Modern Corn Research Articles

Profile of the southern corn billbug, Sphenophorus callosus Oliver, an important pest of corn in eastern North Carolina

Abstract Southern corn billbug Sphenophorus callosus Oliver, was a historically widespread and damaging pest throughout the southeastern United States. However, it only persists as a major problem in poorly drained corn production areas in eastern North Carolina. Unfortunately, little replicated research has been conducted on this insect in corn since the 1980s. The purpose of this profile is to provide a current, comprehensive resource on the biology and ecology of this pest relative to corn, as well as to provide a description of sampling and management methods. This is a univoltine insect with a narrow host range. The only known cultivated host it will reproduce on is corn, Zea mays L., and yellow nutsedge, Cyperus esculentus L. Injury and damage to corn can be caused by adult feeding on seedlings, or by larval development in the crown. The most effective management tactics for southern corn billbug are cultural management tactics, including crop rotation, tillage, proper fertility, drainage, and effective weed control. Neonicotinoid seed treatments are the most important management tactic for this pest, but their efficacy is declining. Hence, this pest may become more problematic across the southeastern United States. A significant portion of the biological research on this insect needs to be revisited within the context of modern corn production practices. Furthermore, more work should be done to understand the mechanisms for effective cultural management tactics. Finally, novel methods of management should be explored for this insect to expand the range of available management tactics.

Ecological problems of modern corn protection systems against harmful organisms in Ukraine: review

Ecological problems of modern corn protection systems against harmful organisms in Ukraine: review

Recalibrating the Pennsylvania pre‐sidedress soil nitrate test recommendations for modern corn production

AbstractThe pre‐sidedress soil nitrate test (PSNT) was developed over 30 years ago to determine sidedress nitrogen (N) fertilizer recommendations for corn (Zea mays L.). Since the original PSNT calibrations were developed, changes in production practices such as no‐till and cover cropping and increases in corn yields and N use efficiency could affect the accuracy of PSNT recommendations. To update the PSNT recommendations in Pennsylvania and demonstrate the test's efficacy, we compiled a dataset of 32 calibration sites and 13 demonstration sites where the PSNT was conducted, and the economically optimum N rate (EONR) for corn was determined from an N fertilizer yield response curve. We recalibrated the PSNT recommendation algorithm and compared its accuracy to the original calibration. The new calibration resulted in a single long‐term manure history factor that interacted with the PSNT result to adjust the sidedress N recommendation (−5.7 kg N ha−1 [mg NO3‐N kg−1]−1). The new calibration also included a term for a mixed species cover crop, which increased the sidedress N recommendation 56.2 kg N ha−1. Finally, the coefficient that scales the N fertilizer recommendation based on yield goal decreased by 29% from the original calibration to 12.9 kg N Mg−1 grain. The new algorithm for predicting EONR reduced the error of the sidedress N recommendation by one‐half compared to the original calibration. The new PSNT calibration will allow users to accurately determine sidedress N recommendations in sites with a long‐term manure history and underscores the importance of updating soil fertility recommendation algorithms with modern data.

Predicting corn tiller development in restrictive environments can be achieved to enhance defensive management decision tools for producers.

While globally appreciated for reliable, intensification-friendly phenotypes, modern corn (Zea mays L.) genotypes retain crop plasticity potential. For example, weather and heterogeneous field conditions can overcome phenotype uniformity and facilitate tiller expression. Such plasticity may be of interest in restrictive or otherwise variable environments around the world, where corn production is steadily expanding. No substantial effort has been made in available literature to predict tiller development in field scenarios, which could provide insight on corn plasticity capabilities and drivers. Therefore, the objectives of this investigation are as follows: 1) identify environment, management, or combinations of these factors key to accurately predict tiller density dynamics in corn; and 2) test outof-season prediction accuracy for identified factors. Replicated field trials were conducted in 17 diverse site-years in Kansas (United States) during the 2019, 2020, and 2021 seasons. Two modern corn genotypes were evaluated with target plant densities of 25000, 42000, and 60000 plants ha -1. Environmental, phenological, and morphological data were recorded and evaluated with generalized additive models. Plant density interactions with cumulative growing degree days, photothermal quotient, mean minimum and maximum daily temperatures, cumulative vapor pressure deficit, soil nitrate, and soil phosphorus were identified as important predictive factors of tiller density. Many of these factors had stark non-limiting thresholds. Factors impacting growth rates and photosynthesis (specifically vapor pressure deficit and maximum temperatures) were most sensitive to changes in plant density. Out-of-season prediction errors were seasonally variable, highlighting model limitations due to training datasets. This study demonstrates that tillering is a predictable plasticity mechanism in corn, and therefore could be incorporated into decision tools for restrictive growing regions. While useful for diagnostics, these models are limited in forecast utility and should be coupled with appropriate decision theory and risk assessments for producers in climatically and socioeconomically vulnerable environments.

Corn yield components can be stabilized via tillering in sub-optimal plant densities.

Crop plasticity is fundamental to sustainability discussions in production agriculture. Modern corn (Zea mays L.) genetics can compensate yield determinants to a small degree, but plasticity mechanisms have been masked by breeder selection and plant density management preferences. While tillers are a well-known source of plasticity in cereal crops, the functional trade-offs of tiller expression to the hierarchical yield formation process in corn are unknown. This investigation aimed to further dissect the consequences of tiller expression on corn yield component determination and plasticity in a range of environments from two plant fraction perspectives - i) main stalks only, considering potential functional trade-offs due to tiller expression; and ii) comprehensive (main stalk plus tillers). This multi-seasonal study considered a dataset of 17 site-years across Kansas, United States. Replicated field trials evaluated tiller presence (removed or intact) in two hybrids (P0657AM and P0805AM) at three target plant densities (25000, 42000, and 60000 plants ha-1). Record of ears and kernels per unit area and kernel weight were collected separately for both main stalks and tillers in each plot. Indicated tiller contributions impacted the plasticity of yield components in evaluated genotypes. Ear number and kernel number per area were less dependent on plant density, but kernel number remained key to yield stability. Although ear number was less related to yield stability, ear source and type were significant yield predictors, with tiller axillary ears as stronger contributors than main stalk secondary ears in high-yielding environments. Certainly, managing for the most main stalk primary ears possible - that is, optimizing the plant density (which consequently reduces tiller expression), is desirable to maximize yields. However, the demonstrated escape from the deterministic hierarchy of corn yield formation may offer avenues to reduce corn management dependence on a seasonally variable optimum plant density, which cannot be remediated mid-season.

The Sustainability Crisis . . . Again

The Sustainability Crisis . . . Again

Harmfulness of cotton bollworm caterpillars on maize hybrids

Goal. Determine the damage to modern corn hybrids by the caterpillars of the cotton bollworm, develop a point scale for assessing the damage of kernels on the cob, and calculate the direct losses of grain yield.
 Methods. Field. The studies were carried in the research fields of the Cherkasy Research Station of Bioresources of the NSC «Institute of Agriculture of NAAS» 2017—2019. The cultivation of corn was carried out in accordance with the cultivation technology recommended for the Forest-Steppe zone of Ukraine, Cherkasy region. Plot size — 56 m2, in four replicates. Placement of plots — randomized. The number of damaged corncobs of cotton scoop was determined per hectare. To calculate the number of damaged kernels per corncobs, each damaged corn cobs was opened and the number of eaten and damaged kernels was counted. To calculate the direct yield losses for each corn hybrid, the total number of kernels eaten and damaged by the caterpillars of the cotton bollworm (per hectare) was calculated, which was multiplied by the mass of 100 kernels, respectively.
 Results. The degree of harmfulness of cotton bollworm caterpillars on maize hybrids of different maturity was investigated. In 2017—2019 The corncobs are most damaged in hybrids of the mid-maturing group — 58.4%, less — in early-maturing hybrids — 41.1%, and in the middle-early ones — 47.8%. For the first time, a nine-point scale was developed for assessing the defeat of caryopses on the cob by Helicoverpa armigera Hbn. caterpillars direct losses of grain yield are calculated. It was found that significant yield losses were observed in all mid-season maize hybrids (0.185—0.280 t/ha).
 Conclusions. In the Left-Bank Forest-Steppe of Ukraine, the cotton bollworm turned out to be a dangerous pest of the generative organs of corn. Therefore, the selection of resistant hybrids to attack by caterpillars of the cotton bollworm is a key element in the protection of this crop. And the nine-point scale developed by us allows us to assess the degree of damage to caryopses by the caterpillars of Helicoverpa armigera Hbn.

The content and characteristics of the accumulation of carotenoids in the grain of modern corn hybrids

The studies were carried out in 2018–2019 in the Belgorod region to identify hybrids and parental forms of corn with increased content of carotenoids in the grain. The material for the study was 4 domestic hybrids, 3 hybrids of the selection of Maizadur, 2 - Syngenta, 1 - Monsanto, 1 - Woodstock, standard - Belkorn 250 MB, as well as 4 parental components of the Decent SV hybrid. During the experiment, agricultural practices traditional for the region were used. The harvesting of the registration plots was carried out manually, considering the weight of the cobs and the harvesting moisture content of the grain. The content of carotenoids in grain was determined according to the developed method in terms of lutein. In 2018, a preliminary screening of a sample of hybrids was carried out. All studied hybrids, except for GIS 1 and GIS 3, surpassed the Belkorn 250 SV standard. The concentration of carotenoids in two domestic hybrids Resource SV (18.4 mg/kg) and Decent SV (19.8 mg/kg) surpassed the hybrids of the Maizadur selection by 35.9 and 40.4% of the Syngenta selection by 8.7 and 15, 2%, Monsanto - by 26.6 and 31.8%, Woodstock - by 8.2 and 14.6%, respectively. On average, over two years, the highest content of carotenoids in grain and their harvest per unit area was observed for the corn hybrid Decent DM (21.8 mg/kg and 169.4 g / ha, respectively), in which the values of these indicators exceeded the Belkorn 250 MV standard in 2 times. Among the parental components, the self-pollinated lines EM 10 3C (26.6 mg/kg) and SB 5-1 SV (29.7 mg/kg) were characterized by a high concentration of carotenoids - the parental components of the Decent SV hybrid.

Short-Term Effect of Nitrogen Fertilization on Carbon Mineralization during Corn Residue Decomposition in Soil

The effect of N fertilization on residue decomposition has been studied extensively; however, contrasting results reflect differences in residue quality, the form of N applied, and the type of soil studied. A 60 d laboratory incubation experiment was conducted to ascertain the effect of synthetic N addition on the decomposition of two corn (Zea mays L.) stover mixtures differing in C:N ratio by continuous monitoring of CO2 emissions and periodic measurement of microbial biomass and enzyme activities involved in C and N cycling. Cumulative CO2 production was greater for the high than low N residue treatment, and was significantly increased by the addition of exogenous N. The latter effect was prominent during the first month of incubation, whereas N-treated soils produced less CO2 in the second month, as would be expected due to more rapid substrate depletion from microbial C utilization previously enhanced by greater N availability. The stimulatory effect of exogenous N was verified with respect to active biomass, microbial biomass C and N, and cellulase and protease activities, all of which were significantly correlated with cumulative CO2 production. Intensive N fertilization in modern corn production increases the input of residues but is not conducive to soil C sequestration.

Effect of tillers on corn yield: Exploring trait plasticity potential in unpredictable environments

AbstractLong‐term selection in maize (Zea mays L.) favored single‐stalked phenotypes limiting vegetative growth. However, reduced plant densities create conducive environments to the expression of vegetative branches called tillers. Tiller expression has motivated discussions about its yield effect in variable environments, but tiller research is lacking for modern corn genotypes. The objectives of this study were to (a) quantify the relative importance of management, environment, and interactions on the yield effect of tiller expression for two modern genotypes; (b) understand effects of observed tiller density, plant density, and their interaction on yield; and (c) identify key environmental determinants of yield response to tiller density in modern genotypes. In 10 environmentally diverse site‐years across Kansas, tiller presence and removal were evaluated in two commercial corn hybrids (P0657AM and P0805AM) across three target plant density levels (25,000, 42,000, and 60,000 plants ha−1). Yields were increased or unaffected by greater plant densities and tiller presence within site‐years. Environments varied in yield responsiveness to tiller density, but fine‐tuning plant density was needed to maximize yields. Sites with yields most responsive to tiller density were characterized by good soil properties and photothermal quotient values (e.g., soils with high organic matter and climates with greater solar radiation and cooler temperatures). Favorable growing conditions can be exploited by plasticity traits such as tillering in unpredictable environments with annually variable optimum plant densities while limiting potential yield loss and producer risk due to disproportionate plant density.

Enhancement of Orientation of Corn Shelling Machine

Shelling is one of the most responsible and post-harvest operations of the plant. Production of various types of grain, peeled from the bark and traditionally. It is a traditional show of corn and the most time-consuming activities included hard work, grain loss and felling, chipping through a bite, using sticks, and using animals to step on multiple locations. Modern corn huskers tend to be large and heavy, high energy, which require high scaling capabilities. Additional expenses, the purchase of huskers, this is a high level of agriculture, small farmers-owners. Therefore, the aim of this study is to design, construct, and evaluate the performance of a small corn husker engine management system. It was built with both local, affordable materials and its cost is very low and affordable. The main components of the machine are: hood, scale block (musician, drum and concave), outer cover, shaft, frame and exhaust port. The location of these elements in relation to the belt and pulley. Engine capacity of 2 HP. provides drive through pipeline connections with the drive pulley show in between. Existing methods in the case of maize, de-zoom, the agro-industrial complex consists of crushing grain manually or using machines to the proper extent, and not one of them is effective, so as not to invest money in the development of the economy, public relations. Therefore, there is a need for an innovative idea for a product that is feasible, safe, cost-effective and efficient for the Indian farmer.

Location and Variety but Not Phosphate Starter Fertilization Influence the Profiles of Fatty Acids, Carotenoids, and Tocochromanols in Kernels of Modern Corn (Zea mays L.) Hybrids Cultivated in Germany.

Phosphate is a limiting plant nutrient and essential for corn growth and development. Thus, the impact of phosphate fertilization, location, and the variety of modern corn (Zea mays L.) hybrids on the profiles of fatty acids, carotenoids, and tocochromanols (vitamin E) was assessed in corn grains. Eight different corn hybrids were grown with (52.9 kg of phosphorus per ha) or without starter fertilizer at three experimental sites in Germany. Location (p < 0.05) and genetics (p < 0.001) but not phosphate fertilization significantly altered the concentrations of individual saturated and unsaturated fatty acids, carotenoids, and tocochromanols. Significant (p < 0.05) interaction effects on the concentrations were mainly observed between the variety and the location. In conclusion, the choice of the corn variety had a more significant impact on the biosynthesis of fatty acids, carotenoids, and tocochromanols than the location or phosphate application on phosphate-sufficient soils.

Corn Tiller Yield Contributions and Ear Development in Low Plant Densities

Research in modern corn (Zea mays L.) hybrids investigating tiller contributions and ear development at low plant densities is scarce, particularly in water-limited environments. To fill this research gap, a second season of replicated experiments was conducted in 2020 at 7 sites across Kansas (Keats, Buhler, Greensburg, Garden City, Goodland, and two sites in Colby) evaluating two common, tiller-prone corn hybrids (P0805AM and P0657AM) at three target plant density levels (10000, 17000, and 24000 plants/a). Five of the listed sites also considered a tillering factor (tiller removal at development stage V10 [tenth-leaf] or tiller maintenance). Seasonal phenology, partitioned grain yield, harvested ear type characterizations, and environmental conditions were recorded and analyzed to quantify tiller contributions in each site. Results showed that intact tillers had either no effect or were able to boost yields. In the best environments, tillers were able to successfully compensate for losses of 60% in plant density. Five of the seven tested sites produced approximately 50% of total harvested ears as desirable tiller lateral ears in the 10000 plants/a target plant density. The highest percentage of undesirable tiller tassel ear development in the 10000 plants/a density was 13%. Future research will seek to find explanations of the ear type relationships on a deeper level and predict tiller yield contributions considering various environments and ear development outcomes.

Adaptive abilities of corn hybrids under different irrigation modes and moisture supply in the arid Steppe of Ukraine

Aim. The study presents the results of the research on the productivity features and adaptability parameters of domestic corn hybrids under different irrigation modes and water supply under conditions of the Arid Steppe. Methods. The general scientific, special selection genetic, computational and comparative research methods were used. The research object was modern corn hybrids of domestic selection of different maturity groups. The hybrids were sown under different irrigation modes (common sprinkling, drip irrigation, sub-irrigation). Results. The retrospective analysis of the productivity of main grain crops in the area of the Arid Steppe over a 130-year period showed that the highest rates of an increase in productivity were recorded in corn. An annual increase in its productivity was 31 kg/ha per year and it was due to the use of new varieties (hybrids) and the improvement of growing techniques. Irrigation made it possible to realize potential productivity of new hybrids and increase the productivity from 6.59 to 82.3 c/ha. Productivity rose 12.5 times over a 130-year period, the annual increase being 58 kg/ha per year. Without irrigation the grain productivity was the highest in early-maturing hybrids – 3.28 and 3.05 t/ha indicating their high drought resistance. The use of these hybrids is appropriate under conditions of water-saving irrigation modes on irrigated lands with a low hydro-module and on dry massifs. A fall in the productivity under other irrigation modes was from 0.41 to 1.93 t/ha. Conclusions. Under irrigation conditions it is necessary to use corn hybrids with a genetically programmed reaction to optimal growing conditions (an optimal mode of soil moisture and mineral nutrition).&#x0D; Keywords: hybrid, corn, irrigation, adaptability, drought resistance, grain, selection.

Special Issue No. – 10, June, 2020 Journal &gt; Special Issue &gt; Special Issue No. – 10, June, 2020 &gt; Page 5 “Quantative Methods in Modern Science” organized by Academic Paper Ltd, Russia MORPHOLOGICAL AND ANATOMICAL FEATURES OF THE GENUS GAGEA SALISB., GROWING IN THE EAST KAZAKHSTAN REGION Authors: Zhamal T. Igissinova,Almash A. Kitapbayeva,Anargul S. Sharipkhanova,Alexander L. Vorobyev,Svetlana F. Kolosova,Zhanat

Special Issue No. – 10, June, 2020 Journal &gt; Special Issue &gt; Special Issue No. – 10, June, 2020 &gt; Page 5 “Quantative Methods in Modern Science” organized by Academic Paper Ltd, Russia MORPHOLOGICAL AND ANATOMICAL FEATURES OF THE GENUS GAGEA SALISB., GROWING IN THE EAST KAZAKHSTAN REGION Authors: Zhamal T. Igissinova,Almash A. Kitapbayeva,Anargul S. Sharipkhanova,Alexander L. Vorobyev,Svetlana F. Kolosova,Zhanat

Performance evaluation of an electric corn shelling machine for small scale indigenous industries in Nigeria

The time and energy expended in shelling corn manually have necessitated the detailed design and construction of a modern electric corn shelling machine. The major problems associated with the manual corn shelling machine were the high level of fatigue of the operator and low shelling capacity, leading to reduced productivity. These problems motivated the construction of a sheller with a simple design, that employs a swift mechanism and pulley drive, is simple to use and maintain and results in improved efficiency. Results obtained show that the electric corn shelling machine developed in this study is cost effective and has a shelling efficiency of 91.4%, whereas the manual corn sheller was shown to have an efficiency of 45% or less. Therefore, if the electric corn shelling machine were used, especially in rural settings, it could optimize the time and energy currently taken to shell corn manually on a large scale.

Agronomic Response of Corn (Zea maysL.) Hybrids to Plant Populations

Field studies were conducted in 2016 and 2017 under rain-fed conditions in south-central Louisiana, (a) to determine the effects of plant density levels on plant height, ear height, stalk diameter, lodging, corn grain yield, test weight, and photosynthetically active radiation with modern corn hybrids in central Louisiana and (b) to test the hypothesis that the response of grain yield to plant population density would depend on the reproductive plasticity (flex, semiflex, or fixed ear) of the hybrids evaluated. Rainfall was above average while air temperatures were below average during the growing season in both years. Grain yield showed a hybrid response in one of two years (fixed ear greater than semiflex ear) while yields increased as plant populations increased. Test weights were less with the fixed ear hybrid and the effect of plant populations was inconsistent with increased populations resulting in greater test weight in one of two years. Lodging increased as plant populations increased with the fixed ear hybrid resulting in greater lodging in one of two years. There was a hybrid by plant population interaction for ear height and seed weight. The effect of plant populations is an important factor for corn yield; however, yield gains associated with higher plant populations may be dependent on the genetic predisposition of corn hybrids (regardless of the reproductive plasticity) to tolerate various environmental conditions and stresses associated with higher populations.

A 1,000-Year-Old RNA Virus.

Only a few RNA viruses have been discovered from archaeological samples, the oldest dating from about 750 years ago. Using ancient maize cobs from Antelope house, Arizona, dating from ca. 1,000 CE, we discovered a novel plant virus with a double-stranded RNA genome. The virus is a member of the family Chrysoviridae that infect plants and fungi in a persistent manner. The extracted double-stranded RNA from 312 maize cobs was converted to cDNA, and sequences were determined using an Illumina HiSeq 2000. Assembled contigs from many samples showed similarity to Anthurium mosaic-associated virus and Persea americana chrysovirus, putative species in the Chrysovirus genus, and nearly complete genomes were found in three ancient maize samples. We named this new virus Zea mays chrysovirus 1. Using specific primers, we were able to recover sequences of a closely related virus from modern maize and obtained the nearly complete sequences of the three genomic RNAs. Comparing the nucleotide sequences of the three genomic RNAs of the modern and ancient viruses showed 98, 96.7, and 97.4% identities, respectively. Hence, in 1,000 years of maize cultivation, this virus has undergone about 3% divergence.IMPORTANCE A virus related to plant chrysoviruses was found in numerous ancient samples of maize, with nearly complete genomes in three samples. The age of the ancient samples (i.e., about 1,000 years old) was confirmed by carbon dating. Chrysoviruses are persistent plant viruses. They infect their hosts from generation to generation by transmission through seeds and can remain in their hosts for very long time periods. When modern corn samples were analyzed, a closely related chrysovirus was found with only about 3% divergence from the ancient sequences. This virus represents the oldest known plant virus.

Corn’s Ancestor Could Help It Go Green

The grandfather of modern corn may hold the key to reducing its need for chemical fertilizers.

Over‐Fertilization Does Not Build Soil Test Phosphorus and Potassium in Ohio

Core IdeasCorn and soybean yield seldom responded to P and K fertilization over 9 yr.Soil test P and soil test K significantly decreased from values initially in the recommended maintenance range.Corn Leaf P and Leaf K was often below the sufficiency concentration.Appropriate P and K fertilizer recommendations for corn (Zea maysL.) and soybean [(Glycine max(L.) Merr.] in Ohio are essential, as water quality and nutrient management issues in the region have intensified over the last several years. The objectives of this study were to: (i) evaluate corn and soybean grain yield response to P and K fertilization, (ii) examine soil test phosphorus (STP) and potassium (STK) and corn Leaf P and Leaf K trends, and (iii) compare the ability of soil and leaf tissue testing to reflect corn and soybean response to fertilization. We evaluated three P and K fertilizer rates, no fertilizer (0×), an estimated nutrient removal rate (1×), and twice the estimated nutrient removal rate (2×), in corn–soybean rotations at three sites over 9 yr. Grain yield was generally non‐responsive to P and K fertilization, with only 9 of 42 site‐years yielding significantly positive responses. Soil test P and K started in the maintenance range, but significantly declined with the 1× rate at two of three sites for P and at all sites for K. Furthermore, the 2× rate of P and K failed to build STP and STK at any site, with significant declines at one site. The results revealed an inability to maintain initial STP and STK levels with the 1× rate and call into question the suitability of current fertilizer P and K recommendations aimed at maintaining STP and STK. These recommendations require updating to better reflect fertilizer needs of modern corn and soybean.