Maize Stalk Research Articles

Effects of Combined Pollution of Microplastics and Lead on Maize Seed Germination and Growth

Microplastics are a new contaminant that are causing worldwide concern. However, an understanding of their impact on agricultural seed germination remains inadequate. To investigate the effects of combined microplastic and heavy metal contamination on crop seed germination and growth, the effects of exposure to different single and combined concentrations of lead (Pb) and three microplastics[polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC)] on maize seed germination and growth were investigated using maize seeds. The results showed that:the inhibition of maize seed germination by Pb single exposure generally increased with Pb concentration. Compared with that in CK, 500, 1000, and 1500 mg·L-1 PE exposure significantly inhibited maize seed germination, but 100 and 300 mg·L-1 exposure had no significant effect (except at d 5). All PP concentration exposures significantly inhibited maize seed germination, with higher concentrations resulting in stronger inhibition. Compared to that under PP and PE exposure, PVC single exposure inhibited maize germination less, and 500, 1000, and 1500 mg·L-1 exposures produced a facilitative effect at the later stages of germination. The germination index, germination potential, and vigor index of maize seeds decreased with the increase in the single exposure concentration of lead and three types of microplastics, significantly decreased compared with that of CK under the combined exposure of Pb and PE, and did not change significantly under the combined exposure of PP and Pb or PVC and Pb. Among the three types of microplastics, PVC had the least effect on corn seed vigor. Both single exposures of 10 mg·L-1Pb and 100 mg·L-1 of the three microplastics promoted maize stalk and root growth, whereas other concentrations showed mostly inhibitory effects. When the PE concentration was 500 mg·L-1, the 10 and 20 mg·L-1Pb exposures both promoted maize seed stalk and root growth; however, the combined PP and Pb exposures did not produce significant inhibition, whereas 500 mg·L-1PVC and 10 mg·L-1Pb showed the strongest inhibition of maize stalk and root growth under combined PVC and Pb exposures. The effects of combined exposure to microplastics and Pb on the germination and growth of maize seeds were essentially antagonistic, thus slowing down the toxic effects of their respective single exposures on maize seeds.

Combustion Performance of Agropellets in an Experimental Fixed Bed Reactor versus a Commercial Grate Boiler. Validation of Ash Behavior.

Agrobiomass is presented as a suitable alternative to contribute to the fossil fuel decarbonization strategy at the European level. To achieve the ambitious objectives established in this regard: (i) new biomass resources need to be used and therefore initially tested in order to confirm its potential for different applications, such as energy production, and (ii) biomass supply capacity needs to be enlarged; therefore, agroindustries converted into Integrated Biomass Logistic Center (IBLC) can play a key role. In this research, eight different agropellets (blends of wheat straw and maize stalk with forestry wood) were produced in a IBLC and tested in a commercial boiler, comparing the results with previous ones obtained in a fixed bed reactor test campaign and to a base case (woody pellets). This paper includes both individual results in terms of bottom ash, deposition, and a final comparison of ash behavior in both facilities. All biofuels tested showed an adequate performance in terms of efficiency and emissions, being slightly better for the agropellets produced with wheat straw. Regarding sintering and deposition, the tendencies found in the reactor investigation were also observed in the commercial boiler. Moreover, the assessment of the results from the boiler and reactor's tests proved that reactor experiments are representative and may be used to test new biofuels more efficiently in terms of effort and time allocated and could be used to predict sintering and deposition phenomenon occurrence.

An overview on non-wood fiber characteristics for paper production: Sustainable management approach

The amount of paper and paperboard a country uses are a reliable barometer of its development. Having access to them is essential to our daily life. The Indian paper industry faces a number of challenges, one of which is a scarcity of high-quality raw materials. Agricultural waste products have become essential alternative sources of supply as a result of an increase in the need for fibrous raw materials, a global lack of trees, and a growing awareness of sustainability. When compared to the manufacturing of pulp and paper from wood sources, the use of non-wood sources (including bagasse, maize stalks, cotton stalks and rice straws) offers a number of advantages. These benefits include superior quality of the bleached pulp and excellent sources for specialty papers. Paper manufacture is more ecologically friendly and sustainable when non-wood fibers are processed since non-wood pulping technologies use less energy than wood-based pulping processes. Furthermore, the financial advantages include cost savings, market differentiation, enhanced sustainability, and access to government subsidies. By investing in non-wood fibers to satisfy rising customer demand for environmentally friendly goods, paper manufacturers may position themselves for long-term prosperity and environmental responsibility. The non-wood fibers are cellular and have a complex cell wall structure. A thorough understanding of their properties is essential for effective use. Therefore, the objective of the present review is to explore the wide variation between critical characteristics (morphological, chemical, and mechanical) and the most appropriate pulping and bleaching processes for commonly used agricultural residues (Rice straw, Bagasse, Wheat straw and Bamboo) in the Indian pulp and paper industry for the production of paper, board, and packaging.

Visual detection of Fusarium temperatum by using CRISPR-Cas12a empowered LAMP assay coupled with AuNPs-based colorimetric reaction

Fusarium temperatum (F. temperatum) causes maize stalk rot disease, reducing grain yield and producing multiple harmful mycotoxins that threaten food safety and quality. However, current detection methods are limited by the requirement of well-trained personnel, complicated operations and expensive instruments. To address this challenge, gold nanoparticles (AuNPs)-based colorimetric assay using loop-mediated isothermal amplification (LAMP) coupled with CRISPR-Cas12a (Au-CRISPR) was tested for F. temperatum detection. The assay utilizes DNA-modified AuNPs as a colorimetric probe and the results can be readily observed by the naked eye. After optimization, the method can specifically detect as low as 100 copies/μL of target DNA or 10−8 ng/μL of extracted DNA from F. temperatum. The detection platform allows high-throughput testing by integrating microtiter plates and microplate reader. Furthermore, a portable smartphone-based device was developed to realize point of care (POC) detection of F. temperatum in resource-limited settings. This simple, inexpensive and sensitive detection platform has great potential for the applications in field detection.

Experimental error analysis of biomechanical phenotyping for stalk lodging resistance in maize

Stalk lodging destroys between 5 and 25% of grain crops annually. Developing crop varieties with improved lodging resistance will reduce the yield gap. Field-phenotyping equipment is critical to develop lodging resistant crop varieties, but current equipment is hindered by measurement error. Relatively little research has been done to identify and rectify sources of measurement error in biomechanical phenotyping platforms. This study specifically investigated sources of error in bending stiffness and bending strength measurements of maize stalks acquired using an in-field phenotyping platform known as the DARLING. Three specific sources of error in bending stiffness and bending strength measurements were evaluated: horizontal device placement, vertical device placement and incorrect recordings of load cell height. Incorrect load cell heights introduced errors as large as 130% in bending stiffness and 50% in bending strength. Results indicated that errors on the order of 15–25% in bending stiffness and 1–10% in bending strength are common in field-based measurements. Improving the design of phenotyping devices and associated operating procedures can mitigate this error. Reducing measurement error in field-phenotyping equipment is crucial for advancing the development of improved, lodging-resistant crop varieties. Findings have important implications for reducing the yield gap.

Evaluation of influencing factors on the location and displacement of Ostrinia nubilalis larvae in maize stalks measured by computed tomography

Evaluation of influencing factors on the location and displacement of Ostrinia nubilalis larvae in maize stalks measured by computed tomography

Synergistic Effects and Kinetics in Co-Pyrolysis of Waste Tire With Five Agricultural Residues Using Thermogravimetric Analysis

Abstract Continued social and mobility development has caused a sharp increase in the number of waste tires, increased environmental pollution, and waste of limited resources. Agricultural residues as a bioresource, which has drawn increased attention in recent years. The thermochemical conversion of waste tires and agricultural residues and their mixtures offers important prospects for scientific development, which can provide energy security and a much reduced environmental footprint. In this paper, pyrolysis of waste tires and its co-pyrolysis with maize stalk, wheat straw, cotton stalk, rape straw, or peanut shell agricultural residues, in mass ratios of 1:1 were investigated at different heating rate using thermogravimetric analysis. The kinetic parameters were calculated using Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) kinetic models at heating rates of 20, 30, and 50 °C/min. The synergistic effect between waste tires and agricultural residues was explored by calculating the deviation between the experimental and calculated values. The results showed the presence of a synergistic effect between the co-pyrolysis of waste tires and the residual agricultural residues. In the kinetic analysis, activation energies of waste tires, agricultural residues, and their mixtures were calculated using the two models. The reaction followed a multistage reaction mechanism. The differential thermogravimetry behavior of the mixture was similar to the weighted aggregate results of the waste tire and agricultural waste samples, pyrolyzed separately. These results provide some insights into the combined treatment of waste tires and agricultural waste residues.

Development and stochastic validation of a parameterized model of maize stalk flexure and buckling

Abstract Maize stalk lodging is the structural failure of the stalk prior to harvest and is a major problem for maize (corn) producers and plant breeders. To address this problem, it is critical to understand precisely how geometric and material parameters of the maize stalk influence stalk strength. Computational models could be a powerful tool in such investigations, but current methods of creating computational models are costly, time-consuming and, most importantly, do not provide parameterized control of the maize stalk parameters. The purpose of this study was to develop and validate a parameterized 3D model of the maize stalk. The parameterized model provides independent control over all aspects of the maize stalk geometry and material properties. The model accurately captures the shape of actual maize stalks and is predictive of maize stalk stiffness and strength. The model was validated using stochastic sampling of material properties to account for uncertainty in the values and influence of mechanical tissue properties. Results indicated that buckling is influenced by material properties to a greater extent that flexural stiffness. Finally, we demonstrate that this model can be used to create an unlimited number of synthetic stalks from within the parameter space. This model will enable the future implementation of parameter sweep studies, sensitivity analysis and optimization studies, and can be used to create computational models of maize stalks with any desired combination of geometric and material properties.

The causal agent and the distribution of maize stalk rot disease in the Tanah Laut Regency, South Kalimantan

Stalk rot disease, which can be caused by fungi and bacteria, is a common problem in maize cultivation. The infection of the disease started in 2019 in Tanah Laut Regency with an attack area of 4.7 hectares. The attack area increased to 27.5 hectares in 2020. This study aimed to identify the causal agent of maize stem rot disease in Tanah Laut Regency and how it spread throughout the regency. The study started with the identification of the pathogen in the field. The result showed that maize stalk rot disease in Tanah Laut Regency was caused by Pythium and Fusarium genera of fungi and Pantoea, Erwinia, Dickeya and Pectobacteria genera of bacteria. This disease spread to 10 out of 11 sub-districts in Tanah Laut Regency, with an attack intensity ranging from 1 to 22%.

The influence of water content on the longitudinal modulus of elasticity of maize stalk pith and rind tissues

BackgroundModern computational modeling could provide the key to obtaining new insights into the mechanisms of maize stalk failure as well as suggesting new ways to improve stalk strength. However, a complete set of mechanical properties of maize tissues is required to enable computational modeling of maize stems. This study developed two compression test methods for obtaining the longitudinal modulus of elasticity of both rind and pith tissues, assessed the influence of water content on tissue properties, and investigated the relationship between rind modulus and pith modulus. These methods involved uniform 5–7 cm segments of maize stems which were scanned using a flatbed scanner then tested in compression using a universal testing machine in both intact and dissected (rind-only and pith-only) states.ResultsThe modulus of elasticity of pith tissues was highest for fully turgid specimens and decreased as water was removed from the specimens. Water content was negatively correlated with the modulus of elasticity of the rind. Rind and pith tissues were found to be weakly correlated. The median ratio of rind modulus to pith modulus was found to be 17. Of the two methods investigated, the pith-only specimen preparation was found to be simple reliable while the rind-only method was found to be adversely affected by lateral bowing of the specimen.ConclusionsResearchers can use the information in this paper to improve computational models of maize stems in three ways: (1) by incorporating realistic values of the longitudinal modulus of elasticity of pith and rind tissues; (2) by selecting pith and rind properties that match empirically observed ratios; and (3) by incorporating appropriate dependencies between these material properties and water content. From an experimental perspective, the intact/pith-only experimental method outlined in this paper is simpler than previously reported methods and provides reliable estimates of both pith and rind modulus of elasticity values. Further research using this measurement method is recommended to more clearly understand the influence of water content and turgor pressure on tissue properties.

Characterization of Dissolved Organic Matter Released from Aged Biochar: A Comparative Study of Two Feedstocks and Multiple Aging Approaches.

Dissolved organic matter (DOM) plays important roles in environmental ecosystems. While many studies have explored the characteristics of aged biochar, limited information is available about the properties of DOM derived from aged biochar. In this study, biochar obtained from maize stalk and soybean straw were aged using farmland or vegetable-soil solution, as well as soil solution containing hydrogen peroxide (H2O2). Chemical composition of the extracted DOM from the aged biochar was analyzed via excitation-emission matrix coupled with fluorescence regional integration (FRI) and parallel factor analysis (PARAFAC). Obtained results showed that biochar aged with H2O2-enriched soil solution had higher water-soluble organic carbon, ranging from 147.26-734.13% higher than the controls. FRI analysis revealed fulvic and humic-like organics as the key components, with a considerable increase of 57.48-235.96% in the humic-like component, especially in soybean-straw-aged biochar. PARAFAC identified four humic-like substance components. Concurrently, the aromaticity and humification of the aged-biochar-derived DOM increased, while the molecular weight decreased. These findings suggest that DOM derived from aged biochar, with a high content of humic-like organics, might impact the mobility and toxicity of pollutants in soil.

Development and Performance Evaluation of Maize Stalk Harvester

A power operated maize stalk harvester was designed and developed in the Dept. of Farm Machinery and Power Engineering, MPUAT, Udaipur, Rajasthan during 2018-19. The objective of this study is to optimize the operational parameters of the maize stalk harvesting by using the RSM techniques. The effects of independent parameters i.e., blade speed (2000, 4000 and 6000 rpm) and stalk moisture content (38, 42 and 46%) on cutting efficiency (%) and fuel consumption (l/h) were studied. To correlate the independent parameters with the dependent parameters, the central composite rotatable design (CCRD) method with a quadratic model was used. The findings indicated that the variations in blade speed and stalk moisture content affected the cutting efficiency (%) and fuel consumption (l/h). To assess the statistical significance of the model, an analysis of variance (ANOVA) was performed, which showed good agreement between the experimental data and data predicted by the model. The blade speed of 4000 rpm and stalk moisture content of 46.0% was found to be the optimum for power operated maize stalk harvester with the 96.52% cutting efficiency and 0.72 l/h fuel consumption.

Identification of ZmBK2 Gene Variation Involved in Regulating Maize Brittleness.

Maize stalk strength is a crucial agronomic trait that affects lodging resistance. We used map-based cloning and allelic tests to identify a maize mutant associated with decreased stalk strength and confirmed that the mutated gene, ZmBK2, is a homolog of Arabidopsis AtCOBL4, which encodes a COBRA-like glycosylphosphatidylinositol (GPI)-anchored protein. The bk2 mutant exhibited lower cellulose content and whole-plant brittleness. Microscopic observations showed that sclerenchymatous cells were reduced in number and had thinner cell walls, suggesting that ZmBK2 affects the development of cell walls. Transcriptome sequencing of differentially expressed genes in the leaves and stalks revealed substantial changes in the genes associated with cell wall development. We constructed a cell wall regulatory network using these differentially expressed genes, which revealed that abnormal cellulose synthesis may be a reason for brittleness. These results reinforce our understanding of cell wall development and provide a foundation for studying the mechanisms underlying maize lodging resistance.

Litter mixing promoted decomposition and altered microbial community in common bean root litter

BackgroundDecomposition of plant litter is a key driver of carbon and nutrient cycling in terrestrial ecosystems. Mixing litters of different plant species may alter the decomposition rate, but its effect on the microbial decomposer community in plant litter is not fully understood. Here, we tested the effects of mixing with maize (Zea mays L.) and soybean [Glycine max (Linn.) Merr.] stalk litters on the decomposition and microbial decomposer communities of common bean (Phaseolus vulgaris L.) root litter at the early decomposition stage in a litterbag experiment.ResultsMixing with maize stalk litter, soybean stalk litter, and both of these litters increased the decomposition rate of common bean root litter at 56 day but not 14 day after incubation. Litter mixing also increased the decomposition rate of the whole liter mixture at 56 day after incubation. Amplicon sequencing found that litter mixing altered the composition of bacterial (at 56 day after incubation) and fungal communities (at both 14 and 56 day after incubation) in common bean root litter. Litter mixing increased the abundance and alpha diversity of fungal communities in common bean root litter at 56 day after incubation. Particularly, litter mixing stimulated certain microbial taxa, such as Fusarium, Aspergillus and Stachybotrys spp. In addition, a pot experiment with adding litters in the soil showed that litter mixing promoted growth of common bean seedlings and increased soil nitrogen and phosphorus contents.ConclusionsThis study showed that litter mixing can promote the decomposition rate and cause shifts in microbial decomposer communities, which may positively affect crop growth.

Optimizing nitrogen management enhances stalk lodging resistance and grain yield in dense planting maize by improving canopy light distribution

Enhancing the basal internode mechanical strength by improving the canopy light distribution of dense planting maize to reduce the lodging rate is important for establishing a high-yielding and stable population. A three-year field experiment was carried out at three densities treatments (5.25 × 104, 6.75 × 104 and 8.25 × 104 plants hm−2) × four nitrogen fertilizer treatments (0, 120, 180 and 240 kg hm−2) to study canopy light distribution and stalk lodging resistance characteristics. Results showed that grain yield was increased 3.31–14.68% under 6.75 × 104 plants hm−2 treatment compared to 5.25 × 104 plants hm−2. Meanwhile, plant morphology was altered with the increasing of planting density, light interception rate at lower-middle canopy position (0–150 cm) was decreased 15.10%, thus the mechanical strength of the basal internodes was reduced, and the lodging rate was increased 4.66% points. The formation of maize stalk lodging resistance and grain yield was promoted by the nitrogen fertilizer application. The N180 treatment improved mechanical strength by enhancing canopy light distribution and optimizing internode quality, lodging rate was decreased 6.31–17.22% compared to the N240 treatment while only a 0.54–7.54% reduction in grain yield, finally. Analysis the relationship between characteristic factors and mechanical strength, we found that internode plumpness (explained the 85.6% percentage of variability) was the key factor affecting basal internode mechanical strength. Our results will assist breeders in breeding lodging-resistant hybrids and agronomists improving field management practices for low lodging rate and high yield, and will be equally illuminating for other maize-producing regions.

Effect of Pyrolysis Temperature on Chemical and Structural Properties of Raw Agricultural Wastes

This study was carried out to assess the effect of charring on chemical and structural properties of raw agricultural wastes at two different temperatures. The agricultural wastes (feather from the poultry unit, maize cob, maize stalk, bamboo, rice straw, cocoa pods, maize husk and used paper from offices) were collected from Teaching and Research Farm, Obafemi Awolowo University (OAU), Ile-Ife, Osun State, Ife excluding the used paper, which was collected from the Academic areas, OAU. The collected waste materials were air-dried, pulverized, ground, and sieved with 2 mm sieve separately. Biochars were produced from raw agricultural wastes at pyrolysis temperatures 400℃ and 450℃. The raw and selected charred agricultural wastes were subjected to chemical and structural analyses. Pyrolysis of the raw materials at the two temperatures led to a significant increase in pH. A significant decrease in organic carbon of all the agricultural waste materials was observed after pyrolysis, a lower C:N was recorded; however, nitrogen content did not change significantly with pyrolysis temperature compared with the raw waste materials. The concentrations of cations like Ca and Mg were unaffected by the pyrolysis temperatures, but significant increase was observed with potassium. The results of FTIR analysis indicated the presence of many surface functional groups in both the raw and charred materials, such as OH, COOH and NH, that could be involved in adsorption and release of plant nutrients in soils, including heavy metals adsorption from soil. However, the intensities of the functional groups were lower in raw agricultural wastes compared with charred agricultural waste. The effect of temperature differences was not significant on the elemental and structural properties; thus, any could be taken as the optimum temperature for effective biochar production. It was concluded that biochar produced from agricultural wastes could be used as liming materials and soil amendments. Also, the presence of carboxylic and phenolic groups in the charred materials will increase the soil cation exchange capacity and improve the nutrient holding capacity of the soil.

Long‐term fertilization and plastic film mulching modify temporal incorporation of 13C/15N‐labelled particulate organic matter

AbstractPlastic film mulching (PFM) is critical for agricultural planting and maximizing production in semiarid and arid areas. Particulate organic matter (POM) is assumed to be a sensitive indicator for evaluating the effects of different agricultural practices on soil fertility and the soil organic carbon (SOC) pool. Soil aggregates have the function of ‘wrap’ and protect the POM stored in them. However, there is limited information regarding how PFM and fertilization jointly influence the dynamic changes of newly added stalk‐derived POM in brown earth. Consequently, an in‐depth study of the fate of carbon (C) and nitrogen (N) derived from maize stalk residues within the particulate organic carbon (POC) and particulate organic nitrogen (PON) fractions in soil aggregates was undertaken. Its outcome would contribute to better predictions on the active organic matter components sequestered in the soil. The dynamics and accumulation of newly added maize stalk C and N as POC and PON in different soil aggregates (using the dry sieving method divided into >2, 1–2, 0.25–1 and <0.25 mm) were analysed by an in situ 13C/15N‐tracing technique under PFM and different fertilization treatments. Over 360 days of cultivation, the POC and PON contents were significantly (p < 0.05) larger in the nitrogen (N) and organic manure (M) treatments than in the MN (manure combined with nitrogen) and Control treatments. The PFM treatment accelerated the decomposition of maize stalk C in the N fertilizer treatment, with an increase of 64% in stalk‐derived POC after the 1‐day cultivation period. Stalk‐derived POM tended to accumulate in <0.25 mm microaggregates in the early cultivation period and then decreased rapidly with the extension of the cultivation period affected by PFM coupled with fertilization. However, stalk‐derived POM accumulation in macroaggregates (>0.25 mm) fluctuated over the 360‐day cultivation period. Accordingly, PFM application and fertilization practices had important effects on the accumulation of newly added stalk‐derived POM in soil aggregates. We conclude that the accumulation of maize residue POM was primarily affected by soil fertilization type, rather than by the presence or absence of PFM. These results provide new insights into agricultural management strategies for improving soil carbon sequestration capacity.

An investigation on agricultural wastes as soil stabilizers

The primary purpose of our study is to boost the compressive strength of expansive soil in the Chennai region by incorporating BAGASSE ASH and RICE STRAW ASH as additives to increase the soil's stability and decrease its swelling. This will enable us to reach our primary goal of boosting the compressive strength of expanding soil in the region. One of our objectives was to increase the compressive strength of expansive soil, and this will assist us achieve that objective. A series of distinct experiments are conducted, with each utilising a different section of the expanding soil. Expansive soil is considered a potential natural hazard since it can cause considerable damage to buildings and other structures if not treated appropriately. If this issue is not resolved, there is a greater chance that damage will occur. Lime, fly ash, rice husk ash, corn stalk ash, and various other forms of ash were among the numerous components utilised in the stabilisation of the soil. Other constituents were maize stalk ash, rice husk ash, and further forms of ash. The percentages of BA and SA in the soil sample utilised for the experiment were 1%, 2%, 3%, and 4%, respectively. These numbers were utilised during the study. The primary objective of this project is to conduct a comparative analysis of BA and SA to assess their combined strength with a soil sample. This will be accomplished by contrasting and comparing the outcomes of various analyses. When varying amounts of BA and SA were added to the mixture, the tests revealed that both the maximum dry density and the optimal moisture content increased. This was the case regardless of the BA and SA amounts utilised. It is proved that the soil condition would improve if the optimal mixture of 2% BA and 1% SA were applied. This suggests that the SA is capable of achieving a higher level of stability than the BA. According to the findings of this study, it is possible that it may be utilised effectively for the purpose of soil stabilisation, and as a consequence, both the desired level of quality and the desired level of economy might be attained.

Evaluation of Inoculation Methods for Determination of Winter Wheat Resistance to Fusarium Head Blight

One of the most severe winter wheat (Triticum aestivum L.) diseases is Fusarium head blight (FHB). It is believed that selection for resistance to FHB is better in high disease pressure environments, for which various methods of artificial inoculation are used. The standard spray method of artificial inoculation is believed to be technically demanding and labour intensive. Therefore, scattering Fusarium-infected maize stalks onto trial plots after wheat emergence is suggested as a suitable alternative. The aim of this study was to compare the mean values and heritability of the visual rating index (VRI) and the percentage of Fusarium-damaged kernels (FDK) between the two abovementioned methods of artificial inoculation and natural infection, and to determine the phenotypic correlations between the three methods for the studied traits. The achieved levels of VRI and FDK were comparable for the two methods of artificial inoculation and considerably lower under natural conditions. Heritability for VRI ranged over four years from 0.68 to 0.91 for the spray method, from 0.73 to 0.95 for the infected maize stalks, and from 0.26 to 0.65 for natural infection, whereas for FDK it ranged from 0.56 to 0.85, 0.38 to 0.83, and 0.11 to 0.44 for the three inoculation methods, respectively. The strong positive correlation between the two applied methods of artificial inoculation for studied traits suggests that scattering infected maize stalks could serve as a reliable supplement for the technically and labor-intensive spray method of artificial inoculation.

Experimental Study on the Effect of Water Jet Cutting Parameters on Maize Stalks

Cutting maize stalks using water jet cutting technology is a new method of stalk management before no-tillage sowing. Aiming to cut off the maize stalks (stems and stem nodes), we conducted an all-factor cutting experiment on stems and single-factor cutting experiments on stem nodes under different cutting parameters. The results showed that the cutoff ratio of the stems and stem nodes increased with water jet pressure and decreased with target distance and traverse speed. For cutting off the stems with a maximum traverse speed, the parameters were 120 MPa water jet pressure, 10 mm target distance, and 1371 mm/min traverse speed. When the target distance was 30 mm, the traverse speed was 4000 mm/min, and the water jet pressure was greater than or equal to 160 MPa, the cutoff ratio of stem nodes was 100%. Therefore, the water jet pressure ≥ 160 MPa, the target distance ≤ 10 mm, and the traverse speed ≤ 1371 mm/min were needed to cut off both. Moreover, bottom burrs, surface stripes, and cutting residue might appear due to the divergent and lagging characteristics of water jets. The results could provide basic data and technical support for cutting maize stalks with water jets.