Crop, Forage and Turfgrass Management最新文献

Fraise mowing and hollow-tine aerification are disruptive cultural practices that alter soil physical properties. The objective of this study was to evaluate the effects of fraise mowing followed by hollow-tine aerification on soil physical properties in a Cecil sandy loam (loam) and a sand-capped soccer field (sand) beneath established ‘Tifway’ hybrid bermudagrass (C. dactylon x C. transvaalensis Burtt. Davy). Three fraise mowing depths (0.25, 0.5, and 1.0 inches) and hollow-tine aerification were applied in mid-June in two consecutive years. Turfgrass quality (TQ), thatch-mat depth, surface hardness, and divot resistance were measured in both soils. Saturated hydraulic conductivity (Ksat) was measured in the sand. All fraise mowing and hollow-tine aerification treatments resulted in unacceptable TQ for 2 to 6 weeks during the study. However, combining hollow-tine aerification with fraise mowing did not delay bermudagrass recovery. Thatch-mat depth decreased by ≥19% as fraise mowing depth increased but was unaffected by hollow-tine aerification. Fraise mowing did not affect Ksat; however, hollow-tine aerification increased Ksat by 54%. Surface hardness increased by ≤24% with increasing fraise mowing depths. Fraise mowing did not affect divot resistance in the loam. Divot resistance in sand decreased by 16 and 30% with the 0.5- and 1.0-inch fraise mowing depths, respectively. Hollow-tine aerification decreased surface hardness by 5% to 20% and divot resistance by 6% to 13%. When practiced concurrently, fraise mowing and hollow-tine aerification were complimentary and positively affected the soil physical properties in both soils.

The success of weed management decisions must be assessed not only in the short-term within season but also in the long-term over several seasons. This study investigated the effects of crop rotation and herbicide program structure on the population growth rates of Palmer amaranth (Amaranthus palmeri S. Watson) and common ragweed (Ambrosia artemisiifolia L.). A field experiment was conducted over a 3-year period in North Carolina to compare cotton (Gossypium hirsutum L.)–sweetpotato [Ipomoea batatas (L.) Lam.]–soybean [Glycine max (L.) Merr.], cotton–peanut (Arachis hypogaea L.)–soybean, cotton–tobacco (Nicotiana tabacum L.)–soybean, and cotton–soybean–soybean rotations and preemergence and postemergence herbicide application timings. Results showed that preemergence herbicide application in the soybean phase of the rotation reduced Palmer amaranth populations 79%. However, the preemergence herbicides were only effective at reducing weed populations for the current season, not beyond. Common ragweed population growth rate was highest after the first 2 years (λ = 1.63) of the cotton–tobacco–soybean rotation. Preemergence herbicides were effective in reducing common ragweed populations, particularly in rotations with cotton–sweetpotato and cotton–peanut. Soybean yields were similar across rotations ranging from 62 bu/ac to 68 bu/ac. Annual use of preemergence herbicides was essential to reduce Palmer amaranth populations. For common ragweed, the effectiveness of preemergence herbicides to mitigate population growth was reduced when poorly competitive crops were part of the rotation.

Late leaf spot disease [caused by Nothopassalora personata (Berk. & M.A. Curtis) U. Braun, C. Nakash., Videira & Crous] and southern stem rot (caused by Athelia rolfsii Sacc.) are economically important diseases in peanut (Arachis hypogaea L.) in North Carolina. Fungicides are often applied on a 14-day schedule when these pathogens are active during the cropping cycle to protect peanut yield. The fungicide pydiflumetofen has been shown to provide protection from leaf spot disease for longer than 14 days and is labeled for protection for 28 days. However, efficacy for this length of protection has not been documented in North Carolina. Research was conducted from 2019 to 2022 in North Carolina to compare incidence of leaf spot and canopy defoliation when chlorothalonil plus tebuconazole were applied approximately 21, 28, and 35 days after pydiflumetofen was co-applied with flutolanil or the commercial mixture of azoxystrobin and benzovindiflupyr. Pydiflumetofen does not control southern stem rot whereas flutolanil and azoxystrobin plus benzovindiflupyr do control this disease. Applying chlorothalonil plus tebuconazole 21 or 28 days after pydiflumetofen combinations was equally effective in protecting peanut from yield loss. In some cases, yield was lower when chlorothalonil plus tebuconazole were applied 35 days after pydiflumetofen combinations or when follow up fungicide was not applied. These data suggest that farmers in North Carolina can apply pydiflumetofen and expect 28 days of protection from late leaf spot. However, suppression of disease and peanut yield decreased in some cases when chlorothalonil plus tebuconazole does not occur until 35 days after pydiflumetofen combinations were applied.

Tobacco thrips (Frankliniella fusca Hinds) feeding can reduce peanut (Arachis hypogaea L.) yield and vector Tomato spotted wilt orthotospovirus (family Tospoviridae, genus Orthotospovirus). Visible injury caused by tobacco thrips feeding was recorded from 2013 to 2022 at one location in North Carolina when peanut was not treated with insecticide, when imidacloprid or phorate was applied in the seed furrow at planting, and when acephate was applied to peanut approximately 21 days after peanut emergence. A positive linear response for peanut injury caused by tobacco thrips was observed from 2013 through 2022 for non-treated peanut and peanut treated with imidacloprid and phorate. No difference in injury caused by tobacco thrips was noted for acephate. In a survey of farmers in 2022 cropping cycle, the most popular systemic insecticide applied at planting for this pest in North Carolina and Virginia was imidacloprid. The majority of farmers in these states indicated that control of tobacco thrips was more difficult now than in previous years, and that they made routine applications of acephate to control this pest.

Achieving high bread wheat (Triticum aestivum L.) productivity in a specific region is challenging without clear guidelines on optimal seeding rates and nitrogen-phosphorus (NP) fertilizer levels. The study aimed to determine the optimal seeding rate and NP fertilizer levels for maximizing bread wheat productivity in Burie District, Northwestern Ethiopia, during the 2021 and 2022 main cropping seasons. Factorial combinations of four seed rates (100, 120, 150, and 200 kg ha⁻¹) and four NP fertilizer rates (64–46, 87–46, 96–69, and 119–69 kg ha⁻¹ of N-P₂O₅) were examined in a randomized complete block design with three replications. Data on various growth and yield parameters were collected and analyzed using SAS 9.4, with mean separation for significant treatments determined by the least significant difference. The combined analysis revealed significant interactions between seed and NP fertilizer rates, affecting parameters such as days to 90% physiological maturity, plant height, number of effective tillers, spike length, number of kernels per spike, 1000-kernel weight, aboveground dry biomass yield, and grain yield. Days to 50% heading, straw yield, and harvest index were significantly influenced by the main effects of seed and NP fertilizer rates. The highest values for days to 90% maturity, number of effective tillers, and 1000-kernel weight were observed with the lowest seeding rate (100 kg ha⁻¹) combined with the highest NP fertilizer level (119–69 kg ha⁻¹). The highest grain yield (3.70 t ha⁻¹) was achieved with a seeding rate of 150 kg ha⁻¹ and NP fertilizer level of 96–69 kg ha⁻¹, which also yielded the highest net benefit ($1355.60 ha⁻¹) with an acceptable marginal rate of return (8.98%). This treatment combination is recommended for bread wheat production in the Burie district and similar agroecology.

Poa annua L. is one of the most widespread and troublesome weeds of turfgrass. It persists as both an annual and perennial and is adaptable to almost any static maintenance regime, including adaptation to mowing heights and evolution of herbicide resistance. This management guide is intended to provide stakeholders with a summary of new and existing knowledge on integrated Poa annua management. Here we review the basic biology and ecology, as well as practical integrated weed management (IWM) strategies developed for its control.

Due to low cost, farmers often combine foliar insecticide with a foliar fungicide application without assessing insect activity in their soybean [Glycine max (L.) Merr.] field. Therefore, this research was conducted to determine if prophylactic application of foliar insecticide improves soybean yield in Ohio. Objectives were to evaluate the effect of foliar insecticide applied at the R3 and R5 soybean stage on insect defoliation, insect pod and seed damage, and soybean grain yield. The experiment was conducted in 2022 and 2023 for a total of 10 site-years in Ohio. The experimental design was a randomized complete block with four replications of each treatment. Treatments included foliar insecticide applied at the R3 soybean stage (beginning pod), insecticide applied at the R5 soybean stage (beginning seed), and a non-treated control (no insecticide). Soybean leaf area affected by defoliation was evaluated the day of application and 2 weeks after application. At the R8 soybean stage (physiological maturity), soybean plants were collected and evaluated for insect pod damage and seed damage. The foliar insecticide application did not result in any significant change in soybean yield, likely explained by low insect defoliation and low pod damage. Prior to insecticide application, farmers should scout their fields and base decisions on integrated pest management strategies, considering threshold levels.

Interest in seeded bermudagrass cultivars has increased, but there is still a lack of information on management strategies combining nitrogen (N) fertilization and harvest frequency to support producer's decision-making process in a hayfield. In this study, we evaluated how combinations of N fertilization and harvesting management affect total forage accumulation (TFA) and nutritive value in ‘Wrangler’ bermudagrass [Cynodon dactylon (L.) Pers.] for 2 years. Management strategies were combinations of N fertilization (without N, one application, or three applications) and harvesting management (once or three times). Harvesting once or three times did not affect the TFA without N fertilization (H1 and H3) or with one application (H1N1 and H3N1). However, harvesting three times with three N applications (H3N3) presented the greatest TFA (7795 lbs dry matter [DM]/acre) and greater crude protein (CP), net energy gain, total digestible nutrients, and phosphorus (P) concentration, and lesser acid detergent fiber. Consequently, the greatest CP accumulation (CPA) was found in the H3N3 as well. Therefore, associating N fertilization with more frequent harvesting can increase the TFA and CPA, and improve the forage nutritive value, which can significantly affect winter feeding costs.

Some endophytic rhizobacteria, including species producing deaminase enzymes for 1-aminocyclopropane-1-carboxylic acid (ACC) suppressing ethylene production (ACCd), form symbiosis with plant roots to enhance plant growth and stress tolerance. The objectives of this study were to determine growth-promoting effects and effective rates of inoculation with ACCd-producing Paraburkholderia aspalathi (WSF23 and WSF14) on creeping bentgrass (Agrostis stolonifera L.) performance under deficit irrigation in field conditions and effectiveness on post-stress recovery during re-watering. Turf field plots established with ‘L-93’ creeping bentgrass were inoculated with P. aspalathi strains (WSF23 and WSF14) through soil drenching either as a single strain or as a combination of both strains. After inoculation, plots were subjected to drought stress with deficit irrigation to replace 60% of the daily evapotranspiration rate, followed by re-watering for post-stress recovery. Three inoculant rates of 1.0, 1.5, and 2.0 × 10⁷ colony-forming units (CFUs) were evaluated to determine the most effective dosage to apply under field conditions. Inoculation of plants with the consortium of the two strains at 1.5 × 10⁷ CFUs was most effective in enhancing turf quality, percent green cover, normalized difference vegetation index, and dark green color index during drought stress and recovery periods. These results suggest that creeping bentgrass tolerance to drought stress and improved post-stress recovery could benefit from inoculation with P. aspalathi strains under field conditions and also ACC deaminase-producing rhizobacteria could be incorporated into turf management programs to maintain creeping bentgrass during abiotic stress conditions.

Soybean [Glycine max (L.) Merr.] planting date (PD) and maturity group (MG) selection are critical decisions for optimizing crop development and enhancing yield potential. This study examines the interaction effects of PDs and MGs on soybean yield in southern Wisconsin, utilizing a fractional replication experimental design across two growing seasons (2022 and 2023). Five PDs in 2022 and six in 2023 were tested, with 50 soybean cultivars per PD, encompassing MGs ranging from 0.3 to 2.9. Results reveal that optimal soybean yield occurred with early planting, particularly before May 20, with MGs between 1.5 to 2.9 performing best. Delayed planting led to diminished significance in MG selection for yield, but overall yield declined consistently, roughly 20 bu/acre, every 20 days beyond the May 20 PD. Practical implications suggest early planting to maximize sunlight capture and extend the seed fill period, alongside the selection of cultivars within the appropriate MG range. While this study is limited to a single location and 2-year duration, future collaborative efforts across multiple sites could provide a more comprehensive understanding of PD and MG interactions, benefiting soybean cultivation practices in diverse environments. Overall, our findings offer valuable insights for southern Wisconsin soybean farmers seeking to optimize yield and profitability in their operations.