Crop, Forage and Turfgrass Management最新文献

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.

Cover crops are an effective way to reduce soil erosion and promote soil health. However, in North Dakota and other northern climates where corn (Zea mays L.) is an important commodity crop, killing frosts generally occur before harvest, leaving little opportunity for cover crop planting. By interseeding cover crops into corn during the growing season, the cover crops are given a longer period to establish. The purpose of this study was to identify the impact cover crops interseeded into wide-row (60-inch) corn have on soil water content and corn productivity. Two experimental sites were established in 2020 near Leonard and Rutland, ND. Both sites were organized into randomized complete block designs, with three cover crop treatments in Leonard (n = 9) and four cover crop treatments in Rutland (n = 16). Cover crops were no-till drilled into the corn at the V4 growth stage. The cover crop treatments were diverse mixes developed to either provide pollinator habitat, overwinter, or winter-kill. Throughout the growing season, soil gravimetric water content and cover crop biomass was monitored. At the end of the growing season, dry cover crop biomass ranged from 189 to 1445 lb ac⁻¹. The presence and type of interseeded cover crops did not have a statistically significant effect on soil water content or corn yield. It is suspected the above average precipitation during the month of July led to adequate amounts of soil water for the entirety of the cover crop growing season, limiting the difference between treatments.

Improved management strategies are needed to increase corn (Zea mays L.) production. This study aimed to determine suitable cultural practices for improved corn production in Mississippi. Two experiments were setup side-by-side (addition/deletion) at Verona and Stoneville, MS, from 2020 to 2022. A randomized complete block design was implemented that included two row configurations (single- and twin-row), two plant populations (32,000 and 40,000 plants acre⁻¹), and six combinations of nutrients with or without a fungicide. Nutrients including nitrogen (N) 210 and 280 lb acre⁻¹, phosphorus (P) 40 lb acre⁻¹, potassium (K) 100 lb acre⁻¹, elemental sulfur (S) 20 lb acre⁻¹, zinc (Zn) 10 lb acre⁻¹, and fungicide at 3.72 oz acre⁻¹ were applied. In the addition trial, nutrients plus fungicide were added incrementally, whereas in the deletion trial these were withheld in a stepwise manner. Among the tested factors, row configuration impacts were the most consistent among all site-years; specifically, twin-rows resulted in higher yield compared to single-row. Additionally, higher plant population under irrigated conditions (Stoneville) resulted in greater yield compared to rainfed conditions (Verona). Higher rate of N and fungicide application affected grain yield positively, but these agronomic benefits were not economically feasible. This study determined that application of different nutrients can enhance the yield to a limited extent, and farmers should consider the economic investment of fertilizer and fungicides. Moreover, producers should balance yield and profit by taking soil testing and fertilizer prices into consideration.

Global demand for corn (Zea mays L.) is increasing, and it remains one of the most consumed crops by both humans and animals due to its high calorie content. However, corn grain quality research is sparse and often focused only on a few selected influencing factors. Therefore, two side-by-side studies (Addition and Deletion) were conducted in 2020 and 2021 in Mississippi to assess the grain composition including protein, starch, oil, and moisture of corn under several management practices. A randomized complete block design was implemented in both experiments involving a complete factorial of three factors including two plant populations (32,000 and 40,000 seed acre⁻¹), two-row configurations (single and twin), and six combinations of nutrients plus fungicide application (NF). The trials differed based on the manner of NF applications. In the trial termed Addition, all NF treatments were added incrementally, whereas in the Deletion trial they were withheld in a stepwise manner. Conditional inference tree analysis was conducted to examine interaction effects among the three factors over 3 site-years. Corn protein content ranged between 8.2% and 9.8% across all years and locations. All three factors and certain interactions significantly influenced both protein and starch content. Specifically, single row planting, 40,000 seeds acre⁻¹, and higher rates of N resulted in higher protein content. Contrarily, the starch content was positively influenced by twin row, 32,000 seeds acre⁻¹ and only N application. Single row configuration resulted in higher oil than twin rows. This study determined that different management factors have the potential to positively influence protein, starch, and oil. These management strategies could extend farmers profitability and provide superior products for industrial purposes with additional implications for livestock feed supplements.

In Florida, multiple counties restrict the application of N to turfgrass and landscapes during the summer rainy season. These summer fertilizer blackout periods could impact turfgrass quality and the functionality of warm-season turfgrass species. A 2-year study was conducted at the University of Florida's Fort Lauderdale Research and Education Center (FLREC) and West Florida Research and Education Center (WFREC) to assess turfgrass performance of ‘Floratam’ and ‘Classic’ St. Augustinegrass [Stenotaphrum secundatum (Walter) Kuntze] as well as ‘Empire’ and ‘Palisades’ zoysiagrass (Zoysia japonica Steud.), respectively, receiving no N fertilization during summer blackout period using eight fertilization programs compared to an unfertilized control. Visual quality, normalized difference vegetation index, percentage green cover, and dark green color index were assessed biweekly. Roots were collected before and after the fertilizer blackout period to determine root dry weight. While no differences were detected in St. Augustinegrass at the FLREC and zoysiagrass at the WFREC, all fertilized treatments except urea reached and maintained an acceptable turfgrass quality (≥6) throughout the blackout period, suggesting that urea by itself was not sufficient to support an optimal turfgrass performance during a fertilizer blackout period. The addition of P to nutrition programs did not influence turfgrass quality. Results indicate that N source is the most important factor to sustain turfgrass quality year-round in Florida.