients analyzed in this experiment, broadleaved weeds accumulated 149 and 108% more nutrients than grasses in 2012 and 2013, respectively. Competition from 20-cm weeds reduced the acquisition of N, P, Ca, Mg, S, Fe, B, Cu, and Zn by soybean in 2012; these nutrients in addition to K and Mn were reduced by the same level of competition in 2013. N and Fe were the nutrients in soybean most notably impacted by weed interference. Reductions in soybean grain yield were the result of competition with 30-cm weeds in 2012, and 10-cm weeds in 2013; while, both standard herbicide regimens yielded less than the weed-free treatment in 2013 only. Additionally in 2013, average soybean seed weight and grain oil content was reduced when weeds were not removed before a height of 10 and 20 cm, respectively. The rate of decomposition and nutrient release was measured for waterhemp and giant foxtail desiccated by glyphosate at heights of 10, 20, 30, and 45 cm in two southern Illinois soybean fields. Weed biomass was grown under greenhouse conditions to ensure homogeneity and litterbag methodology was utilized to track in situ mass and nutrient losses, expressed as a decay constant (k) regressed over time according to the single exponential decay model. The effect of specie and height both had a strong influence on the intrinsic properties of the weed biomass and the associated rate of decay. Concentrations of the recalcitrant cell wall components (cellulose, hemicellulose, and lignin) were generally greatest as weed height (plant age and development) increased and with giant foxtail compared with waterhemp. Ca, Mg, and S concentrations were greater in waterhemp, while N was greater in giant foxtail. N and K concentrations decreased with increasing weed height. After 16 weeks, 10-cm waterhemp and giant foxtail detritus had lost 10 and 12% more mass compared to the 45-cm height. Decomposition rates revealed mass loss was highest for 10-cm waterhemp (kD = 0.022) and lowest for 45-cm giant foxtail (kD = 0.011) and this process was negatively correlated to the overall amount of cell wall constituents (r = -0.73). Nutrient release rates followed a similar trend in that shorter (younger) weeds and waterhemp liberated nutrients more readily. Across all tested plant material, K was the nutrient most rapidly released, whereas, Ca was the most strongly retained nutrient. Although the pressing challenge of managing herbicide-resistant weeds justifies the implementation of early-season weed control tactics, this research suggests there are ancillary benefits that are provided by this strategy. The use of a robust, broad-spectrum soil residual herbicide program in conjunction with timely POST applications provides the foundation for early-season weed management, thereby minimizing non-crop nutrient use and enhancing the nutrient acquisition capacity in soybean. This strategy facilitates more sustainable crop production by requiring fewer supplemental nutritional inputs while also protecting grain yield. (Abstract shortened by UMI.)
Glyphosate with and Without Residual Herbicides in No-till Glyphosate Resistant Soybeans
Author: Karen Ann CorriganEffect of Selected Postemergence Herbicides on Growth, Nodulation, and Nitrogen Fixation of Soybeans (Glycine Max)
Author: Ozair Ahmad ChaudhryPublisher:
ISBN:
Category : Plants
Languages : en
Pages : 68
Book Description
The Economics of Glyphosate Resistance Management in Corn and Soybean Production
Author: Michael LivingstonPublisher: CreateSpace
ISBN: 9781512272161
Category :
Languages : en
Pages : 52
Book Description
Glyphosate, known by many trade names, including Roundup, is a highly effective herbicide. Widespread glyphosate use for corn and soybean has led to glyphosate resistance, which is now documented in 14 weed species affecting U.S. cropland, and recent surveys suggest that acreage with glyphosate-resistant (GR) weeds is expanding. Data from USDA's Agricultural Resource Management Survey (ARMS), along with the Benchmark Study (conducted independently by plant scientists), are used to address several issues raised by the spread of GR weeds. Choices made by growers that could help manage glyphosate resistance include using glyphosate during fewer years, combining it with one or more alternative herbicides, and, most importantly, not applying glyphosate during consecutive growing seasons. As a result, managing glyphosate resistance is more cost effective than ignoring it, and after about 2 years, the cumulative impact of the returns received is higher when managing instead of ignoring resistance.
Bioregulator and Postemergence Herbicide Combinations and Their Effects on Phenolic Content and Yield of Soybeans
Author: Deborah J. MeierPublisher:
ISBN:
Category : Plants
Languages : en
Pages : 236
Book Description
Research Report
Author: Weed Management, Yield, and Economic Return on Investment of Six Soybean Systems in Conventional- and No-till
Author: Matthew C. GeigerPublisher:
ISBN:
Category : Agricultural ecology
Languages : en
Pages : 216
Book Description
Shifts toward herbicide resistant weed populations in row crop agriculture is a widespread epidemic. Sequential applications of EPSPS synthase-inhibitors, acetolactate synthase-inhibitors, and other herbicide site-of-action groups, have led to the selection and spread of herbicide-resistant weed biotypes (Powles, 2008; Tranel and Wright, 2002). New soybean systems with resistance to auxin herbicides, along with proprietary herbicide formulations, have been developed to control these herbicide-resistant weeds in soybean production. These new technologies will be compared in both conventional- and no-till with technologies which have been available for several years, in the aspects of weed control, yield, and economic return on investment (EROI). In both 2016 and 2017, when using preemergence (PRE) followed by postemergence (POST) herbicide programs, there were few differences in weed control between the six soybean systems. Adequate grain yield was provided by all soybean systems when proper herbicide programs were used. EROI was the highest when optimum yields were achieved, regardless of treatment cost.