WeedSOFT: Effects of Corn-Row Spacing for Predicting Herbicide Efficacy on Selected Weed Species

Dudenhoeffer

Crop Forage & Turfgrass Mgmt

et al. 2015

Corn (Zea mays L.) growers continue to show interest in identifying hybrids that offer high yields in narrow rows (<30 inches). Research evaluated the response of 10 phenotypically different hybrids planted at 30,000 and 36,000 seeds/acre in 15‐ and 30‐inch rows from 2011 to 2013 under dry growing conditions in Missouri. Precipitation was up to 35% less (2012) than the 10‐year average in the region during this research. Grain yields were 2.7% greater in 15‐inch rows than in 30‐inch rows when averaged over seeding rate and hybrid, with four of the 10 hybrids having greater yields in narrower rows. Drought affected overall yields, though an early‐maturing hybrid (P0461HR) and a drought‐tolerant hybrid (P1151AM) yielded more than the others. The higher‐yielding hybrids showed no yield difference based on row spacing. In 15‐inch rows, high ear placement and short plants of an early‐maturing hybrid (P0461HR) with average drought tolerance and a late‐maturing hybrid (33T57) with above‐average drought tolerance yielded more than a hybrid (P0621HR) with average drought tolerance and low ear placement, but yields were similar in 30‐inch rows. However, with both row spacings, late‐maturing, drought‐tolerant hybrids yielded more than hybrids with below‐average drought tolerance. Corn seeded at 30,000 seeds/acre (27,900 plants/acre at harvest) yielded 25% more in an extreme drought year (2012) than corn seeded at 36,000 seeds/acre (32,600 plants/acre at harvest), but no yield difference appeared in 2011 and 2013. Our study indicates that appropriate plant densities and hybrid selection were needed to successfully integrate narrow‐row corn into drought‐prone claypan soils.

Section: Modern Hybrids For Narrow‐row Corn Productionmentioning

confidence: 99%

Corn Hybrid, Row Spacing, and Seeding Rate Effects on Yield in Upstate Missouri

Dudenhoeffer

Crop Forage & Turfgrass Mgmt

et al. 2015

“…Several decision support systems to assist with herbicide use have been developed in recent years. Recommendations are typically based on yield loss estimates derived from weed densities, stage of development relative to the crop, and other environmental parameters (Hamill et al 2004;Hock et al 2007;Kudsk 1999;Kudsk and Kristiansen 1992;Minkey and Moore 1998); however, acceptance of these threshold-based decision support systems by growers has been low. There remains a desire to apply herbicides when weeds are present at densities below the economic threshold (M. J. Cowbrough, personal communication).…”

Section: Future Research Opportunitiesmentioning

confidence: 99%

Integrated Weed Management: Knowledge-Based Weed Management Systems

et al. 2008

The fundamental role of integrated weed management (IWM) is to provide a source of scientifically based knowledge from which growers can make informed weed-management decisions. The objectives of this article include (1) highlighting the essential knowledge base required for the success of an IWM cropping system, (2) identifying the barriers to acceptance of IWM, and (3) discussing the future research opportunities for IWM. The minimum knowledge base consists of four key components: the effect of tillage on weed population dynamics, the time of weed emergence relative to the crop, the critical period for weed control, and the concept of a harvest window. There are substantial barriers, however, that reduce the willingness of growers to adopt the components of an IWM cropping system. IWM systems can be perceived as unreliable resulting in increased risk to management. No direct economic benefit can be defined clearly nor has there been sustained support for the adoption of IWM. In the future, IWM must change from a descriptive to a predictive science. As new markets evolve for agricultural products, new quality issues will arise that may influence weed management. Environmental auditing of IWM systems in terms of ISO 14000 accreditation, total carbon credits, or energy use will provide an important template from which comparisons of alternative weed-control strategies can be assessed. IWM strategies must be developed to reduce the risk to management and to gain broader support from the crop-protection industry, growers, and government.

“…The timing of herbicide and fertilizer application could influence the competitive balance between weeds and the crop (Acciares & Zuluaga, 2006; Evans et al., 2003; Johnson & Hoverstad, 2002). Growing maize in narrow rows suppresses weeds and increases the consistency of weed control by herbicides (Hock, Knezevic, Johnson, Sprague, & Martin, 2007). Knowledge about the different factors affecting herbicide efficiency, such as the presence of weed species, the competitiveness of the crop, and variations in weather conditions, increases the accuracy and reliability of chemical control.…”

Section: Introductionmentioning

confidence: 99%

Integrated effects of nitrogen form, row spacing, and herbicide treatment on maize

et al. 2020

To control weeds and cultivate maize (Zea mays L.) with higher yields, production systems have to include more efficient forms of N and appropriate herbicide treatments. The timing of N release could give maize an advantage over weeds in competition for resources, whereas cultivation at lower row spacing often decreases weed biomass. Knowledge about the different factors affecting herbicide efficiency increases the accuracy and reliability of chemical control. This study tested the weed infestation level and the development and productivity of a recently developed maize hybrid grown with the application of several integrated practices. The maize hybrid was sown with application of standard and slow-releasing urea, with row spacing of 50 and 70 cm and treatment with either a pre-emergence or a post-emergence mix of herbicides. The numbers of plants of each weed species and their biomass were lower after the application of herbicides, although N form and row spacing produced no significant differences in the average weed infestation level for 3 yr. The postemergence herbicide treatment was more effective than the pre-emergence treatment for weed biomass reduction and enhancing maize yield parameters. The N form did not influence any measured yield parameter, whereas the 70-cm row spacing resulted in significantly higher harvest index and grain yield (0.45 and 9.19 Mg ha −1 , respectively) than the 50-cm spacing (0.43 and 7.36 Mg ha −1 , respectively). The wider row spacing resulted in higher grain yield through its interaction with N form and herbicide treatment. How to cite this article: Simić M, Dragičević V, Babić M, Brankov M, Filipović M. Integrated effects of nitrogen form, row spacing, and herbicide treatment on maize. Agronomy Journal. 2020;112:748-757.