Reduced Corn Yield Research Articles

Transcriptome analysis of maize resistance to Fusarium verticillioides

ABSTRACT Maize (Zea mays) is a crucial crop for both food and economic purposes. Fusarium verticillioides is known to cause ear rot in corn, leading to a reduction in corn yield. Understanding the regulatory network of maize resistance to this ear rot is crucial for identifying key genes associated with disease resistance. The study revealed that inbred line J1259 exhibited resistance to Fusarium verticillioides by increasing the activities of POD and CAT enzymes. Transcriptome analysis at 48 and 96 hours post-infection with Fusarium verticillioides revealed a large number of DEGs involved in plant-pathogen interactions, MAPK signaling pathways-plants and plant hormone signaling were significant up-regulated. Additionally, transcription factors related to hormone signaling, particularly the ARF family involved in auxin regulation, were enriched. These results lay a foundation for further investigations into the mechanisms underlying the disease resistance response of J1259.

Evaluating the yield of surviving plants from early‐season hail damage in corn: A field survey

AbstractEconomic losses due to hailstorms across US corn fields occur every year. Hailstorms result in leaf defoliation, decreasing photosynthetic area and impairing carbon assimilation and crop yield for all corn (Zea mays L.) development stages. However, more attention is often given to stand reductions rather than damage to stems or leaf defoliation. During the 2014 growing season, a natural hail event affected many areas of eastern Nebraska. Twelve affected corn fields were surveyed and included in this study. An injury score scale (1–5) was developed based on various injury and severity levels before the V6 (6‐leaf corn growth stage) (six‐collared leaves). Scores were assigned to affected fields approximately 10–15 days after the hailstorm. At the end of the growing season, ears were harvested, and grain yield per plant was determined. The highest grain yield (p < 0.05) was recorded with plants that were affected but retained a main stem in good condition, albeit defoliation was present (score 1, lowest damage category). In contrast, when the main stem was cut and the plant had poor regrowth (score 3), yields were reduced by approximately 53% compared to plants with an injury score of 1. A significant negative linear relationship (R2 = 0.63, p < 0.01) between injury score and yield was observed (higher injury score from hail events resulted in lower yields). Based on these results, corn yield reduction due to plant injury from hail events before V6 should not be only attributed to stand reductions. Our findings indicate an opportunity to adjust the US evaluation standards for early‐season hail damage events in corn fields.

Effect of cover crop species and termination timing on corn growth and seedling disease

AbstractLater spring termination of fall‐planted cover crops can result in more biomass production, which has the potential to improve environmental benefits. However, later cover crop termination can also have the potential to harm cash crops, such as through increases in corn seedling disease. With the objective of better understanding such potential competing interactions, we evaluated the impact of early and late termination timing of two cover crops—cereal rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth.)—on growth, seedling disease, and grain yield of corn in 2021 and 2022 in Nebraska. The total biomass production varied among treatments. Hairy vetch biomass was lower than cereal rye biomass at both termination times in 2021, but not different from cereal rye terminated early in 2022. Radicle root rot severity, a symptom of corn seedling disease, was not affected by cover crops in 2021. In 2022, however, radicle root rot was most severe in cereal rye terminated late treatments. Hairy vetch did not affect radicle root rot severity, regardless of termination time. Late termination of cereal rye resulted in a reduction in corn yield of 15.3% in 2021 and 76.1% in 2022 compared to no cover crop. Corn (Zea mays L.) grain yield was not affected following hairy vetch at either termination timing. Our results suggest that corn planted following late‐terminated cereal rye can increase the severity of root rot and decrease corn grain yield; however, planting green into hairy vetch can be a successful option to increase biomass without increasing corn seedling disease or decreasing corn yield.

Prediksi Kehilangan Hasil Jagung (Zea mays L.) Akibat Kompetisi Gulma Poaceae di Lahan Kering

This research aims to determine the Poaceae weed species that have a significant effect on corn yield loss in dry land. The research method was descriptive and data collection using survey techniques in 10 sample plots measuring 1 m2 which were placed using random sampling. Observation parameters include the number of species and populations of weeds, the population of corn plants in plot-1 and the dry biomass weight of weeds and corn in plot-1. Quantitative data analysis by calculating relative density, relative frequency and relative dominance values ​​to calculate the importance value index and Summe Diminance Ratio (SDR). The results showed that the diversity, evenness, dominance and abundance of Poaceae weeds in corn plants in dry land was high. So it was found that seven species of weeds were dominant and continued to exist while the corn was growing, namely Paspalum vasginatum Sw., Leersia hexandra Sw., Digitaria longiflora (Retz.) Koel., Digitaria ciliaris (Retz.) Koel., Cynodon dactylon L., Eleusine indica Gaertn., and Panicum repens L. The competitiveness and ability to reduce corn yields of the weeds Paspalum vasginatum, Leersia hexandra and Digitaria longiflora are higher than other weeds, so that corn yield losses due to competition reach 16.45%, 7.48% and 4.40%. The weeds Brachiaria reptans, Axonopus compressus and Echinochloa colonum do not need to be controlled in corn after the plants are 45 DAT, because their competitiveness and ability to eliminate crop yields is very low.

Preplant Herbicide Programs for the Control of Multiple-Herbicide-Resistant Waterhemp in No-Till Corn

Multiple-herbicide-resistant (MHR) waterhemp has been confirmed in 18 Ontario counties. A total of four experiments were conducted in commercial fields with MHR waterhemp in 2020 and 2021 to evaluate preplant (PP) herbicide tank mixtures for control of MHR waterhemp in no-till corn. There was minimal visible corn injury from the herbicide treatments evaluated. At 2 WAA, all herbicide tank mixtures provided greater than 90% control of MHR waterhemp except for pyroxasulfone/carfentrazone + atrazine which controlled MHR waterhemp 85%. At 12 WAA, S-metolachlor/mesotrione/atrazine, S-metolachlor/mesotrione/bicyclopyrone/atrazine, and diflufenican + atrazine + flufenacet controlled MHR waterhemp 86, 91, and 98%, respectively; all other herbicide tank mixtures provided 65 to 83% control. At 8 WAA, S-metolachlor/mesotrione/bicyclopyrone/atrazine and diflufenican + atrazine + flufenacet reduced MHR waterhemp density 97 and 100%, respectively similar to the weed-free control; all other herbicide tank mixtures reduced MHR waterhemp density 64 to 96%. At 8 WAA, S-saflufenacil/dimethenamid-P + mesotrione, S-metolachlor/mesotrione/atrazine, tembotrione + dicamba + flufenacet, metolachlor/mesotrione/bicyclopyrone/atrazine, and diflufenican + atrazine + flufenacet reduced MHR waterhemp biomass 96, 97, 98, 98, and 100%, respectively; all other herbicide tank mixtures reduced MHR waterhemp biomass 72 to 93%. MHR waterhemp interference reduced corn yield 80% in this study. All herbicide tank mixtures resulted in corn yield that was similar to the weed-free control. Among the herbicide tank mixtures evaluated S-metolachlor/mesotrione/bicyclopyrone/atrazine and diflufenican + atrazine + flufenacet provided the greatest control of MHR waterhemp in no-till corn.

Cover crops and irrigation impacts on corn production and economic returns

Increases in irrigated crop acreage and frequent droughts during the growing season have caused continual groundwater decline of the Mississippi River Valley Alluvial Aquifer in the Mississippi Delta region. A field experiment was conducted from 2019 to 2021 to determine if combinations of irrigation scheduling thresholds and cover crops (CCs) could improve corn (Zea mays L.) production, water productivity (WP), irrigation water use efficiency (IWUE), and net returns. The irrigation thresholds used for irrigation scheduling were a wet threshold (−40 kPa), a dry threshold (−90 kPa), and no irrigation. The CC treatments were cereal rye (Secale cereale L.), hairy vetch (Vicia villosa R.), wheat (Triticum aestivum L.)-radish (Raphanus sativus L.)-turnip (Brassica rapa L.) mix, and no cover crop. In 2020, CCs reduced corn yield by 9–26% compared to no cover crop. In 2021, wet irrigation threshold treatments had 8% and 9% higher corn yield than no irrigation and dry irrigation threshold treatments, respectively. No irrigation treatments showed higher WP than dry and wet irrigation thresholds, while hairy vetch had higher in WP among CC treatments in year two of this study. Hairy vetch under the dry irrigation threshold had higher IWUE than all other treatments. The no-CC treatments generated $167, $340, and $58 ha−1 more under the wet, dry, and no irrigation treatments, respectively, when averaged over both years. Water conservation was affected by CC selection and irrigation management.

What Are the Most Efficacious Herbicides Applied Preplant for Control of Multiple-Herbicide-Resistant Canada Fleabane in Corn?

New weed management strategies are needed to effectively control multiple-herbicide-resistant (MHR) Canada fleabane in corn. Five experiments were established in growers’ corn fields with confirmed MHR Canada fleabane to determine the efficacy of various herbicides applied preplant (PP). In 2021 environments, glyphosate + isoxaflutole + atrazine, glyphosate + isoxaflutole/diflufenican + atrazine, glyphosate + S-metolachlor/atrazine/mesotrione/bicyclopyrone, glyphosate + mesotrione + atrazine, glyphosate/dicamba + isoxaflutole/diflufenican, glyphosate/dicamba + isoxaflutole/diflufenican + atrazine, and glyphosate + saflufenacil/dimethenamid-p provided excellent control (90-100%) of MHR Canada fleabane but glyphosate + S-metolachlor/mesotrione/bicyclopyrone and glyphosate + S-metolachlor/atrazine/mesotrione controlled MHR Canada fleabane 77-84% and 87-96%, respectively at 4, 8, and 12 weeks after application (WAA). Herbicide tankmixes evaluated reduced MHR Canada fleabane density and biomass 91-100%. In 2022 environments, all glyphosate tankmixes evaluated provided 97-100% control, 99-100% density reduction, and 100% biomass reduction of MHR Canada fleabane in corn. In 2021 and 2022 environments MHR Canada fleabane interference reduced corn yield 41 and 32%, respectively; reduced MHR Canada fleabane interference with all herbicide treatments resulted in corn yield similar with the weed-free control. Results of this study indicate that glyphosate + isoxaflutole + atrazine, glyphosate + isoxaflutole/diflufenican + atrazine, glyphosate + S-metolachlor/atrazine/mesotrione/bicyclopyrone, glyphosate + mesotrione + atrazine, glyphosate/dicamba + isoxaflutole/diflufenican, glyphosate/dicamba + isoxaflutole/diflufenican + atrazine, and glyphosate + saflufenacil/dimethenamid-p provide excellent and consistent control of MHR Canada fleabane. However, glyphosate + S-metolachlor/atrazine/mesotrione and glyphosate + S-metolachlor/mesotrione/bicyclopyrone do not provide consistent control of MHR Canada fleabane in corn.

Landscape position and cover crops affects crop yields in a terrace-tiled field

Cover crops (CC) provide soil ecosystem benefits including reduced soil erosion, improved soil health, and nutrient cycling. However, the effect of CCs on rotational commodity crop grain yields and nutrient uptake may vary at different landscape positions and under different soil moisture dynamics. The objectives of this study were to determine the influence of CCs in a terraced field on soil moisture at crop emergence and reproductive stages of corn (Zea mays L) and soybean (Glycine max L. Merr.) development, and evaluate CCmix (wheat (Triticum aestivum L.), radish (Raphanus raphanistrum subsp. Sativus), and turnip (Brassica rapa subsp. Rapa)) and cereal rye (Secale cereale L.) effect on corn and soybean grain yield and plant nutrient concentration, respectively. A randomized complete block design with two treatments including cover crop (CC) and no cover crop (no CC) and three replications was used. In this 4-year study, cereal rye produced 1.0–1.6 Mg ha−1 higher aboveground biomass compared to the CCmix species. Nutrient uptake in the CCmix biomass was greater than cereal rye. Soybean yield following cereal rye termination was not influenced by the CC treatment (P = 0.3229). Dry climatic conditions during the soybean growing period and landscape positions influenced grain yield and nutrient uptake. Average soybean yield at different landscape positions was ranked as shoulder (4.8 Mg ha−1) > backslope (4.4 Mg ha−1) > footslope (3.9 Mg ha−1) > channel (3.6 Mg ha−1). In 2021, corn yield was reduced 29% following the CCmix compared to no CC control, indicating a yield penalty when corn was preceded with the CCmix species. In this study, higher CC biomass production exacerbated soil wetness in a wet year (2021), resulting in uneven corn germination and excess soil water stress on plant growth. Increased soil wetness at channel and footslope positions in 2019 and 2021 reduced corn yield 45–70%. This study suggests that CCs in terraced fields can have a neutral or negative effect on the following commodity crop yield depending on the weather conditions.

What Are the Most Efficacious Herbicides Applied Postemergence for Control of Multiple-Herbicide-Resistant Canada Fleabane [Conyza canadensis (L.) Cronq.] in Corn?

Multiple-herbicide-resistant (MHR) Canada fleabane [Conyza canadensis (L.) Cronq.] control has become a major concern for corn producers in Ontario. Postemergence (POST) herbicides are critical for the control of emerged MHR Canada fleabane in corn. A study that consisted of five field experiments was conducted in southwestern Ontario in fields with confirmed MHR Canada fleabane to evaluate various herbicide mixtures applied POST for the control of MHR Canada fleabane in corn. Glyphosate + 2,4-D amine, glyphosate/2,4-D choline, glyphosate + clopyralid, glyphosate + S-metolachlor/mesotrione/bicyclopyrone, glyphosate + tolpyralate + atrazine, glyphosate + dicamba, glyphosate + dicamba/atrazine, glyphosate + S-metolachlor/mesotrione/ atrazine, glyphosate + mesotrione + atrazine, glyphosate + bromoxynil + atrazine, glyphosate + S-metolachlor/ mesotrione/bicyclopyrone/atrazine, glyphosate/S-metolachlor/mesotrione + atrazine, glyphosate/dicamba + tembotrione, glyphosate + tembotrione + bromoxynil, glyphosate/dicamba + tembotrione + atrazine, and glyphosate + tembotrione + atrazine applied POST provided 63-99% control, 77-100% density reduction, and 88-100% shoot biomass reduction of MHR Canada fleabane in corn. MHR Canada fleabane interference reduced corn yield up to 58%; reduced MHR Canada fleabane interference with all herbicide treatments resulted in corn yield similar to the weed-free control. Results of this study indicate that among the herbicide mixtures evaluated glyphosate + mesotrione + atrazine, glyphosate + bromoxynil + atrazine, glyphosate + S-metolachlor/ mesotrione/bicyclopyrone/atrazine, glyphosate/S-metolachlor/mesotrione + atrazine, glyphosate/dicamba + tembotrione, glyphosate + tembotrione + bromoxynil, glyphosate/dicamba + tembotrione + atrazine, and glyphosate + tembotrione + atrazine applied POST provided the most consistent control of MHR Canada fleabane in corn.

Yield tradeoffs of early corn harvest to enhance pennycress establishment

AbstractOilseed pennycress (Thlaspi arvense L.) establishment following grain corn (Zea mays L.) harvest in northern latitudes is challenging because of the short duration between corn harvest and soil freeze. The use of shorter season corn hybrids for a region may partly solve this challenge, but tradeoffs in reduced corn yield may be a concern. This study evaluated corn relative maturity (CRM) hybrids on pennycress establishment, seed and oil yields, and corn grain yield tradeoffs. The CRM hybrids ranged from 76‐ to 95‐day for northern sites (Morris and Rosemount, MN), and from 95‐ to 113‐day for the southern sites (Custar, OH, and Lexington, IL). The checks were full‐season corn (113‐ and 95‐day corn for the southern and the northern sites, respectively) harvested for silage. Pennycress plant density, green cover, and yield were generally greater when pennycress was seeded following silage corn due to early seeding and reduced corn stover. Pennycress seed yields ranged from 388 to 778, 641 to 834, 362 to 784, and 834 to 2038 kg ha−1 at Custar, Lexington, Morris, and Rosemount, respectively. The results showed that growing 86‐ and 105‐day grain corn in the northern and southern sites, respectively, facilitated timely pennycress establishment with little or no corn grain yield loss compared with full‐season hybrids. Developing pennycress varieties better suited for emergence under high corn stover or employing stover management practices to increase autumn emergence is suggested. Additionally, an economic analysis of the entire cropping sequence (corn–pennycress–soybean) is needed.

Tradeoffs when interseeding cover crops into corn across the Chesapeake Bay watershed

CONTEXTIn annual cropping systems at high latitudes, an early onset of winter limits the establishment of cover crops in fall and ultimately the ecosystem services they provide such as nitrogen (N) leaching reduction. Interseeding cover crops into a standing cash crop can improve establishment before winter, but its practice is limited in both scope and scale. OBJECTIVETo identify tradeoffs and establish regional patterns of interseeding success in the environmentally sensitive Chesapeake Bay Watershed of North America, we used the agroecosystem model Cycles to compare in silico systems in which cover crops were either interseeded into a standing crop of corn (Zea mays L.) or conventionally seeded after corn harvest. METHODSIn each of the 153 counties contained in the Chesapeake Bay Watershed, a representative field was simulated and either seeded with ryegrass (Lolium perenne L.), a blend of legumes, or a mix of legumes and ryegrass in a continuous corn sequence. The simulated corn yield, cover crop biomass production, N leaching reduction, and total N losses were compared between the cover crop scenarios and a monoculture corn control. RESULTS AND CONCLUSIONSSimulations showed that conventionally seeded cover crops did not affect corn yields of the following year. However, when interseeded, the drag on corn yield in the same year averaged 6% per Mg of fall cover crop biomass. The corn yield reduction notwithstanding, interseeding reduced N leaching by 10% for legumes, 25% for the mix, and 50% for solo ryegrass compared to the no cover-crop control. There are other tradeoffs, such as an offset of N fertilizer inputs from N2 fixation when using legumes despite the less effective nutrient capture. Regardless of the cover crop type, interseeding up to latitude 41° N tends to be competitive with the cash crop, but north of that threshold (or west into higher elevations) the mitigation of N leaching when interseeding seems to outweigh agronomic costs. SIGNIFICANCEThis study provides useful insight into watershed-scale agronomic and environmental processes without the constraints of establishing large-scale networks of field trials. Given these analyses, future field research in areas suitable for interseeding can focus on establishing legume cover crops in high-yielding fields with low residual mineral N, grass cover crops in manured or low-yielding fields with residual mineral N, and a mixture of both when N supply is uncertain and preventive management is needed.

Response patterns of simulated corn yield and soil nitrous oxide emission to precipitation change

BackgroundPrecipitation plays an important role in crop production and soil greenhouse gas emissions. However, how crop yield and soil nitrous oxide (N2O) emission respond to precipitation change, particularly with different background precipitations (dry, normal, and wet years), has not been well investigated. In this study, we examined the impacts of precipitation changes on corn yield and soil N2O emission using a long-term (1981–2020, 40 years) climate dataset as well as seven manipulated precipitation treatments with different background precipitations using the DeNitrification-DeComposition (DNDC) model.ResultsResults showed large variations of corn yield and precipitation but small variation of soil N2O emission among 40 years. Both corn yield and soil N2O emission showed near linear relationships with precipitation based on the long-term precipitation data, but with different response patters of corn yield and soil N2O emission to precipitation manipulations. Corn yield showed a positive linear response to precipitation manipulations in the dry year, but no response to increases in precipitation in the normal year, and a trend of decrease in the wet year. The extreme drought treatments reduced corn yield sharply in both normal and wet years. In contrast, soil N2O emission mostly responded linearly to precipitation manipulations. Decreases in precipitation in the dry year reduced more soil N2O emission than those in the normal and wet years, while increases in precipitation increased more soil N2O emission in the normal and wet years than in the dry year.ConclusionsThis study revealed different response patterns of corn yield and soil N2O emission to precipitation and highlights that mitigation strategy for soil N2O emission reduction should consider different background climate conditions.

Annual Ryegrass Control in Corn With Glyphosate plus Residual Herbicides Applied Preplant in the Spring

Glyphosate needs to be partnered with other herbicides that have residual biological activity on ryegrass (Lolium multiflorum Lam.) to improve the efficacy and consistency of annual ryegrass control in corn. Five field experiments were conducted from 2019 to 2021 near Exeter, Ontario to evaluate various glyphosate tank mixes applied preplant (PP) in the spring in corn for the control of annual ryegrass seeded as a cover crop in the fall of the previous year (2018 to 2020). At 1 week after application (WAA), all glyphosate tank mixes evaluated provided minimal annual ryegrass control (14-28%). At 2 WAA, the addition of dimethenamid-p/saflufenacil to glyphosate improved annual ryegrass control from 55% to 68%; there was no improvement in annual ryegrass control with the other 14 tank mixes evaluated. At 3 WAA, the addition of dimethenamid-p/saflufenacil and mesotrione + rimsulfuron to glyphosate controlled annual ryegrass 91 and 90%, respectively. At 4 WAA, the addition of dimethenamid-p, dimethenamid-p/saflufenacil, mesotrione + rimsulfuron, S-metholachlor, or bicyclopyrone/mesotrione/S-metolachlor to glyphosate improved annual ryegrass control 7, 7, 10, 8, and 6%, respectively. At 6 WAA, the addition of pyroxasulfone, pyroxasulfone + atrazine, dimethenamid-p, dimethenamid-p/saflufenacil, mesotrione + rimsulfuron, S-metholachlor, atrazine/S-metolachlor, or bicyclopyrone/mesotrione/S-metolachlor to glyphosate improved annual ryegrass control 10, 9, 12, 10, 17, 13, 10, and 12%, respectively but the addition of all other herbicides to glyphosate did not improve annual ryegrass control. Density and biomass reductions of annual ryegrass with glyphosate tank mix evaluated generally followed a similar trend as the visible control. Annual ryegrass interference reduced corn yield by up to 83% compared to the non-treated control. The addition of a residual herbicide to glyphosate did not result in an improvement in the seed yield of corn. Among the glyphosate tank mixes evaluated glyphosate + mesotrione + rimsulfuron provided the most consistent control of annual ryegrass in corn.

Evaluating a newer three component herbicide Fulltime, MD for corn (Zea mays) in the central agro-climatic zone of Krasnodar Krai, Russia

Among the factors that reduce corn yield, the main one is the infestation of crops. Thus, field experiments were carried out in 2019 and 2020 on the basis of the Federal State Budgetary Scientific Institution "Federal Research Center of Biological Plant Protection" (Krasnodar). The aim of the research was to study the effect of the herbicide Fultime, MD (75 g/L mesotrione + 37.5 g/L nicosulfuron + 17.5 g/L picloram) in corn crops. The experiments were laid out in the form of randomized blocks on plots of 25 m2 in quadruple repetition. In the variants with the use of the herbicide Fultime, MD at the rates of 1.0 and 2.0 L/ha, 82-100% herbicidal effect was noted against dicotyledonous and cereal weeds without a negative effect on corn and a significant preserved grain yield (83.8 and 91.9 %) in comparison with the control (without herbicides).

Evaluating a newer three component herbicide Fulltime, MD for corn (Zea mays) in the central agro-climatic zone of Krasnodar Krai, Russia

Among the factors that reduce corn yield, the main one is the infestation of crops. Thus, field experiments were carried out in 2019 and 2020 on the basis of the Federal State Budgetary Scientific Institution "Federal Research Center of Biological Plant Protection" (Krasnodar). The aim of the research was to study the effect of the herbicide Fultime, MD (75 g/L mesotrione + 37.5 g/L nicosulfuron + 17.5 g/L picloram) in corn crops. The experiments were laid out in the form of randomized blocks on plots of 25 m2 in quadruple repetition. In the variants with the use of the herbicide Fultime, MD at the rates of 1.0 and 2.0 L/ha, 82-100% herbicidal effect was noted against dicotyledonous and cereal weeds without a negative effect on corn and a significant preserved grain yield (83.8 and 91.9 %) in comparison with the control (without herbicides).

Evaluating the role of gamma irradiation to ameliorate salt stress in corn

Purpose Salt stress is a significant issue in corn cultivation leading to corn yield reduction, especially in the arid and semi-arid regions. Nuclear technologies, along with other standard methods, can be used as an efficient method for mitigating salt stress effects on plants. Materials and methods In this research, gamma irradiation (GI) was studied on seeds in the salt stress amelioration of corn in laboratory and field conditions. A total of five doses of gamma rays (25, 50, 100, 150 and 200 Gy) were applied to corn seeds (SC.703) at the laboratory under saline and control conditions. The best gamma-ray treatment (25 Gy) was selected for studying corn under salt stress in the field condition. Results The length of the radicle, seminal roots and shoot, dry weight of radicle, and seminal roots were affected by salt stress (p <.001). However, GI affected only the radicle and seminal root length (p < .001). The radicle length was decreased as much as 3, 11, 17, 25, and 27% in 25, 50, 100, 150 and 200 Gy of GI, respectively. In addition, the seminal root length was decreased in all GI treatments except 25 Gy (p < .05). Plants derived from seeds exposed to GI (25 Gy) had a higher chlorophyll content of 1, 17, and 29% at V3 (third leaf stage), R1 (silk stage, p < .001), and R4 (dough stage, p < .001), respectively. In GI treatment, the soluble carbohydrate content was significantly higher (p < .001) at all three measurement stages and the soluble protein was significantly higher (p < .001) only at the R4 stage. Moreover, proline content was higher in GI (25 Gy) at V3 (58%, p < .05) and R1 (98%, p < .001) treatment stages. Conclusion Since plants from gamma-irradiated seeds had a greater plant weight and their economic traits (cob and grain weight) were higher compared to control plants under salt stress conditions, it can be concluded that a low dose of GI may ameliorate the effect of salt stress on the corn plants.

Biodegradable and biobased mulch residues had limited impacts on soil properties but reduced yield of the following crop in a low fertility soil

AbstractBiodegradable and biobased mulch films and fabrics (BDMs) are potentially sustainable alternatives to polyethylene plastic mulch film (PE) in vegetable production because BDMs can be incorporated into the soil by tillage at the end of the growing season for decomposition. However, grower adoption has been limited in part by concerns about slow degradation rates and possible adverse effects on soil health and productivity. The objective of this study was to measure the effects of soil incorporated residues from two BDMs and compost on soil chemical and physical properties and vegetable crop yield across two diverse locations [Lincoln (LNK) and Scottsbluff (SBF), NE, USA] during a 2-yr study. The BDMs, including a polylactic acid biofabric with embedded wood particles (PLA; 1.14 mm thick and 298 g m−2), and a starch-polyester bioplastic mulch film (STP; 0.015 mm thick and 20 g m−2), were applied in May 2017 for vegetable production. Mulches were incorporated in soil by tillage in September 2017 in half of the experimental plots and removed in the other half as a control. Compost was applied in fall 2017 and 2018 at rates between 42 and 60 Mg ha−1 to establish high and low (no compost) fertility soil environments within each location. Sweet corn (Zea mays) was grown in 2018 and cabbage (Brassica oleraceae) in 2019, and yield data were collected. The soil was sampled at ~6 month intervals for two years. The BDM residues had little effect on soil pH, organic matter or physical properties, but the incorporation of PLA in the soil at SBF reduced soil nitrate 6 months after the incorporation of residues. Nitrogen immobilization likely contributed to the 16% ± 5% reduction in sweet corn yield observed at SBF in plots without compost where BDM residues were incorporated compared to removed. No additional yield differences were detected in sweet corn (2018) or cabbage (2019) across locations or treatments, which suggests that BDM residues are less likely to immobilize nitrogen and reduce yield in high fertility soil environments. Given the potential environmental benefits of BDMs as an alternative to PE, future research should seek to mitigate the negative effects of BDM residues on crop yield, particularly in lower fertility soils.

Metsulfuron-methyl soil persistence influence in corn grown in succession

The metsulfuron-methyl is a soil persistent herbicide and can affect the development and yield of sensitive crops grown in succession. The objective this study was evaluate the effect of the application of metsulfuron-methyl at different intervals before sowing on corn development and yield and determine a safe period between the application of the metsulfuron-methyl and corn sowing. The assay was conducted in the 2017/18 and 2018/19 seasons. The experimental design was of randomized blocks, with thirteen treatments and four replicates. The treatments were arranged in factorial scheme (2 × 6) + 1. The first factor consisted in doses of metsulfuron-methyl (1.98 and 3.96 g ha-1). The second factor in intervals between the application of the herbicide and corn sowing (0, 15, 30, 45, 60, and 75 days), plus a control with no herbicide application. The phytotoxicity, yield, and yield components of corn were assessed. The highest phytotoxicity occurred at 3.96 g ha-1, when the herbicide was applied on the day of sowing. Metsulfuron-methyl caused phytotoxicity and reduced corn yield. The safe interval between metsulfuron-methyl application and corn sowing was 15 and 30 days for the doses of 1.98 and 3.96 g ha-1, respectively.

Soil Moisture or ET-Based Smart Irrigation Scheduling: A Comparison for Sweet Corn with Sap Flow Measurements

Smart irrigation is one application of digital agriculture that can be used to achieve improved crop yields while saving water and energy. Many variations of smart irrigation can be applied, but there is no consensus among the scientific community as to which method is the best practice. The objective of this research was to evaluate two smart irrigation methods: a soil moisture–based method using sensors and an evapotranspiration- (ET-) based technique. The selected crop was sweet corn. Growth variables (biomass, yield, harvest index, and water productivity) were compared for each of the two methods. Three irrigation regimes were applied for each method: 60%, 90%, and 120% of crop evapotranspiration (ETc) for the ET-based method, and 25%, 30%, and 35% of the total soil moisture for the soil moisture–based method. Corn sap flow was measured in response to the three treatments in the soil moisture–based experiment to measure transpiration. The results showed that the ET-based method is easier to implement with less infrastructure, and it can result in similar yields compared to the soil moisture–based method. Although the fresh yield was 16% higher using the soil moisture–based method, grain yield can be sustained with the ET-based method using 8% less water. Selection of an appropriate irrigation scheduling method should be based on marketable yield: keeping the soil water content near field capacity will result in a higher fresh yield but will not translate into more dry matter. If grain yield is the target, the ET-based method is less expensive and more farmer friendly, but care should be taken to properly estimate irrigation losses to avoid underirrigation. An evaporative stress index (determined using sap flow measurements) of 70% will cause a 22% reduction in fresh sweet corn yield but only a 7% reduction in grain yield. Transpiration peaked when the soil moisture was above 85% of the available water (i.e., at 38% in the calcareous clay soil of the experiment).

The stink bug Dichelops furcatus: a new pest of corn that emerges from soybean stubble.

Over the last decades, Argentine and Brazilian farmers have adopted no-tillage cultivation systems and multiple cropping, which have decreased the abundance of traditional pests, such as Nezara viridula, and favored the development of some stink bugs of secondary importance, like Dichelops furcatus, D. melacanthus and Euschistus heros. No-till farming leaves the soil undisturbed, to mitigate erosion, and sufficient crop residue on the field, which is used by D. furcatus as a shelter under unfavorable conditions, and as a shelter against insecticides. Moreover, implementing multiple cropping systems increases crop rotation from soybean to corn, and places overwintering adults of D. furcatus in contact with corn seedlings in spring. Attacks of this stink bug species produce deformation and abortion of corn seedlings, resulting in up to 50% corn yield reduction. The increasing abundance of D. furcatus intensifies the damage on developing pods and seeds of soybean, becoming a primary pest of soybean, and a new pest of corn. Here we summarize the current knowledge about D. furcatus, its biology, life cycle, and geographical distribution pattern in South America. Additionally, we describe the general causes and consequences of D. furcatus as a new pest of corn that emerges from crop stubble. Then, we provide an overview of the chemical control, natural enemies, and possible agronomical practices to improve sustainable crop production methods to control this pest. © 2022 Society of Chemical Industry.