Corn Seeds Research Articles

Development of a Mexican corn landrace, Northern Conical, under temperature and rainfall conditions predicted by the middle of this century: an experimental field approach

Background: Corn is the most important crop in Mexico, but it can be affected by climate change. Small farmers from arid and semiarid ecosystems mainly use rainfed native landraces with short productive cycles (less than 90 days), which are adapted to elevated temperatures and intense drought. Among these landraces we can find the Norther Conical corn. Hypothesis: As Northern Conical seems to be adapted to arid agroecosystems, we hypothesize that this corn landrace can tolerate the mid-century climate change conditions. Studied species: Zea mays subsp. mays (Poaceae), Northern Conical landrace. Study site and dates: An abandoned agricultural field in San Luis Potosí, central Mexico, between August and October 2022. Methods: In a field experiment, corn seeds were sowed under the conditions of higher temperature and lower rainfall predicted by the middle of this century (period 2041-2060), as well as under the current climate. Emergence and survival of plants were regularly monitored, and their functional responses were measured by the end of the experiment. Results: Northern Conical plants performed better (in terms of emergence, survival, growth rates, and photosynthetic performance) under higher temperature and lower rainfall, as compared with those developed under the current climate. Conclusions: Our results suggest that the Northern Conical corn landrace may tolerate the increases in aridity expected in the short term. However, simulations under contrasting environmental and ontogenetical conditions are needed.

Solid-state anaerobic digestion of sweet corn waste: The effect of mixing and recirculation interval

The mixing and sludge recirculation interval is one of the key successes of the solid-state anaerobic digestion process, a promising technology for converting high-solid agro-industrial wastes to renewable energy. This study employed a pilot-scale completely stirred tank reactor to examine biogas production from sweet corn waste, including corn cobs, husks, and seeds. The reactor was operated as solid-state anaerobic digestion at an ambient temperature. The mixing and recirculating intervals were set to non-mixing and mixing for 10 minutes every 3, 6, and 12 hours. The initial total solid of the feedstock was 25%, while the hydraulic retention time was 30 days. The results showed that during the mixing and recirculation every three hours, the highest chemical oxygen demand, total solid, and volatile solid (VS) removal efficiencies were 85.42%, 62.92%, and 64.59%, respectively. The ratio between volatile fatty acid and alkalinity ranged between 0.20 and 0.30 without any sign of system failure. The highest specific methane yield of 766 L/kg VSadded was obtained in the experiment with mixing and recirculating intervals every 3 hours. It was found that the modified Gompertz model could effectively fit the methane yields with an R2 of 0.9667. The modeled methane production potential and the maximum methane production rate were 867.40 NL/kg VSadded and 132.01 NL/kg VSadded-d, respectively. Additionally, the levelized cost of the biogas produced from the solid-state anaerobic digestion of the sweet corn waste was calculated to be 0.61 USD/kg. The findings of this study can serve as a guide for the design and operation of the SS-AD system, which aims to transform various types of lignocellulosic waste into environmentally friendly energy.

Recognition of Heat-Damaged Corn Seeds Based on Fusion of Laser Ultrasonic Signal and Infrared Image Features

Corn is widely cultivated on a global scale. However, high temperatures during storage and transportation can lead to thermal damage to the kernels, negatively impacting their quality. Traditional methods for identifying heat-damaged grains primarily rely on manual inspection, which is characterized by low efficiency and accuracy. This study proposes a novel identification method that integrates laser ultrasonic signals with infrared image texture features. A pulsed laser stimulates the seeds to generate laser ultrasonic signals, while an infrared camera captures infrared images of the seeds. We extract time-domain, frequency-domain, and Hilbert-domain features from the laser ultrasonic signals, in addition to texture features from the infrared images. These features are combined using Canonical Correlation Analysis (CCA). Subsequently, the fused features are classified using a Backpropagation (BP) neural network, Support Vector Machine (SVM), and Particle Swarm Optimization–Support Vector Machine (PSO–SVM). The results indicate that the recognition rate achieved with the fused ‘signal-image’ features reaches 99.17%, providing a novel approach for detecting heat-damaged corn seeds.

Validation of degree day threshold for Delia platura first emergence in New York State

Seedcorn maggot (Delia platura) is a globally distributed agricultural pest that feeds on the germinating seeds of economically important crops, including corn and beans. The larvae cause underground damage, which can lead to stand loss. For decades, D. platura has been managed using insecticide-coated seeds, but following the ban on neonicotinoid-coated corn, soy, and wheat seeds in New York State, this practice will no longer be available. Degree day models have been used to predict the emergence of the overwintering generation of agricultural pests since the late 1900s. However, the terminology used in the literature to distinguish degree day thresholds for first emergence and peak emergence is unclear, and previous reports of a 360 degree day emergence threshold did not align with field observations. In 2023, we captured the first emergence at four sites, and in 2024, we monitored adult D. platura at 25 sites in New York State. We observed the first adult emergence between 52 and 197 accumulated degree days (98 ± 7 degree days, mean ± 1 SE) using a biofix of January 1st, confirming that in New York State, D. platura emergence is earlier than previously reported values. Additionally, we note adult activity during December 2023 and January 2024, suggesting that warming winters may impact our ability to predict pest emergence. We propose future models should incorporate both degree day information and other regionally specific factors known to impact pests, including farm management, soil conditions, and landscape composition, for more accurate predictions.

Design of Positive Pressure Re-Acceleration Assisted Seeding Mechanism for Corn Based on CFD-EDEM Gas-Solid Coupling Simulation

This study proposes a positive pressure re-acceleration assisted seeding mechanism and analyzes the motion mechanism of corn seeds during the seeding process. By employing the CFD-EDEM gas-solid coupling simulation analysis method, the fluid characteristics, initial ejection velocity of seeds, seed dropping time difference, and sowing position difference in the seeding mechanism under different structural parameters of the air pressure valve body were investigated. The optimal structural parameters of the air pressure valve body were determined (nozzle gap c = 0.6 mm, throat constriction diameter d = 16 mm, and throat constriction length l = 44 mm). A multi-factor experimental method was used to explore the effects of airflow pressure, forward speed during sowing, and sowing distance on sowing performance, aiming to identify the optimal working parameters for the positive pressure re-acceleration seeding mechanism. High-speed camera technology was used to record and analyze the seed movement process. The results indicate that an increase in positive pressure within the seed guide tube shortens the sowing time of corn seeds, reduces the coefficient of variation of seed dropping time difference, and effectively improves the consistency of sowing distance. The optimal parameters are a forward speed of 8 km/h, sowing distance of 20 cm, airflow pressure of 10 kPa, with a sowing distance coefficient of variation of 7.56%, and a seed dropping time difference coefficient of variation of 5.35%.

Growth Rate and Production of Hybrid and Local Maize (Zea Mays L.) in Response to Various Doses of Nitrogen Fertilization

Corn (Zea mays L.) is a strategic commodity after rice so that the productivity need to be optimize through nitrogen fertilization. The aim of this research is to evaluate the effect of various doses of urea fertilizer on the growth rate and yield of hybrid corn and local corn. This research was conducted from June to October 2022 on the pilot land of the Agricultural Training Center (Bapeltan), Hajimena, Bandar Lampung. The factorial experiment (5x2) was arranged in a randomized complete block design with 3 replications. The first factor is urea fertilizer doses, namely: 200 kg/ha (N1), 250 kg/ha (N2), 300 kg/ha (N3), 350 kg/ha (N4) and 400 kg/ha (N5), while other fertilizers were given to all experimental plots in the same rate (150 SP-36 kg/ha and 100 kg KCl kg/ha). The second factor is the corn variety, included V1 (BISI-18) and V2 (Tongkol Merah) varieties. The results showed that increasing dose of urea from 200 to 400 kg/ha was not able to increase the growth rate of both corn varieties. The productivity of the BISI-18 corn variety is higher than that of the Tongkol Merah as indicated by the wet weight of the cobs (g), the dry weight of grains per plot (g), and the yield of corn dry grains (tons/ha). The yield of dry corn seeds for the BISI-18 corn variety was 11.7 tons/ha, while for the Tongkol Merah variety was 9.44 tons/ha. Keywords: Fertilizer dosage, Hybrid corn, Local corn, Nitrogen use efficiency, Yield.

Sweet corn (Zea mays L.) seed performance enhanced under drought stress by chitosan and minerals coating.

Sweet corn (Zea mays L.) var. Saccharata is a tropical and semitropical annual cereal with low germination, poor vigor, and weak seedling establishment in the soil. In order to enhance the physical properties of sweet corn and examine the effects of seed coating on the morphological, biochemical, and physiological characteristics of sweet corn seedlings under drought stress conditions, we conducted a factorial experiment in greenhouse conditions. Seed coating was carried out using a mixture of vermiculite (V), kaolin (K), and perlite (P) in a ratio of 3:1.5:2. The main factors of the greenhouse experiment comprised three levels of coating treatment (chitosan 0.5% + V10K2.5P5 (gr), NaAlg 1% + V10K2.5P5 (gr), and non-coated seeds as a control) along with drought stress at four levels (0, -0.3, -0.6, and -0.9bar). In greenhouse conditions, the growth indexes of sweet corn seedlings were studied under increasing levels of drought stress. The results showed that as drought stress levels increased, certain growth indicators such as seedling emergence and seedling emergence rate, soluble protein, chlorophyll total content, nitrogen, and phosphorus content decreased. On the other hand, mean emergence, proline, potassium, soluble sugars, malondialdehyde, and hydrogen peroxide were increased. The study found that the highest seedling emergence percentage occurred in the coating treatment of chitosan 0.5% + V10K2.5P5 (gr) at all levels of drought stress. Overall, seed coating with the Chitosan 0.5% + V10K2.5P5 (gr) treatment improved the performance of sweet corn seeds and reduced the negative effects of drought stress by increasing seedling emergence and establishment.

Detection of Mechanical Damage in Corn Seeds Using Hyperspectral Imaging and the ResNeSt_E Deep Learning Network

Detection of Mechanical Damage in Corn Seeds Using Hyperspectral Imaging and the ResNeSt_E Deep Learning Network

Evaluation of physiological quality and vigor of corn seeds coated with chitosan

Evaluation of physiological quality and vigor of corn seeds coated with chitosan

OPTIMASI MEDIA DAN TEKNIK STERILISASI UNTUK MENINGKATKAN KUALITAS MISELIUM BIBIT F2 JAMUR TIRAM (Pleurotus ostreotus)

F2 seeds are a derivative of F1 cultivation grown in a medium containing cellulose. Sorghum seeds and corn seeds contain cellulose, hemicellulose, and lignin that can be used as innovative media for F2 seedling development and the growth of oyster mushroom mycelium. The purpose of this research is to determine the growth of F2 oyster mushroom mycelium on media of sorghum seeds and corn seeds that have been sterilized for 40 minutes and 60 minutes. The type of research used is an experiment with a Completely Randomized Design (CRD) in a factorial pattern consisting of 2 factors. Factor 1 is the media type: Sorghum Seeds, and corn Seeds. Factor 2 is the Sterilization Time: 60 minutes and 40 minutes. The parameters measured are the length of the mycelium, the spread of the mycelium, and the thickness of the mycelium in F2 oyster mushroom seedlings. Technical analysis uses quantitative descriptive data. Based on the results obtained regarding the growth of the F2 oyster mushroom mycelium, the highest growth was observed on sorghum seed media, measuring 13.81 cm, with a very thick and dense spread. The cellulose content affects the growth of the mycelium. Meanwhile, the lowest growth of the F2 oyster mushroom mycelium was found on corn seed media, measuring 11.27 cm, with a thin and uneven spread, and a density or thickness that is thin and sparse.

The Study of the Process of Supplying Seeds of Row Crops Using a Vacuum Seed-Placing Unit

Introduction. The performance of precision seeders depends on many factors, including the functionality of their dosing systems, the modernization of which is possible only on the basis of patterns, which allows forecasting the indicators of single seed placing into a furrow.Aim of the Study. The study is aimed at analyzing the influence of the diameter of the suction holes of seed-placing units and the rarefaction created in them on the characteristics of placing seeds of the main row crops.Materials and Methods. The results of the study were obtained based on a series of experiments on sowing corn and sunflower seeds using an MS-8 seeder, the operation principle of which can be considered typical for vacuum seed-placing units.Results. There have been obtained empirical dependences of the particular features of zero and group placing seeds of such row crops as corn and sunflower on the area of the suction holes and the rarefaction in the vacuum chamber.Discussion and Conclusion. The quantitative estimates obtained may differ for seeds of the same crop, but having different technological properties. The general factor is that the frequency of missing seeds is proportional to the suction force magnitude in the working plane of the metering element, regardless of its area. At the same time, the probability of double seed placing depends on the area of the metering ports with a constant suction force, a decrease in their diameter leads to a decrease in the frequency of double seed placing. The data obtained allow considering joint variations in the magnitude of the rarefaction in the vacuum chamber and the diameter of the suction holes as effective tools for improving the seed placing quality.

Interference of mechanical damage on the physiological performance of corn seeds

Corn (Zea mays L.) is cultivated and consumed globally due to its nutritional qualities and short production cycle. However, during harvesting, processing, transportation, and storage, seeds are susceptible to various types of damage that can compromise their productive capacity, affecting both germination and plant vigor. Therefore, this study aimed to evaluate the physiological quality of corn seeds subjected to different types of mechanical damage. The experiment was conducted at the Laboratory of Storage and Processing of Agricultural Products at the Federal University of Campina Grande, Campina Grande, Paraíba, Brazil. Corn seeds were subjected to four types of mechanical damage: hammering, cutting, abrasion, and perforation, alongside a control sample that did not undergo any mechanical damage. Each treatment (mechanical damage) consisted of 200 seeds, which were evaluated through germination tests, including first count, germination rate, germination speed index (GSI), seedling dry weight, and root length. The experiment was conducted in Completely Randomized Design. Data were subjected to Analysis of Variance, and means were compared using the Scott-Knott test (P ≤ 0.05) when necessary. Mechanical damage reduces the germination and vigor of corn seeds. Cutting-type damage affects corn seeds more severely, reducing germination by an average of 80% and impairing vigor.

Estimation Model for Maize Multi-Components Based on Hyperspectral Data.

Assessing the quality of corn seeds necessitates evaluating their water, fat, protein, and starch content. This study integrates hyperspectral imaging technology with chemometric analysis techniques to achieve non-invasive and rapid detection of multiple key components in corn seeds. Hyperspectral images of the embryo surface of maize seeds were collected within the wavelength range of 1100~2498 nm. Subsequently, image segmentation techniques were applied to extract the germ structure of the corn seeds as the region of interest. Seven spectral data preprocessing algorithms were employed, and the Detrending Transformation (DT) algorithm was identified as the optimal preprocessing method through comparative analysis using the Partial Least Squares Regression (PLSR) model. To reduce spectral redundancy and streamline the prediction model, three algorithms were employed for characteristic wavelength extraction: Successive Projections Algorithm (SPA), Competitive Adaptive Reweighted Sampling (CARS), and Uninformative Variable Elimination (UVE). Using the original spectra and extracted characteristic wavelengths, PLSR, BP, RBF, and LSSVM models were constructed to detect the content of four components. The analysis indicated that the CARS-LSSVM algorithm had the best prediction performance. The PSO algorithm was employed to further optimize the parameters of the LSSVM model, thereby improving the model's prediction performance. The R values for the four components in the test set were 0.9884, 0.9490, 0.9864, and 0.9687, respectively. This indicates that hyperspectral technology combined with the DT-CARS-PSO-LSSVM algorithm can effectively detect the main component content of corn seeds. This study not only provides a scientific basis for the evaluation of corn seed quality but also opens up new avenues for the development of non-destructive testing technology in related fields.

Physiological quality of green corn seeds under water stress conditions

This study aimed to evaluate the physiological quality of green corn seeds subjected to water stress. The experimental design used was completely randomized, in a 2 x 5 factorial arrangement, consisting of two corn hybrids (AG1051 and BRS3046) and five osmotic potentials (0; -0.4; -0.8; -1.2 and – 1.6 MPa) simulated with aqueous solutions of polyethylene glycol 6000 (PEG 6000), with four replications of 50 seeds per treatment, totaling 40 experimental units. The analyzed variables were: water content, germination, root protrusion, final root protrusion, germination speed index, root length and coleoptile length. There was a significant effect of the interaction between hybrid factors and osmotic potentials for all analyzed variables, except for final root protrusion, which showed an isolated effect for the two factors studied. The results obtained indicated a higher percentage of germination and initial development of green corn seedlings for green corn seeds, hybrids AG1051 and BRS3046 at the osmotic potential of 0.0 MPa. The germination and vigor of green corn seeds decrease under water stress conditions from the osmotic potential of -0.4 MPa induced by PEG 6000, inhibiting the development of normal seedlings, affecting seed viability. Hybrid AG1051 presents superior germination and vigor compared to BRS3046.

Static and dynamic influence of forces on a being threshed corncob

BACKGROUND: With the use of high-speed shooting, it was found that the corncob, getting into the gap of the threshing unit, generally, takes a position parallel to the drum axis. Let us accept that the plane of operation of the working body of the threshing drum – the beater – coincides with the generatrix of a cob. The cob changes the motion mode because of the impact of the threshing machine beater on the cob. The impact can take place in the moment when the cob even does not hit the deck cleats, so the cob gets a flying kick. AIM: Deriving the static and dynamic influence of forces on the being threshed corncob. Defining the necessary force of corn seeds breaking-off from the cob in dependence on the friction coefficient. METHODS: The value of mechanical impact of working bodies of the orienting-metering loading device and the threshing-separating device on a corn seed is limited not only by strength properties of the protecting corn cover, but by the link strength between a seed and a cob in the nose, middle and root areas. Knowledge of this mechanical-technological property helps to increase the level of variability of force impact in corncobs from the side of working bodies of the used machinery. It helps to transport the corncobs without husk, to orient them in space, to supply in small increments for the proper processing and, in addition, to thresh without causing any macro- and microdamages to the seeds. RESULTS: The seed moisture change and, consequently, the seed-to-seed friction coefficient change also influences on the ratio between the applied force P and the reacting force N. With the same load P applied to the dry and the moisty cobs, the pressure N on the dry seed is higher than on the moisty one, and seed threshing from the dry cobs is conducted with lower external forces P at free direct impact. CONCLUSION: The process of the flying kick threshing becomes more difficult with the increase of corncobs moisture due to increase of seed-to-seed friction. The flying kick threshing of corncobs stops at the seed moisture which corresponds to the friction coefficient f = 0.22. The obtained theoretical principles are confirmed experimentally.

Pseudochrobactrum asaccharolyticum mitigates arsenic induced oxidative stress of maize plant by enhancing water status and antioxidant defense system

BackgroundOxidative stress mediated by reactive oxygen species (ROS) is a common denominator in arsenic toxicity. Arsenic stress in soil affects the water absorption, decrease stomatal conductance, reduction in osmotic, and leaf water potential, which restrict water uptake and osmotic stress in plants. Arsenic-induced osmotic stress triggers the overproduction of ROS, which causes a number of germination, physiological, biochemical, and antioxidant alterations. Antioxidants with potential to reduce ROS levels ameliorate the arsenic-induced lesions. Plant growth promoting rhizobacteria (PGPR) increase the total soluble sugars and proline, which scavenging OH radicals thereby prevent the oxidative damages cause by ROS. The main objective of this study was to evaluate the potential role of Arsenic resistant PGPR in growth of maize by mitigating arsenic stress.MethodologyArsenic tolerant PGPR strain MD3 (Pseudochrobactrum asaccharolyticum) was used to dismiss the ‘As’ induced oxidative stress in maize grown at concentrations of 50 and 100 mg/kg. Previously isolated arsenic tolerant bacterial strain MD3 “Pseudochrobactrum asaccharolyticum was used for this experiment. Further, growth promoting potential of MD3 was done by germination and physio-biochemical analysis of maize seeds. Experimental units were arranged in Completely Randomized Design (CRD). A total of 6 sets of treatments viz., control, arsenic treated (50 & 100 mg/kg), bacterial inoculated (MD3), and arsenic stress plus bacterial inoculated with three replicates were used for Petri plates and pot experiments. After treating with this MD3 strain, seeds of corn were grown in pots filled with or without 50 mg/kg and 100 mg/kg sodium arsenate.ResultsThe plants under arsenic stress (100 mg/kg) decreased the osmotic potential (0.8 MPa) as compared to control indicated the osmotic stress, which caused the reduction in growth, physiological parameters, proline accumulation, alteration in antioxidant enzymes (Superoxide dismutase-SOD, catalase-CAT, peroxidase-POD), increased MDA content, and H2O2 in maize plants. As-tolerant Pseudochrobactrum asaccharolyticum improved the plant growth by reducing the oxidation stress and antioxidant enzymes by proline accumulation. PCA analysis revealed that all six treatments scattered differently across the PC1 and PC2, having 85.51% and 9.72% data variance, respectively. This indicating the efficiency of As-tolerant strains. The heatmap supported the As-tolerant strains were positively correlated with growth parameters and physiological activities of the maize plants.ConclusionThis study concluded that Pseudochrobactrum asaccharolyticum reduced the ‘As’ toxicity in maize plant through the augmentation of the antioxidant defense system. Thus, MD3 (Pseudochrobactrum asaccharolyticum) strain can be considered as bio-fertilizer.

Biopriming of corn seeds based on Bacillus subtilis under different storage periods

Corn crop (Zea mays L.) is one of the pillars of Brazilian agriculture, with a wide cultivation area and high productivity; Brazil is the world's second largest exporter of this cereal. For this reason, the aim of the present study was to evaluate the viability of biopriming of corn seeds with a product based on Bacillus subtilis, at different concentrations, up to 120 days of storage. The research was carried out in the seed technology laboratory of the State University of Londrina (UEL), using the commercial corn seeds Balu 366. The experimental design was completely randomized, with four replications, in a 7 × 5 factorial scheme, with seven concentrations of the commercial product based on Bacillus subtilis (Serenade) for seed biopriming (0.0, 2.5, 5.0, 7.5, 10.0, 12.5, and 15.0 %) and five storage periods in a cold chamber (0, 30, 60, 90, and 120 days). The evaluation of the physiological quality of the seeds occurred through germination, cold and seedling length tests. The variables analyzed were first germination count, germination percentage, vigor from the cold test, shoot length, length of the longest root, shoot dry mass, and root dry mass. For the statistical analysis, adjustments of regression models with the best fit were made. The biopriming of seeds proved to be an advantageous practice to enhance the physiological quality of the seeds under storage; it should be carried out at a concentration of 2.5 %, due to its economic viability, considering its efficiency equivalent to the highest concentrations. The biopriming of seeds proved to be a viable practice for seed storage for up to 60 days.

Síntesis y caracterización de partículas poliméricas yodadas submicrométricas con efecto bioestimulante en la germinación y vigor de plántulas de maíz

Current agriculture faces challenges caused by climate change, which induce states of stress in plants, reducing crop productivity. Micro- or nanomaterials are biostimulants that mitigate these adverse effects, having greater efficiency compared to conventional materials. Iodine, at low concentrations, improves plant growth and production. This study aimed to: 1) synthesize and characterize polymeric particles functionalized with submicron iodine (PI), 2) evaluate the impact of pretreatment of corn seeds with these particles on the germination rate and growth of the seedlings, and 3) quantify the iodine in the PI and in the seedlings. The synthesis of the PI was carried out by a chemical reaction from iohexol with a crosslinker and the addition of a polyethylene glycol coating. The average hydrodynamic diameter of the PIs determined by dynamic light scattering was 217 nm, and the iodine content in the synthesized PIs was 1.67 %. For the germination test, four PI concentrations (5, 10, 20, and 50 mg∙L<sup>-1</sup>) and a control (distilled water) were used; 50 seeds were imbibed in 10 mL of each solution and placed in a growth chamber at a temperature of 28 °C for 24 h. The results indicate that PIs do not negatively interfere with the seed germination process and the treatment with a concentration of 50 mg∙L<sup>-1</sup> PI significantly favored some growth variables. The latter indicates that the synthesized PIs presented a biostimulant effect and may be a viable alternative as a biofortifier.

RESPON PERTUMBUHAN DAN PRODUKSI TANAMAN JAGUNG PULUT TERHADAP PERLAKUAN PRUNING TONGKOL KEDUA DAN PENYEMPROTAN PUPUK PELENGKAP CAIR

This study was conducted to determine the response of corn plants to the second cob pruning treatment and liquid complementary fertilizer (LCF) spraying on the Growth and Production of Waxy Corn Plants (Zea mays ceratina L.). This study was conducted at the Experimental Garden of Pabentengan Bajeng Village, Gowa Regency, South Sulawesi, from September to December 2018. The materials used in this study were local waxy corn seeds, liquid complementary fertilizer (Bram Evolution) urea and NPK fertilizer. The Split Plot Design method was used. The main plot is without pruning and with pruning, while the sub-plot is Spraying Liquid Complementary Fertilizer (LCF) consisting of 4 levels, namely without LCF spraying, spraying with a concentration of 10 mL/L water, 20 mL/L water, and 30 mL/L water, 8 treatment combinations repeated 3 times to obtain 24 experimental units. The results of this study indicate that pruning the second cob increases the dry weight of the plant, seed weight per plant, seed weight per plot, and seed weight per hectare. LCF spraying and the interaction between pruning and LCF spraying treatments did not affect the observed parameters

Effects of methyl jasmonate seed treatments on adult oviposition preference and larval performance of seed corn maggot (Delia platura) in corn (Zea mays).

Eliciting host plant resistance using plant hormones such as jasmonates has the potential to protect seeds and seedlings against insect pests; however, several hurdles exist for adapting it for pest management. This includes determining a dose that promotes resistance without limiting plant growth, an application method that growers could use, and ensuring the plants are responsive in the abiotic conditions when the pest occurs. In laboratory and field assays, we tested if treating corn seeds with multiple concentrations of methyl jasmonate would reduce the preference of ovipositing seed corn maggot adults and the performance of larvae feeding on seeds. We found that corn seeds soaked in aqueous 0.2 mM methyl jasmonate solution showed marginally lower seedling growth, but the adult oviposition preference was ~60% lower on these seeds compared to control water-soaked seeds. Seeds that were treated with methyl jasmonate using a conventional polymer-based seed coating showed no effect on seedling growth but reduced adult oviposition preference. In no-choice bioassays with adult flies, we found reduced oviposition on seeds soaked with aqueous methyl jasmonate compared to controls. Larval survival to pupation was also lower in methyl jasmonate-treated seeds. Lastly, the methyl jasmonate-induced resistance also occurred at the lower temperatures typical of the spring soil conditions when this fly is most damaging. Methyl jasmonate seed treatment in aqueous solution or using conventional polymer-based technology, has the potential to deter adult oviposition and reduce maggot performance in spring temperature conditions with minor effects on seed germination and growth. © 2024 Society of Chemical Industry.