Maize Threshing and Separating Device for Primary Seed Production

Worldwide Maize (Zea mays L.) is referred to as the “Miracle Crop” due to its high genetic yield potential compared to other Gramineae family members. Hybridization plays a vital role in boosting the production and productivity of maize, which is crucial for mitigating food insecurity in developing countries. To find out the best hybrid among the maize hybrids, a field experiment was conducted during the kharif season of 2021 at the experimental field of the Crop Research Farm, Department of Agronomy, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh, India. The study was conducted for “Evaluation of Maize (Zea mays L.) hybrids under agro-climatic conditions of Prayagraj, Uttar Pradesh”. The experiment was done on 10 maize Hybrids. It was carried out in Randomized Block Design (RBD) with three replications. The report of the study indicates that among different maize Hybrids, UM-12 produced significantly higher plant height (217.05 cm), number of leaves per plant (12.80), dry weight per plant (151.25 g), cob length (16.62 cm), number of rows per cob (14.80), number of grains per row (31.73), seed yield (8.27 t/ha) and stover yield (20.50 t/ha). Hence, it can be concluded that the Maize hybrid UM-12 was found to be the most suitable, productive and economical for the agroclimatic conditions of Prayagraj, Uttar Pradesh.

Seed companies have commercialized new transgenic maize (Zea mays L.) hybrids that are resistant to European corn borer [Ostrinia nubilalis (Hübner)]. Drought stress may affect the expression of Bt proteins in maize tissues, and its resistance to European corn borer (ECB). This study was conducted at the Iowa State University Hinds Irrigation Farm, Ames, IA, to characterize the effect of drought stress on Bt maize. Growth and development measurements were taken in 1997 and 1998 from Bt and non‐Bt maize plants subjected to various soil water deficit treatments during peak ECB egg laying periods (late June, first generation; late July, second generation) on maize plants grown in buried, 1 m deep, 123‐L containers filled with Nicollet loam soil (fine‐loamy, mixed, superactive, mesic Aquic Hapludolls). Water deficit delayed leaf appearance up to 6 d, depending on leaf number and tasseling up to 3 d. It also reduced leaf area as much as 33% and plant height by 15%, depending on leaf number and timing of water deficit. For these characteristics, there was no significant difference between Bt and non‐Bt maize plants. There were significant differences among Bt and non‐Bt plants for second generation corn borer damage with Bt plants affected the least. This resulted in significant yield differences between Bt and non‐Bt plants. Compared with non‐Bt plants, Bt plants exhibited significantly greater total plant weight in 1997 (9.7%) and grain yield in 1998 (9.4%). These differences depended on variety and seemed related to 100‐seed weights.

Drought‐tolerant (DT) maize ( Zea mays L.) hybrids have demonstrated better performance than non‐DT hybrids when drought events are present. The objective of this study was to assess the performance of three DT maize hybrids for whole‐plant dry matter (DM) and grain yield and forage nutritive value under conventional or Kura clover ( Trifolium ambiguum M. Bieb.) perennial groundcover (PGC) cropping systems. This study was conducted for 3 years at two locations, Arlington and Lancaster, WI. Three DT and one non‐DT maize hybrid were no‐till sown into killed Kura clover (conventional) and living Kura clover that was suppressed with herbicides (PGC). Whole‐plant maize, as for silage, was harvested at 50% kernel milk line, and grain was harvested at physiological maturity. Whole‐plant biomass was analyzed for forage nutritive value. There was no cropping system × maize hybrid interaction for any of the measured yield or nutritive value parameters. Maize hybrids in the Kura clover PGC system yielded 3.0 Mg ha −1 less whole‐plant DM and 1.5 Mg ha −1 less grain than in the conventional system, but whole‐plant forage digestibility was slightly greater with the PGC system. DT hybrids yielded slightly less than the non‐DT hybrid over both production systems. The DT hybrids demonstrated no advantage relative to a non‐DT maize hybrid in a Kura clover PCG system.

Changes in DNA and in nuclear and nucleolar dry mass and area in senescing parenchyma cells of corn cob and stalk tissues

Maize (Zea mays L.) is an important cereal adversely affected by drought stress. Screening the germplasm of maize crop is prerequisite to categorize the genotypes based on drought tolerance and sensitivity. With the objective to sort out the contrasting genotypes, eight maize varieties (V1=FH-988, V2=20R52, V3=FH-1046, V4=Rustam-1, V5=FH-949, V6=Pioneer30Y87, V7=FH-1137, and V8=Rustam-12) were grown under well-watered (WW= 0 MPa) and water stressed (DD = -0.60MPa) conditions. Drought was estimated by applying PEG-8000. Plants were harvested four weeks after transplanting and the evaluation was done on the basis of various morphological (root length, shoot length, root fresh weight, shoot fresh weight, root dry weight, shoot dry weight, root shoot ratio, number of leaves) and biochemical parameters (potassium and chlorophyll contents in leaves). Relative leaf water contents and membrane stability index were also measured. The data collected was analyzed statistically at 1% probability level and Least Significant Difference Test (LSD) was applied to separate the significant treatment means. The results showed that the water stress adversely affected on the morphological parameters. The maize hybrid FH-988 had significantly higher (p<0.01) morphological and biochemical parameters and found more drought tolerant. While maize hybrid FH-1137 had lower these parameters as compared to all other maize hybrids and was considered as drought sensitive genotype. Study findings showed that the screening of drought tolerant genotypes could be a better source to mitigate the drought stress impacts on maize in drought prone regions. Keywords: Drought tolerant; Hydroponic; Maize; Water stress http://dx.doi.org/10.19045/bspab.2019.80002

Maize hybrids react differently to various plant density and intra-row spacing. A two-year study was conducted at Mustafa Kemal University, Agricultural Faculty, Research Farm to determine the optimum intra-row spacing for maize hybrids commercially grown in Eastern Mediterranean Region during 2000 and 2001 growing seasons. The experimental design was a Randomized Complete Block in a split-plot arrangement with three replications. Main plots were maize hybrids of Dracma, Pioneer 3223, Pioneer 3335, Dekalb 711 and Dekalb 626. Split-plots were intra-row spacing of 10.0, 12.5, 15.0, 17.5 and 20.0 cm. Split-plot size was 2.8 by 5.0 m with four rows per plot. The effects of intra-row spacings on the grain yield and some agronomic characteristics were statistically significant. Hybrid x intra-row spacing interaction effects were significant only at ear length and grain yield. The highest grain yields were obtained from Pioneer 3223 and Dracma at 15.0 cm intra-row spacing (11718 and 11180 kg ha-1, respectively).

Maize is an important cereal crop of the world and in India, it is grown in the rainy and post-rainy seasons. In the rainy season, among other stresses affecting the maize productivity, drought is significant under a changed climatic scenario. Although maize is sensitive to drought at all growth stages, drought at the seedling stage results in a poor crop stand and establishment, significantly impacting productivity. Identifying moisture-stress tolerant maize inbred lines for seedling stage drought situations and using those in developing drought-tolerant hybrids play a pivotal role in increasing maize yield. In this study, a set of hybrids derived from tolerant and susceptible inbreds was studied for their response under in vitro seedling drought induced by polyethylene glycol, employing the slanting plate technique. Substantial variability among different polyethylene glycol levels (0, 10 and 20 %), maize hybrids and interaction between polyethylene glycol levels and maize hybrids was observed for germination and seedling traits, indicating differential response of the maize hybrids. Higher genetic advance with higher heritability was observed for root and shoot length, indicating the preponderance of additive gene action governing these traits. It was interesting to note that the germination ability of seeds was significantly reduced in all hybrids at 20 % polyethylene glycol, following poor seedling vigour that was reflected in diminished expression of seedling traits. The hybrids, GPM 114 × CML 451 and GPM 114 × CAL 1426-2, involving seedling drought-tolerant parents, showed lesser reduction for root length, suggesting these drought-tolerant lines can be used as donors for the development of seedling drought-tolerant hybrids suitable for cultivation in rainfed eco-systems. It is evident from the present study that screening maize genotypes at 20 % polyethylene glycol would help in identifying reliable genotypes for seedling drought tolerance.

Background and Aims Root-derived carbon (C) inputs are increasingly recognized as important precursors to soil organic carbon (SOC). However, the extent to which these inputs can be influenced by nitrogen (N) fertilizer management and plant stature remains poorly understood. This study investigated how N fertilization rate and maize hybrid stature trade off between above- and belowground performance, including investment in root traits, exudation, and soil microbial C pools. Methods Tall- and short-stature maize (Zea mays) hybrids, from Bayer’s breeding pipeline, were grown in a pot experiment in two soil matrices (sandy and loamy), with N fertilization rates of 0, 90, 180, and 270 kg N ha⁻ 1 . C pools in above- and belowground compartments were assessed, including root exudates, root biomass and length, soil microbial biomass C, and total soil C. Results Soil matrix and maize hybrids of different stature primarily explained differences in root exudation and belowground C inputs. Short-stature maize produced 22% greater dry root biomass than tall maize across N treatments. Loamy soils accumulated higher soil microbial biomass C and peaked at intermediate N rates, where fertilization achieved the greatest response in root biomass and C inputs. The highest N rates resulted in lower belowground C investment (particularly &gt; 180 kg N ha⁻ 1 in loamy soil). Conclusion Maize hybrid selection and N fertilization interaction influenced root-derived C inputs and soil microbial biomass, with short-stature hybrids and moderate N rates enhancing belowground C allocation. These findings suggest that short-stature maize and avoiding excessive N fertilizer rates can enhance root contributions to key soil C pools.

Several maize (Zea mays L.) hybrids have been developed and commercialized in the Nigeria savannas, but limited informationis available on how they perform at plant densities higher than the recommended density of 53,333 plants ha-1. Therefore, field trials were conducted in northern Nigeria in 2015 and 2016 at two locations with contrasting rainfall amount to evaluate the performance of selected maize hybrids at plant densities of 53,333 and 88,888 plants ha-1. All maize hybrids had higher grain yields, total dry matter, ears m-2, and number of grains m-2 at 88,888 than at 53,333 plants ha-1 at both locations. The magnitude ofincreases in yield when plant density was increased to 88,888 plants ha-1 was, however, higher for the new hybrids than for the old commercial hybrids. In Tudun Wada, five hybrids produced significantly higher mean grain yields than the remaining hybrid sat both plant densities. One of the hybrids (M1227-12) produced the highest grain yield at both planting densities at this location. In Samaru Zaria, the hybrid M1227-12 produced the highest grain yield only at 53,333 plants ha-1 at this location, whereas M0926-8 produced the highest yield at 88,888 plants ha-1. The 500-grain weight was 7-8% lower at 88,888 plants ha-1 than at 53,333 plantsha-1, which was offset by a significant increase in grain number. Our results showed that farmers in the Nigeria savannas can increase planting density of hybrid maize to 88,888 plants ha-1 and significantly increase their yields.

The analysis of existing methods of air classification of crushed bulk materials is carried out, priority directions of their development and improvement are identified, the hardware design of these methods and the main approaches to the calculation of air classifiers are studied. The conclusion is made about a rather isolated motion of particles in the working volume of the classifier at optimal performance. The prospects of dry separation methods and the progressiveness of creating multistage gravitational classifiers have been established. Theoretical studies of the separation process in a gravity classifier with overflow shelves have been carried out. The regularities of the process of separation of bulk materials in air classifiers have been established, reliable methods have been developed for calculating their technological and design parameters in order to create highly efficient and productive industrial plants. Theoretical dependencies and differential equations are obtained, which characterize the influence on the separation mechanism of technological and design parameters of the classifier. The results of solving the equations of motion made it possible to determine the main design parameters of the apparatus based on the technological requirements for productivity and the dispersed composition of the final products. On the basis of theoretical research, analytical relationships and differential equations have been developed that describe the separation process in a gravity classifier with overflow shelves. The use of these equations made it possible to simulate the air flow in the classifier, to obtain a field of air flow velocities for any design and technological parameters. This, in turn, shows the direction of movement of particles of different sizes or densities and makes it possible to estimate the boundary size of separation, and also allows you to study the interaction of the air flow with the material being separated in a wide range of technological and design parameters of the classifier, and, ultimately, to determine the boundary size separation and particle size range of the resulting fractions of the finished product. The relationship between technological and design parameters of the apparatus is theoretically determined.

Due to the energy crisis, special attention is paid to the production and use of biofuels. After-harvesting residues of corn (AHRC) may become a perspective source of energy for grain dryers. The following components of the AHRC are distinguished: stem, leaves, rod and wrapper of the cob. The AHRC is about 55...60% of the total weight of the plant. The annual harvest of corn grain is more than 20 million tons. The calorific value at burning of wheat straw is 14.4 MJ/kg, AHRC -15.7 MJ/kg. For comparison, the calorific value of wood on average is 14.24 MJ/kg, and natural gas is 33.5 MJ/m3 [1]. Using the AHRC can significantly reduce the need for imported gas. One of the directions of the use of plant raw materials as fuel is the production of granules [2]. The technology involves purifying raw materials from impurities, crushing and granulation. For a similar scheme, granulated feeds are produced. When picking up a harvester, following transportation and reloading, various contaminants, including mineral impurities in the form of stones, fall into the green mass. Having hit the crusher stones lead to damage to parts of the crushing mechanism, an accident and even an explosion. Clearing straw from impurities in agriculture is carried out on pneumatic separating machines [3]. But in the technical literature there is no data available to the separation of mineral impurities from the AHRC. As a result of the experiments, it was found that leaves and stalks can be separated by air from large stones, and the separation ofrods from stones is complicated. Under the influence of air flow, the rods are rotated along the pneumatic separating canal and unfolded by a long axis in parallel with the air flow, which leads to a decrease in the area of the midel section and to the reduction of the aerodynamic resistance. Therefore, to provide the required force acting on the core from the air stream, they increase the air velocity, which causes the capture and joint movement of the stones. To improve the separation process of the AHRC from the stones, it is necessary to develop a nutritional mechanism of the separator, in which to predict the possibility of orientation of the rods in the pneumocaps to the long axis across the air flow. This will enable you to reduce the air velocity required for separation and increase the difference in aerodynamic forces acting on the stones and rods. Accordingly, at the same time, the energy intensity of the pneumatic separation process will decrease and the efficiency of separating the AHRC from the stones increases. The separation of small stones smaller than 3 mm only by air is impossible, since they are picked up by the air flow that moves at the speed necessary for separating the stems (7.5...12.5 m/s). For the separation of small stones, it is proposed to use grid separators with combined air purge. For the complete separation of mineral impurities from corn cores, it is recommended to use hydro-separators.

Heavy metals are contaminants of much environmental apprehension, as they are hazardous to human being and other biota. The chelates react with the heavy metals and free that metal from the cation exchange sites and resulting the metal chelated species and move readily into the soil. For this purpose, a hydroponic stud was conducted in wire house of Saline Agricultural Research Center to monitor the potential of Maize (Zea mays L.) cultivars against cadmium (Cd) and lead (Pb) toxicity. A chelated source Ethylene Diamine Tetra Acetic acid (EDTA) was used to evaluate the uptake of Cd and Pb. The experiment was comprised of nine treatments. As T1= Control, T2= Cd 25 ppm, T3= Pb 50 ppm, T4= Cd 50 ppm, T5= Pb 100 ppm, T6= Cd 25 ppm+EDTA, T7= Cd 50 ppm+EDTA, T8= Pb 50 ppm+EDTA and T9= Pb 100 ppm+EDTA. Two maize cultivars Syngenta-8711 and 33H-25 were used. It was concluded that the parameters like shoot fresh and dry weight, chlorophyll content (SPAD value) and relative water content decreased under toxic level of Cadmium (Cd) and Lead (Pb). The addition of EDTA increased the uptake of Cd and Pb which ultimately reduced the overall the plant growth. Among the maize hybrids, maximum Cd concentration was observed in Syngenta-33-H-25 while minimum in Syngenta-8711 at all cadmium stress levels. At all the lead stress levels the maximum Pb concentration was observed in Syngenta-33-H-25. The minimum Pb concentration was recorded in Syngenta-8711 at all lead stress levels. Keywords: Cadmium; Chelated; Chlorophyll content; Lead; Maize http://dx.doi.org/10.19045/bspab.2020.90206

One of the main barriers to the production of hybrid maize seeds consists of needing detasseling of female parent in order to avoid contamination with unwanted pollen. This activity is a laborious practice, which makes the production more expensive and promotes productive losses. Thus, the use of cytoplasmic genetic male sterility can facilitate the hybridization process, and consequently, the production of hybrid seeds. The objective of this study was compare grain yield in maize hybrids produced from the combination of two testers with five distinct lines of cytoplasm C “Charrua” versus the isogenic of fertile cytoplasm. Twenty common hybrids were evaluated in relation to grain crops and resistance to leaf diseases, white spot and gray leaf spot. The experiments were carried out during summer season of 2015/2016 and winter season of 2016. The use of lines with cytoplasm C was observed and it is promising since it did not affect the agronomic performance of hybrids, regardless of environment, crop season, parental and tester used. Therefore, cytoplasm C can be used as an excellent source of cytoplasmic genetic sterility in the production of hybrid seeds in seed companies that want to decrease the use of detasseling practice. Key words: Zea mays L, production of seeds, detasseling.

The aim of this research is to know effect of adding a corn cobs after fermentation in soil on the growth and development of root part of zea mays in soil columns having two soils differ in their texture, one was sandy and the other was silt clay. The soil was put in plastic pots and five zea mays seeds were added in each pot and after seed growth, one plant was left in each pot. Weight of vegetative growth and dry roots. The interval between measured and the other was fifteen days. The result showed that in the soil treated with the conditioner the percentage of pores increased while the values of bulk density and resistance to penetration decreased that reflected on the vegetative and root growth of zea mays plant, it was 175.16 g the end growth season in the soil columu and 170.11 g in the soil columu in the weight of vegetative growth, while the dry weight of root (28.74, 27.32) g in each pot respectively. Comparing with soil columus treated with the conditioner, there was un similar increase. It was (183.82, 195.65) g in dry vegetative growth and (31.75, 35.27) g/ pot as dry root growth respectively. It may be said that there was clear effected of addition of corn cobs as a conditioner of root growth followed by positive vegetative growth during growth season which may be reflected yield of zea mays.

Maize (Zea mays L.) is the third most cultivated cereal crop in the world after wheat and rice. Soil calcareousness is the key growth limiting factor causing a substantial decline in plant growth and yield in many arid and semiarid regions globally. This study aimed to understand the variability in morphological and physiological traits among maize hybrids as well as their iron (Fe) efficiency on calcareous soils. Five ruling maize hybrids [COH (M) 6, COH (M) 7, COH (M) 8, COH (M) 9 and COH (M) 10] and their six inbreds [UMI 1200, UMI 1201, UMI 1205, UMI 1210, UMI 1220, and UMI 1230] were evaluated on three calcareous soils having various free CaCO3 content (6.23 to 17.3%) with and without Fe supply. The experiment was carried out in the greenhouse of the Department of Soil Science, Tamil Nadu Agricultural University, Coimbatore, in 2019. Soil calcareousness reduced the morphological and photosynthetic parameters of all the maize hybrids, and the reduction was more in highly calcareous soils (17.3%). Significant variation in Fe efficiency among maize hybrids was observed and shows good association with physiological and photosynthetic characteristics. The maize hybrids COH (M) 6, COH (M) 8, and COH (M) 7 record higher growth attributes, photosynthetic parameters, and active Fe content with better Fe efficiency. Lower Fe efficiency was noted with inbreds UMI 1230 and UMI 1220. The study showed that maize hybrids and their inbreds were sensitive to higher soil calcareousness, but the magnitude of differences varied with genotypes.