Crop, Forage and Turfgrass Management最新文献

Waterhemp [Amaranthus tuberculatus (Moq.) J.D. Sauer] is one of the most problematic weeds in soybean [Glycine max (L.) Merr.] production in the Midwestern United States. In recent years, the adoption of soybean resistant to dicamba, 2,4-D, and/or glufosinate have enabled the use of these herbicides to improve control of problematic weeds. Field experiments were conducted in Indiana in 2021 and 2022 to determine effective herbicide programs for controlling a waterhemp population resistant to herbicides in Weed Science Society of America (WSSA) Groups 2, 4, 5, 9, and 14. Two soybean varieties, one resistant to dicamba, glufosinate, and glyphosate, and the other resistant to 2,4-D, glufosinate, and glyphosate were evaluated. Preemergence applications included an auxin herbicide, either 2,4-D or dicamba, applied with pyroxasulfone and flumioxazin. Postemergence applications included combinations of 2,4-D or dicamba, glyphosate, and glufosinate. No more than 6% soybean injury from all postemergence applications was observed in 2021 and no injury was observed in 2022. By 21 days after the second postemergence application, two-pass herbicide programs increased waterhemp control by at least 30% compared to one-pass systems. Comparatively, two pass postemergence programs were more effective in 2021 and preemergence followed by postemergence programs were more effective in 2022. Control of waterhemp with 2,4-D and dicamba was similar in 2021; however, 2,4-D was more effective than dicamba in 2022, indicating the diminishing utility of dicamba in this field. Results from this study suggest that effective control of multiple-resistant waterhemp population is most likely achieved with two-pass herbicide programs that include 2,4-D tank-mixed with other effective herbicides, such as glufosinate.

Flooding and waterlogging from strong storms can negatively affect corn (Zea mays L.) growth and yield. Ensuring adequate nitrogen (N) supply after waterlogging is key to optimizing corn yield, though limited evaluations of enhanced efficiency fertilizers have been conducted in conjunction with waterlogging conditions. The objective was to quantify how different pre-plant incorporated N sources and post-emergence waterlogging affect corn N uptake, yield, and efficiency of applied N. A split-plot randomized complete block design was conducted in two locations from 2021–2023. Waterlogging regimes (0 or 4 days) were implemented by applying water at the V4–V6 growth stage. Pre-plant incorporated N source was the subplot factor consisting of a non-fertilized control or 200 lbs N acre⁻¹ applied as urea (U; 46–0–0) or urea-ammonium nitrate (UAN; 28–0–0) alone or combined with either nitrapyrin or N-(n-butyl) thiophosphoric triamide (NBPT), and polymer-coated urea (PCU, 44–0–0). The optimum ear leaf N concentration at R1 (2.75%–3.50%) was only achieved with U and PCU when waterlogging occurred. Waterlogging reduced grain yield by 9% to 25%, while N source (across waterlogging treatments) increased grain yield over the non-fertilized treatment by 14% to 45% or 236% to 343%, depending on location. Grain yield was optimized with U, PCU, and U with nitrapyrin regardless of waterlogging condition. Dry fertilizer sources also resulted in higher partial factor productivity compared to UAN treatments. These results suggest that dry N sources of U, PCU, or U with nitrapyrin should be considered in regions prone to waterlogging to optimize corn grain yield.

A common method of re-establishing putting greens following winterkill is to vertically mow and apply seed. There is very little information available on when spring seeding should occur and what creeping bentgrass (Agrostis stolonifera L.) cultivars should be used in the field. The objective of this study was to evaluate spring establishment rate of creeping bentgrass and annual bluegrass [Poa annua var. reptans (Hauskn.)] seeded three consecutive weeks in the spring of 2023 and 2024. Seed entries included creeping bentgrass cultivars, ‘Penncross’, ‘Pure Distinction’, ‘Declaration’, ‘Penn A-4’, one annual bluegrass seed, ‘Two-Putt’, a 50/50 (w/w) Pure Distinction and Two-Putt mix, and a non-seeded control. To simulate winterkill, non-selective herbicide was applied twice prior to seeding and plots were vertically mowed in two directions. Seed was applied at 2 lb 1000 ft⁻² three consecutive weeks once soil temperatures reached a daily average of 45°F at a 2-inch depth. Digital image analysis was collected for 5 weeks during the establishment period to assess turfgrass cover. Seeding date one had the highest turfgrass cover at the beginning of data collection for two rating dates in 2023 and one rating date in 2024. By the end of the study, seeding date was not significantly different. In 2023, Penn A-4 and Penncross had the highest turfgrass cover, but differences were small and biologically insignificant. In 2024, there were no differences among creeping bentgrass cultivars, and in both years, Two-Putt annual bluegrass was one of the worst establishing entries.

Maize (Zea mays L.) is an important crop globally, including in Ethiopia, where it plays a significant role in food security. However, fungi, particularly Fusarium species, pose significant threats to food safety and security worldwide. Among these fungi, the Fusarium graminearum species complex (FGSC) is a major pathogen that causes Gibberella ear rot (GER) in maize. In addition to reducing yield, FGSC pathogens produce harmful mycotoxins, primarily deoxynivalenol (DON), Deoxynivalenol-3-glucoside (DON-3G), zearalenone (ZEN), and nivalenone (NIV). Thus, disease assessment was conducted to identify the distribution of GER, as well as the associated production practices and biophysical factors, affecting the disease development in southern and western Ethiopia during 2020 and 2021. This study also aimed to analyze the concentrations of mycotoxins (DON, DON-3G, and ZEN) in field samples. The survey revealed significant differences (p < 0. 001) in GER intensity and grain yield loss across the assessed zones. The highest disease severity and corresponding estimated grain yield loss were observed in West Wallaga, while the Gurage zone had the lowest disease severity and yield loss. All the maize samples (n = 52) contained ZEN, while more than 75% of the samples tested positive for DON and DON-3G. Mycotoxin contamination levels ranged from 1 to 4291 µg kg⁻¹ (a mean 635 µg kg⁻¹) for DON, 1 to 1554 µg kg⁻¹ (a mean 174 µg kg⁻¹) for DON-3G, and 6 to 2236 µg kg⁻¹ (a mean 202 µg kg⁻¹) for ZEN. The frequency and levels of mycotoxins in this study were greater than those reported in previous studies on maize in Ethiopia. This could be attributed to less adoption of the recommended production practices by most farmers in the area and varying environmental factors that could favor the disease. Moreover, 25% of the maize samples exceeded the European Union's recommended value for ZEN and DON in unprocessed cereals. The severity of GER disease was significantly and positively correlated with biophysical factors like insect and weed infestations, but significantly negatively correlated with production/agronomic practices such as the correct fertilizer applications and use of resistant/tolerant maize hybrids. The right sowing date and cropping methods also significantly influenced the variation in GER disease intensity among the maize farms. Furthermore, there was a strong positive association between disease severity and the concentrations of DON, DON-3G, and ZEN in maize kernels. Overall, the study highlighted the necessity for integrated approaches to manage GER and associated mycotoxins. The role of agronomic practices under varying environmental conditions is not fully understood, but implementing preharvest ear rot management strategies can help mitigate GER disease and the associated mycotoxin risks.

Green stem is a term used to describe abnormal or delayed senescence maturation patterns in soybean [Glycine max (L.) Merr.] where the stems of affected plants stay green even after pods reach physiological maturity. Green stem has been reported by agronomists throughout the United States, but it is generally more prevalent in the Southern United States. Green stem occurs when nutrient sink strength is weak, which can be associated with environmental stress, insect feeding, and some diseases. There is a genetic component to green stem development, and some varieties are more prone to green stem than others. Management options are somewhat limited, since by the time green stem is observed, most management choices will require delaying harvest, which reduces seed quality. Primary options include waiting to harvest until after a hard frost or using desiccant products prior to harvest.

Onion (Allium cepa L.) is a high-value vegetable crop in Ethiopia; however, its productivity remains far below the global average (8.8 vs. 19.7 t/ha). This yield gap is largely attributed to inadequate fertilization and suboptimal agronomic practices. The objective of this review is to assess the effect of different rates and combinations of farmyard manure (FYM) and NPS (nitrogen–phosphorus–sulfur) fertilizers on the yield and yield components of onion under Ethiopian conditions. Global and national research highlights that integrated nutrient management improves onion growth parameters, including plant height, leaf number, bulb size, and total yield. The combined application of FYM and NPS fertilizers enhances soil physical, chemical, and biological properties, contributing to sustainable productivity gains. In Ethiopia, the currently recommended rates 7–10 t/ha FYM and 242 kg/ha NPS have shown positive effects on crop performance. However, persistent challenges such as the variable quality of FYM, poor application techniques, non-site-specific recommendations, and limited farmer awareness undermine their effectiveness. Reviewed findings suggest that no single fertilizer type can fully address productivity constraints. Instead, the integration of organic and mineral fertilizers at optimal rates optimized to local conditions emerges as a promising approach. Future research should focus on identifying site-specific, economically viable nutrient combinations that can close the onion yield gap while enhancing soil health and long-term agricultural sustainability in Ethiopia.

Traditionally cultivated for its seeds, quinoa (Chenopodium quinoa L. Willd) is increasingly being explored as a dual-purpose (grain and forage) or forage crop in integrated crop–livestock systems, particularly on marginal soils. This study investigated the effects of plant growth regulators and their application timing on drought tolerance, herbage yield, and the nutritive value of quinoa under rainfed conditions in Türkiye over 2 years. The treatments involved the application of the plant growth regulators zeatin, brassinolide, and their combination. These were applied either as pre-sowing seed treatments, post-sowing foliar applications, or both. A control group with no growth regulator was included for comparison. The herbage yield of quinoa without growth regulator application ranged from 3.19 to 4.67 t dry matter ha⁻¹. The application of growth regulators significantly influenced agronomic and physiological parameters, reducing the time required for plants to reach maturity. Combined pre- and post-sowing applications resulted in taller plants, larger root diameters, and increased herbage yield compared to control plants. The growth regulator applications also improved physiological traits and nutritional parameters, such as leaf area index, net assimilation rate, crude protein content, and digestible dry matter of forages. These findings suggest that quinoa can be incorporated into crop rotations to help address the shortage of high-quality livestock feed. Additionally, the application of zeatin and Brassinolide has the potential to enhance quinoa establishment and production in marginal soils (e.g., dry, saline).

Relay intercropping (RIC) of soft red winter wheat (SRWW, Triticum aestivum L.) and soybean [Glycine max (L.) Merr.] offers potential benefits but requires optimized management. This 2-year study (2022–2023) evaluated the effects of soybean planting date and strip-tillage vs. no-tillage (ST vs. NT) on RIC soybean yield and assessed the impact of ST on wheat yield. Later-planted RIC soybean (May 19, 2022, and May 30, 2023) outyielded earlier-planted RIC soybean (April 29, 2022, and May 11, 2023) by 18.8 bushels per acre in 2022 and 20.1 bushels per acre in 2023. However, sole crop soybean yielded higher (∼50 bushels per acre) and had better economic returns. ST increased RIC soybean yield by 8.3 bushels per acre in 2022 and 1.8 in 2023 compared to NT. The experiment was also designed to isolate the effect of ST on wheat yield in RIC to help establish soybean rows. NT wheat outperformed ST wheat in both years, with yield reductions of 5.4 bushels per acre in 2022 and 14.8 bushels per acre in 2023 when ST was used. These results indicate that while ST benefits RIC soybean yield, it negatively affects wheat yield, highlighting a tradeoff in the system. Our findings suggest that later planting dates improve RIC soybean yield by reducing competition with wheat, but overall, sole crop soybean remains more productive and profitable.

Prior cropping sequence can have a major effect on populations of plant parasitic nematodes (PPN), peanut (Arachis hypogaea L.) yield, and financial return at the farm level. Effective crop rotation sequences can reduce PPN populations and reduce grower reliance on nematicides or fumigant. Recently, the root-knot nematode-resistant cultivar TifNV-High O/L was released. To determine the performance of this cultivar to PPNs in North Carolina, a cropping system trial that included 10 diverse rotation sequences from 2013–2020 was used that included rotation sequences that were favorable or unfavorable for maximum peanut yield. Peanut was planted in 2021 to determine the residual effects of the previous cropping sequence. Cropping sequence, cultivar, and metam sodium impacted peanut yield and population of PPN in soil. Fewer root-knot nematodes (Meloidogyne spp.) and less root injury from nematode feeding were observed for the cultivar TifNV-High O/L than Bailey II. Metam sodium decreased populations of lesion (Pratylenchus brachyurus Filipjev & Schuurmans-Stekhoven), ring (Mesocriconema ornatum Raski), root-knot, and soybean cyst (Heterodera glycines Ichinohe) nematodes in soil. With the exception of lesion nematode, response of nematodes and peanut to crop sequence, cultivar, and metam sodium was independent.

The bermudagrass stem maggot (BSM; Atherigona reversura Villeneuve) can severely damage bermudagrass [Cynodon dactylon (L.) Pers.] forage. Strategically timed pyrethroid applications significantly reduce BSM populations, but application timing needs to be further refined. Therefore, this study evaluated the use of a degree day model for timing insecticide applications to suppress the BSM. The research was conducted in a split plot design with two bermudagrass cultivars (‘Alicia’ and ‘Tifton 85’) and eight insecticide timing treatments ranging from 100 to 400 growing degree days (GDDs) plus an untreated control. The use of insecticide increased mean herbage accumulation and plant height more than the untreated control, but the timing of the insecticide applications did not affect either response (P < 0.01). All insecticide-treated plots had less BSM damage than the untreated control (P < 0.01). The canopies treated with insecticide at 100 and 200 GDD had a cooler micro-environment than those treated at 150 GDD, but all other insecticide timing treatments were not different from those treatments (P < 0.01). Tifton 85 accumulated more herbage, resulted in a taller canopy, and sustained less damage by the BSM than Alicia (P < 0.01). Canopy temperature did not differ between cultivars (P = 0.94). It was hypothesized that greater losses would have occurred in the earliest and latest insecticide treated plots based on feedback from area bermudagrass growers. However, it appears that day of application may be confounded with time of application in these reports. Future investigations should explore this interaction to further refine application timing.