Crop, Forage and Turfgrass Management最新文献

Western ragweed (Ambrosia psilostachya DC) is one of the most common perennial, native forbs of western US rangelands. Cattle consume small quantities of western ragweed in their diets when present in the forage sward, and forage nutritive value tends to be greater than the associated grass component in those swards. Yet, many producers view western ragweed as an undesirable forb in rangelands. We conducted a study over two years to compare vegetative and stocker animal productivity in pastures that were either sprayed with dicamba at 6 oz/acre (0.19 lb a.i./acre) for western ragweed control or were left unsprayed. Pastures started the study with high western ragweed densities (>9 western ragweed plants/ft²) before pasture treatment, and spraying with dicamba significantly reduced western ragweed density and yield compared to unsprayed pastures (0.2 vs. 3.5 ragweed plants/ft², and 0 vs. 206 lb/acre, respectively). Grass production and total vegetation production were similar between treatments. Crude protein and total digestible nutrients of western ragweed was greater than grass at all mid-season and end of season sampling dates both years. Stocker animal gain was not different between pastures sprayed for ragweed control and pastures left unsprayed in either year, nor when averaged over the two years (189 vs. 188 lb/head, sprayed vs. unsprayed, respectively). Beef production per acre was also similar. The spray treatment was an added expense that did not result in greater total forage, grass, or animal production. With natural fluctuations in western ragweed population densities due to weather patterns, producers will likely experience little benefit from spraying for western ragweed alone in pasture.

Farmers are making decisions every year under weather variability, input cost fluctuations, and commodity price uncertainty. Traditional replicated field trials cannot recommend actionable knowledge at the field level accounting for all sources of variability and uncertainty. Decision support tools aim to fill the gap that traditional agricultural research cannot. Agroptimizer (www.agroptimizer.com), a machine learning cloud-based decision support tool (DST) has a user-friendly interface that users can easily input field and management information and was designed to identify optimum corn and soybean cropping systems, for maximum yield and profit, across the United States. The recommended management practices of the DST were compared against cropping systems that were generated by University of Wisconsin researchers (called typical hereafter) across Wisconsin between 2021 and 2023. Agroptimizer recommendations for corn resulted in similar yield and profit compared to typical. For soybean, Agroptimizer recommendations resulted in increased yield and similar profit compared to typical. There was no downside yield and profit risk difference between Agroptimizer-based and typical cropping systems for both crops. Overall results showed that Agroptimizer successfully identified cropping systems that resulted in high yield and profit for both crops suggesting that in the absence of available expert recommendation, it can provide management practices with high yield and profit potential. Agroptimizer is being constantly updated and will be evaluated in additional locations across the United States in subsequent years.

Recent research has demonstrated the ability of a fenclorim seed treatment to reduce rice (Oryza sativa L.) injury to acetochlor. However, all studies were conducted on silt loam soils and have not evaluated rice tolerance or weed control on clay soils. Experiments were initiated in 2021 and 2022 at the Northeast Research and Extension Center near Keiser, AR, to determine rice response and the effectiveness of delayed-preemergence (DPRE)-applied microencapsulated (ME) acetochlor (1.1, 1.7, and 2.3 lb ai acre⁻¹) when applied to a clay soil with and without a fenclorim seed treatment at 0 or 2.5 lb ai 1000-lb⁻¹ of seed. Averaged over the fenclorim seed treatment, acetochlor at 1.1 and 1.7 lb ai acre⁻¹ caused similar injury levels to rice; however, barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] control increased at 1.7 lb ai acre⁻¹, eliciting 19% injury to rice and 82% barnyardgrass control at 28 days after emergence (DAE). Palmer amaranth (Amaranthus palmeri S. Watson) control ranged from 82% to 93%. Additionally, fenclorim did not influence barnyardgrass or Palmer amaranth control, but it did reduce rice injury and increase shoot density, plant height, and rough rice grain yield. At 14 and 28 DAE, fenclorim at 2.5 lb ai 1000-lb⁻¹ of seed (averaged over acetochlor rates) reduced visible rice injury from 61% to 13% and 40% to 8%, respectively. Results from this study indicate ME acetochlor could be successfully applied to rice grown on a clay soil when a fenclorim seed treatment is used, providing producers a new site of action for use in U.S. rice production.

Weeds are a consistent nuisance, and intrusion can impact turfgrass in multiple ways. On sports fields, weed pressure can disrupt surface consistency, which can impair playability, performance, and lead to injury risk (Aldahir & McElroy, 2014; Brosnan et al., 2014; Straw et al., 2018). Surface inconsistency then can diminish the benefits that sports participation can have on individuals' health and well-being (Eigenschenk et al., 2019).

Controlling weeds in turfgrass can involve cultural practices, mechanical removal, and application of herbicides. While cultural practices and mechanical removal can be effective for minimizing weeds, eliminating weeds in turf frequently requires the use of herbicides (Hahn et al., 2020; McElroy & Martins, 2013). The use of herbicides though has been challenged by urban residents and decision makers due to concerns around human and environmental impacts resulting in increased regulations or usage bans (Camargo et al., 2020; Larson et al., 2010; Riches et al., 2020). However, a gap exists in understanding user perceptions of weed control methods, including herbicides, on sports fields. The primary goal was to survey adult sports field users to evaluate their views on herbicide use and other weed control measures concerning health and safety, playing surface quality, and aesthetics.

An online survey conducted from August to October 2023 was distributed via municipal and private recreational sports programs to reach adult sports field users in the Twin Cities Metropolitan Area of Minnesota. Participants were asked about the acceptability of weed presence in sports fields, and the amount of weeds that would impact their performance, safety, and enjoyment using a photo series (Figure 1). Additionally, participants were asked about weed control methods and their support for use, harmfulness to humans/environment, and effectiveness of the method; all questions were measured using a Likert-type scale (1 = strongly disagree, 7 = strongly agree). Demographic questions included age, gender, and recreational sports participation. Repeated measures analysis of variance, post-hoc Tukey's honest significant difference, and effect size analyses were conducted using Stata version 18 to assess differences between perceptions and weed control methods.

Two hundred forty-one completed survey responses were received. Participants had an average age of 30 years old (min = 18, max = 63), and the sample was 51% female and 49% male. Half of the participants played multiple sports (M = 2.5). The most common sports participated in were soccer (30%), baseball/softball (21%), kickball (18%), ultimate frisbee (14%), disc golf (11%), volleyball (9%), flag football (8%), tackle football (1%), and golf (1%).

Herbicide use on turfgrass is often needed for sports turf to maintain a safe, consi

The utilization of advantageous microorganisms as a biofertilizer has gained significant importance in the agricultural industry due to their potential contribution to food safety and the sustainable cultivation of crops. To evaluate the effect of nitrogen (N) fertilizer and co-inoculation with arbuscular mycorrhiza and rhizobium on the yield and yield component of chickpea (Cicer arietinum L.), a 2-year field experiment was conducted in 2020–2021 at the Agricultural Research Station of Ferdowsi University of Mashhad, Iran. The experiment was designed as a randomized block trial in factorial design with three replicates. The treatments included two levels of inoculation (noninoculated and inoculated with rhizobium and mycorrhiza) and application of different levels of N fertilizer (0, 25, or 50 kg ha⁻¹) at three growth stages (sowing, flowering, pod filling) as follows; F0 (0,0,0), F1 (25,0,0), F2 (25,25,0), F3 (25,25,25), F4 (50,0,0), F5 (50,50,0) and F6 (50,50,50), respectively. The results showed that seed inoculation and split N fertilization significantly increased yield and yield components in chickpea (Cicer arietinum L.). Seed inoculation showed the highest values for all traits studied compared to the noninoculated treatments. Moreover, among the fertilizer treatments, the highest values for plant height (41.8 cm), number of branches (9.1), number of grains per plant (17.8) and 100-grain weight (30.4 g) from F6 through the F3 treatment, were statistically similar. The results show that the effect of inoculation is more significant when a lower amount of N fertilizer is applied. Due to the health and environmental problems associated with chemical fertilizers, double inoculation and split application of N fertilizers at lower doses can be recommended.

Management of herbicide-resistant weeds can be improved by understanding the biology of resistant biotypes. While the majority of research has focused on female plants and seed production of Palmer amaranth (Amaranthus palmeri S. Watson) that are resistant to glyphosate, growth of male plants that are resistant to this herbicide has not been studied in detail. Additionally, interference of male versus female Palmer amaranth plants on cotton (Gossypium hirsutum) yield has not been reported. Plant height and biomass of male and female plants from a mixed population of glyphosate-resistant (GR) and glyphosate-susceptible (GS) plants was studied in North Carolina when grown season-long with cotton. Palmer amaranth height was less for GR male plants compared with GS males and both GR and GS females. Biomass of Palmer amaranth female plants was twice that of male plants irrespective of glyphosate resistance. Cotton yield was affected similarly by Palmer amaranth regardless of either gender or glyphosate resistance status. The implications of shorter GR male plants on pollen dispersal and ramifications on management of glyphosate resistance are not known. Results from these trials did not address implications of the height of male plants on fitness of GR resistance. Nonetheless, the finding that GR male plants were shorter in the field than GS male plants warrants a new look at this topic. Similar reductions for cotton yield in presence of both GR and GS biotypes and genders suggest that current yield loss assessments and management decisions do not need to consider these variables in Palmer amaranth populations.

Much of the corn acreage in New York state is harvested as corn silage and moisture assessment in the field is necessary for predicting harvest timing, but moisture estimation visually is very problematic, particularly for brown-midrib (BMR) hybrids. Our goal was to assess plant moisture relationships between BMR and conventional (CONV) corn hybrids, and to identify metadata that may assist in the prediction of whole plant moisture based on ear moisture estimations. In 2023, 202 corn fields were sampled in central New York from August 18 to September 27. A total of 41 different corn hybrids were sampled, with relative maturity (RM) ranging from 84 to 112 days, and 29% of the fields sampled were planted to BMR hybrids. Five representative plants per field were evaluated for plant height, ear length and width, and ear, stover, and whole plant moisture. Estimation of dry ear:stover ratio would be helpful in estimating whole plant moisture based on ear moisture. Ear length was not related to ear:stover ratio, while plant height and ear width were weakly but significantly correlated with ear:stover ratio. Ear moisture was highly correlated with ear:stover ratio (BMR, r = −0.95; CONV, r = −0.90), and highly correlated with whole plant moisture (BMR, r = 0.97; CONV, r = 0.98). Ear moisture averaged 1 to 2% units lower throughout the sampling season for BMR compared to CONV hybrids, while stover moisture averaged 1 to 2% units higher for BMR compared to CONV hybrids prior to optimum harvest moisture. Whole plant moisture declined about 0.6%units/day and was relatively similar across RM groups.

The bermudagrass stem maggot (BSM; Atherigona reversura Villeneuve) continues to damage bermudagrass [Cynodon dactlyon (L.) Pers.] pastures and hayfields throughout the southeastern United States each season. This management guide describes how to identify the damage to the forage and the bermudagrass stem maggot as a larva, pupa, and fly. Strategically timed pyrethroid applications reduce adult BSM populations and yield loss, but ongoing efforts are focused on developing integrated pest management plans that include cultural, physical, and biological suppression efforts. Research is ongoing to improve the effectiveness of insecticide applications and screen new modes of action to prevent resistance to the pyrethroids. However, long-term solutions will require development and release of tolerant bermudagrass cultivars to reduce the reliance on pesticides. Fine-stem bermudagrass lines are more susceptible to bermudagrass stem maggot damage than lines with thicker stem diameters. While ‘Tifton 85’ is still considered the standard to which we compare all other bermudagrass lines for BSM tolerance, there is still room for improvement. Genotypes currently under evaluation maintain the positive attributes of Tifton 85 while overcoming these challenges.

Previous research has shown that delayed planting of soybean (Glycine max L. Merr.) can reduce yield by as much as 30 lb ac⁻¹ day⁻¹ when planted after mid-June. In South Carolina, soybean is often planted in rotation with other crops or double-cropped behind cereal grains, which can lead to delayed planting and potential yield-loss. In this study, our objective was to determine the optimum planting date (PD) × maturity group (MG) combination on non-irrigated soybean yield in South Carolina, and to determine yield results for the entire planting window ranging from March through August. Four MGs (IV, V, VI, and VII) were planted on six PDs (March–August) in 2021 and 2022 in Florence and Blackville, SC. Data collection consisted of stand counts to determine final plant populations, end-of-season plant height and node counts, and yield/moisture content at harvest. The April, May, and June PDs resulted in the highest grain yield in Blackville in 2021 (averaging 76 bu ac⁻¹) and 2022 (averaging 42 bu ac⁻¹). The April and May PDs had the highest grain yield in Florence when averaged over both years (53 bu ac⁻¹). MG alone did not influence yield in Florence. However, MGs V, VI, and VII produced the highest yields in Blackville. The optimum PD × MG combination for yield was the May planted MG V in Blackville (88 bu ac⁻¹ in 2021 and 49 bu ac⁻¹ in 2022) and the April planted MG VII in Florence (65 bu ac⁻¹). Plant heights and node counts were highest when soybean was planted in April and May, and MG IV had the tallest plants overall due to its indeterminate growth habit. Results from this study suggest that planting soybean as early as late-March and as late as late-June may not reduce soybean yield in South Carolina as some late-March and late-June MG combinations met or exceeded the state yield average of 37 bu ac⁻¹ and did not differ statistically from April and May yields. This research has already impacted soybean growers in South Carolina as the crop insurance window for full coverage has been extended to include earlier and later PDs as of 2023.