Crop, Forage and Turfgrass Management最新文献

The turfgrass system is a complex ecosystem where many soil-born arthropods dwell and co-exist. Often, turfgrass is threatened by many pests, such as billbugs (Sphenophorus spp.; Coleoptera: Curculionidae). Monitoring pests is an important strategy for effective management decisions. The four-way linear pitfall trap is commonly used to determine adult Sphenophorus spp. population in turfgrass; however, it is challenging to deploy, labor-intensive, and requires regular intensive maintenance. The objectives of this study were to (1) compare trap captures of Sphenophorus spp. and predators using solo-cup, pail, two and four-way linear pitfall traps, and (2) evaluate whether increasing the number of simpler traps improves capture efficiency of soil-dwelling arthropods. The captures of adult Sphenophorus spp. and carabids in the four-way linear pitfall trap were not consistently greater than those caught in the two-way linear or single solo-cup pitfall traps. The four and eight solo-cup pitfall traps captured more Sphenophorus spp. and most soil-active predators than the four-way linear pitfall trap. The pail pitfall trap was not efficient in capturing soil-active arthropods. Thus, increased numbers of solo-cup pitfall traps, at least four in a defined trapping area, could be an alternative to the four-way linear pitfall trap to sample or monitor Sphenophorus spp. or carabids. Deploying and maintaining a solo cup is much easier than a four-way linear pitfall trap.

Pasture systems in the northeastern United States are primarily comprised of cool-season perennial grasses. However, these systems are subject to a lag in forage production during the hot summer months. Incorporating warm-season annual grasses (WSA) into these forage systems may improve overall forage productivity, especially for producers with a limited land base. Therefore, the objective of this study was to compare the agronomic effect of WSA interseeded into orchardgrass (Dactylus glomerata L.; OG) and harvested at two different intervals. This study compared monocultures of OG to OG interseeded with sorghum-sudangrass (Sorghum bicolor × S. bicolor var. sudanense; SSG), pearl millet (Pennisetum glaucum L.; PM) or teff grass (Eragrostis tef L.; TEFF), harvested on either a 6- or 12-week interval. Results indicated that inclusion of WSA into OG did not improve total herbage accumulation or nutritive value beyond the OG monoculture at either harvest interval (p > 0.42). However, inclusion of WSA into OG did affect the proportion of OG in the stand at both harvest intervals (p < 0.01). The greatest effect was observed in plots interseeded with SSG, in which there was a ∼14% and ∼25% decrease in OG compared to OG monoculture plots when harvested on a 6- and 12-week interval, respectively. This study concluded that interseeding WSA into OG did not improve agronomic parameters of the stand compared to OG despite implementing different harvest frequencies. Future research is warranted evaluating the effect of warm-season annual legumes under similar conditions on the forage production of cool-season perennial grass pastures.

A 2-year experiment was conducted to evaluate the efficiency of Rhizobium bacteria and arbuscular mycorrhizal fungi in improving the growth and yield-related traits of grass pea (Lathyrus sativus L.) under different irrigation regimes (well-watered, mild water stress, and severe water stress). The results showed that unfertilized and water-stressed plants had the lowest performance, while plants inoculated with bioinoculants exhibited the best growth and yield. Water limitation led to a reduction in total chlorophyll content (20.3%), leaf area index (20.32%), relative water content (5.5%), seeds/pod (2.9%), pods/plant (20.23%), 1000-seed weight (2.92%), pod harvest index (0.72%), seed yield (24.5%), and biological yield (17.69%) compared to the well-watered treatment over 2 years. Rhizobium inoculation enhanced relative water content, seeds/pod, 100-seed weight, biological yield, and pod harvest index by an average of 9.25%, 4.82%, 4.81%, 16.78%, and 1.36%, respectively. Similarly, arbuscular mycorrhizal fungi inoculation increased relative water content (7.7%), seeds/pod (3.8%), 1000-seed weight (3.9%), pod harvest index (1.04%), and pod partitioning index (13.9%). These findings suggest that applying a combination of bioinoculants from different microbial groups can be an effective strategy for enhancing the productivity of grass pea under water-limited conditions.

Selecting an appropriate relative maturity group (MG) soybean [Glycine max (L.) Merr.] for a geographic location within a state is a crucial factor in ensuring profitable soybean production. Choosing an inappropriate MG can significantly reduce yield. We determined the probability of a relative MG yielding similar to or better than the other MGs by analyzing the yield data of full-season and double-crop soybean from Official Variety Tests (OVT) that were conducted across five locations in Virginia from 2006 to 2015. We considered MGs 3 to 5 for full-season and MGs 4 to 5 for double-crop soybean. Each MG was divided into three sub-groups: early (x.0-x.3), mid (x.4-x.6), and late (x.7-x.9). While MG significantly influenced soybean yield in most site-years with few exceptions, location affected the yield performance of a MG more for full-season than double-crop soybean. For full-season soybean, late MG-3 and 4 at Orange (38.3°N, −78.1°W), early to mid-MG-5 at Warsaw (38.0°N, −76.8°W), mid to late MG-4 at Painter (37.6°N, −75.8°W), and early to late MG-5 at Blackstone (37.1°N, −78.0°W) and Suffolk (36.7°N, −76.8°W), VA, had the highest outyielding capacity and probability to yield similar to or greater than other MGs. For double-crop soybean, late MG-4 consistently performed best across most locations, except for Blackstone, where early MG-5 was the optimal choice. Results offer valuable insights to soybean producers for confidently selecting the best MG with the greatest yield probability in their farming locations within Virginia. This analysis can serve as a model for similar investigations in other states using OVT data.

Wide-spread adoption of proximal sensors in crop health assessment requires understanding of changes in canopy reflectance during the growing season and associations among readings from different sensors. Chlorophyll meter reading (Soil Plant Analysis Development, SPAD), red normalized difference vegetation index (RNDVI), and red-edge normalized difference vegetation index (RENDVI) were measured for sugarbeet (Beta vulgaris L.), corn (Zea mays), sunflower (Helianthus annuus L.), soybean (Glycine max), and spring wheat (Triticum aestivum) throughout the 2021 growing season. Cumulative growing degree days (GDD) had a significant relationship with SPAD, RNDVI, and RENDVI. The correlation coefficient indicated SPAD was more associated with RENDVI (r = 0.73) than RNDVI (0.50). The R² values of multiple linear regression of SPAD and GDD with RNDVI and RENDVI were the lowest for spring wheat (0.33 and 0.52, respectively) and the highest for corn (0.94 and 0.95, respectively). For all major five crops grown in the Northern Great Plains, GDD showed a strong relationship with all three indices. For in-season crop health assessment based on vegetation indices, inclusion of GDD could be a useful predictor variable to develop a single model algorithm applicable for multiple crops at a regional scale.

Seed treatments are commonly used to protect most major crops in the United States from seed- and soil-borne pathogens. In winter wheat (Triticum aestivum L.) systems in the North Central United States, target pathogens include both true fungi like Fusarium spp. or Rhizoctonia spp. and oomycetes like Pythium spp. or Globisporangium spp. Potential benefits of seed treatments may include improved germination and emergence, protection against early season diseases, and improved plant vigor, but there is little recent research on the benefits of seed treatments in winter wheat in the North Central United States. Field experiments were established at 10 locations across Wisconsin, Indiana, and Michigan in 2021 and 2022 to evaluate the effect of seed treatments on winter wheat yield. The trial design was a randomized complete block with four replications. Treatments were a factorial of two varieties, Harpoon and Kaskaskia, and five seed treatments, non-treated control, Athena-R, CruiserMaxx Vibrance Cereals, Stamina F4, and Raxil Pro MD/Shield. The variety Harpoon resulted in greater yield and lower test weight than Kaskaksia. The only seed treatment to affect yield was Athena-R when applied to the Harpoon variety. No other seed treatment significantly impacted yield. Results of this study suggest that while seed treatments can provide yield protection, variety selection had a bigger role in overall yield potential.

Furrow-irrigated rice (FIR; Oryza sativa L.) has been grown in the upper Mid-South since the 1980s. Nitrogen use in FIR is less efficient than direct-seeded, delayed-flood rice due to the lack of a flood, which ultimately protects applied nitrogen (N) from nitrification and subsequent denitrification. If urea applied to FIR fields could be protected from nitrification, N use efficiency could be increased. To address this issue, a test was initiated in 2018 to determine the utility of a blended-urea product that included < 0.1% N-butyl-thiophosphoric triamide (NBPT), a urease inhibitor that is recommended on most urea applications to rice, and 0.85% dicyandiamide (DCD), a nitrification inhibitor. A control with no supplemental N application plus six different N management programs were tested as urea + NBPT with or without DCD. Analyses across six sites over 2 years suggested that DCD did not affect any of the variables measured, including total N uptake, recovery efficiency of N, rice grain yield, and rice milling yield. While this is contrary to some previous studies, the product used in the current study contained approximately 10 times less DCD than previous studies in rice. Therefore, out of the products tested, the authors recommend purchasing the lowest cost option.

No-tillage (NT) soybean [Glycine max (L.) Merr.] following corn (Zea mays L.) is a common practice in the United States. It reduces production costs associated with tillage such as labor, fuel, and equipment, in addition to providing environmental benefits such as reduced erosion and carbon emissions. However, in some situations, NT soybean seed yield can be reduced compared to conventional tillage (CT). The objectives of this study were to (i) quantify the effects of nitrogen, corn residue management, and tillage on soybean seed yield, and (ii) recommend optimal residue and nitrogen (N) management strategies for NT soybean following corn. The study was conducted at the University of Wisconsin-Madison Arlington Agricultural Research Station near Arlington, WI, during the 2022 and 2023 growing seasons. Treatments were tested in a randomized complete block design with four replicates. Treatments were combinations of NT, CT, N fertilizer application, and corn residue management (removed, chopped, or none). Soybean seed yield was not affected by removing corn residue. Applying 30 lbs N acre⁻¹ prior to NT planting soybean into corn residue and CT increased seed yield by 4.1 bu acre⁻¹ (6.1%) and 5.3 bu acre⁻¹ (7.8%), respectively compared to NT soybean planted into corn residue. The addition of a low rate of spring N can be a tool for producers to increase NT soybean seed yield rather than performing tillage.

North Carolina soybean [Glycine max (L.) Merr.] growers use a diverse range of row spacings, commonly between 7.5 and 38 inches. Research findings regarding the effect of row spacing on soybean yield have been inconsistent and influenced by factors such as planting date and environmental conditions. Although small-plot data from North Carolina often indicates that narrower row spacings lead to higher yields, growers have raised concerns about the potential benefits of wide rows when ripping is employed in environments exhibiting symptoms of subsurface compaction. Research was conducted over 2 years (2021–2022) in the Coastal Plain region to evaluate the effects of wide row ripped spacing (36 or 38 inches) compared to un-ripped narrower spacing (15 inches) on plant population, canopy cover, soil compaction, and yield across four environments. One of the environments included an additional treatment with an un-ripped drilled row spacing of 7.5 inches. Although seeding rates were calibrated similarly, the ripped wide-row spacing treatments led to lower achieved plant population, predominantly due to adverse seed bed conditions resulting in lower germination caused by the inline ripper. The un-ripped narrow row spacings (7.5 and 15 inches) consistently demonstrated 7–25% greater canopy cover than ripped wider spacings (36 and 38 inches) by the flowering stage (R1). Soil penetration resistance varied by row spacing in only two environments, with differences generally lacking agronomic significance (i.e., penetration resistance <2 MPa). Yield results indicated no significant effect of row spacing in three out of four environments; in the fourth environment, the un-ripped 15-inch row spacing yielded significantly more than both the un-ripped drilled and ripped wide-row soybeans. In the environments in this study, wide-row ripped treatments offered no agronomical advantage over narrow row un-ripped treatments.

Buckwheat (Fagopyrum esculentum) is a fast-growing plant that quickly produces a dense groundcover. The utilization of buckwheat as a cover crop in vegetable production could be beneficial to Georgia producers, however for successful adoption, weed control in the cover crop coupled with control of buckwheat volunteers must be achievable. A preemergence (PRE) and a postemergence (POST) experiment were each conducted three times in Ty Ty, GA (2020–2021) addressing these objectives. In the PRE study, acetochlor at 0.56 lb ai acre⁻¹ injured buckwheat up to 16% without negatively influencing growth, suggesting potential for use in buckwheat for weed control. Flumioxazin, fomesafen, halosulfuron, ethalfluralin and S-metolachlor lacked adequate buckwheat safety. However, flumioxazin at 0.05 lb ai acre⁻¹, fomesafen at 0.19 lb ai acre⁻¹, and halosulfuron at 0.02 lb ai acre⁻¹ were identified as effective options to manage volunteer plants, as control exceeded 80%. In the POST experiment, buckwheat injury from 2,4-D, clethodim, dicamba, glufosinate, glyphosate, halosulfuron, linuron, paraquat, and prometryn was evaluated, and when considering all evaluation parameters, paraquat (0.50 lb ai acre⁻¹) was the most effective option for the control of buckwheat. This was followed by glufosinate (0.59 and 1.17 lb ai acre⁻¹) and glyphosate (1.20 and 2.40 lb ai acre⁻¹). For potential applications over buckwheat for weed management, clethodim (0.12 lb ai acre⁻¹) was the only POST herbicide that provided adequate crop safety.