Maize Research Articles

Potential of cattle urine as an alternative fertilizer for maize (Zea mays L.) production in Ethiopia

Maize productivity has been increasing through the years due to increased use of inorganic fertilizers. However, the price and environmental impact has brought lack of interest among the farmers. Thus, this study was aimed at evaluating the growth, yield and nitrogen use efficiency (NUE) of maize varieties under cattle urine application. The field experiment was conducted in randomized complete block design with three replications. The experiment consisted of four treatments viz. control, 100 and 50 % cattle urine and recommended dose of inorganic fertilizer. The results demonstrated a comparable growth and grain yield increment due to 100 % cattle urine and recommended dose of inorganic fertilizer. The difference between the two varieties in growth, yield and related traits, and NUE indices due to fertilizer applications was insignificant. The leaf area of maize nourished with 100, 50 % cattle urine and recommended dose of inorganic fertilizer increased by 11.15, 9.73 and 9.78 folds, respectively, in two months period relative to the controls. Fertilized plants had significantly (p < 0.05) higher grain yield (GY). The use of 100, 50 % cattle urine and inorganic fertilizers resulted in 526.76, 326.12, 542.91 % and 47.83, 36.03, 49.78 % increment in average GY and aboveground biomass, respectively, compared to controls. Similarly, plants fertilized with 50 % cattle urine showed an average GY reduction of 39.87 and 38.10 % compared to the recommended dose of inorganic fertilizer and 100 % cattle urine, respectively. The use of 50 % cattle urine produced significantly higher NUE, N agronomic efficiency (NAE), N recovery efficiency (NRE) and internal efficiency (IE). Higher GY kg-1 of N applied was obtained from cattle urine applications. In a nutshell, the results confirmed the potential of cattle urine as an alternative to inorganic fertilizers in maize production. However, further studies on optimization of the cattle urine rate and scale up works are recommended.

Evaluation of the Effect of Funneliformis mosseae Inoculation on Agronomic Parameters of Maize (Zea mays L.) under a Substrate Subjected to Gold Mining

Aim: Evaluate, in a greenhouse, the effect of the AMF, Funneliformis mosseae, on the agronomic performance of maize grown on soil degraded by gold mining. Study Design: Completely Randomized Design (CRD) with six replications. Place and Duration of Study: University of Lomé, between September 2022 and January 2023. Methodology: The experiment utilized four treatment levels - pure mineral fertilizers (To), pure AMF (Funneliformis mosseae) (T1), the combination of AMF and mineral fertilizers (T2) and a control (Co) – employing a Completely Randomized Design (CRD) with six replications. A pot of 5 liters capacity having received 5 kg of soil substrat (washed gold-bearing soil or soil taken under natural vegetation) composed the experimental unit. The experimental data were collected and analyzed. Results: gold-bearing soils are sandy and poor in organic and mineral compounds compared to soils under natural vegetation. The mycorrhization parameters do not take soil type into account. On average, 73.62 % of plants in simple inoculation were mycorrhized where as 33.43 % of plants were mycorrhized in inoculation with a synthetic fertilizer (NPK+Urea) at 60 days after sowing. The respective mycorrhization intensities corresponding to these mycorrhization rates are 41.43 and 45.67 % for the same period. The inoculation with AMF affect positively the growth, development and the productivity of maize compared to the control. Conclusion: Results suggest that Funneliformis mosseae can be used as a biofertilizer on gold mining soils in Togo for sustainable maize production.

Unraveling the Genetic Mechanisms of Maize Ear Diameter Heterosis

Hybridization has long been a crucial strategy for breeders aiming to develop high-yield crops vital for global food security. However, the exact molecular mechanisms driving heterosis (hybrid vigor) remain a topic of debate. Maize (Zea mays), which demonstrates pronounced heterosis, serves as an ideal model for studying this phenomenon. In our study, we carefully measured phenotypic changes in ear diameter, tracing its development from the inflorescence meristem (IM) to the floral meristem (FM) stages. Our findings revealed a complex progression: the hybrid's ear diameter followed an additive pattern during the IM and spikelet pair meristem (SPM) stages, shifted to incomplete dominance at the spikelet meristem (SM) stage, and ultimately displayed over-dominance at the FM stage. Notably, significant phenotypic changes occurred during the SM stage with gene expression primarily showing non-additive patterns. Gene Ontology (GO) enrichment analysis highlighted the role of cell redox homeostasis genes, which exhibited over-dominant expression in hybrids, as key contributors to heterosis. Furthermore, we identified a distinct gene expression category - dominant maternal or paternal gene expression in F1 hybrids (DMP) - characterized by exclusive expression in the hybrid and one parent, while remaining inactive in the other. This category of DMP genes plays a pivotal role in shaping the diverse gene expression patterns observed in hybrids, distinguishing them from their parental lines. In conclusion, the widespread occurrence of non-additive expression seems to enhance the efficiency of biological processes and energy distribution in hybrids, ultimately driving the manifestation of heterosis.

ZmbZIP27 regulates nitrogen-mediated leaf angle by modulating lignin deposition in maize

In grain crops such as maize (Zea mays), leaf angle (LA) is a key agronomic trait affecting light interception and thus planting density and yield. Nitrogen (N) affects LA in plants, but we lack a good understanding of how N regulates LA. Here, we report that N deficiency enhanced lignin deposition in the ligular region of maize seedlings. In situ hybridization showed that the bZIP transcription factor gene ZmbZIP27 is mainly expressed in the phloem of maize vascular bundles. Under N-sufficient conditions, transgenic maize overexpressing ZmbZIP27 showed significantly smaller LA compared with wild type (WT). By contrast, zmbzip27ems mutant showed larger LA under both N-deficient and N-sufficient conditions compared with WT. Overexpression of ZmbZIP27 enhanced lignin deposition in the ligular region of maize in the field. We further demonstrated that ZmbZIP27 could directly bind the promoters of the microRNA genes ZmMIR528a and ZmMIR528b and negatively regulate the expression levels of ZmmiR528. ZmmiR528 knockdown transgenic maize displayed erect architecture in the field by increasing lignin content in the ligular region of maize. Taken together, these results indicate that ZmbZIP27 regulates N-mediated LA size by regulating the expression of ZmmiR528 and modulating lignin deposition in maize.

Influence of briquettes and nano urea formulations on growth, yield and physiological growth indices of sweet corn (Zea mays saccharata L.)

Influence of briquettes and nano urea formulations on growth, yield and physiological growth indices of sweet corn (Zea mays saccharata L.)

Screening the carotenoid in vitro bioaccessibility of purple corn breakfast cereal consumed with milk and plant-based milk

Chronic non-communicable diseases (NCDs), such as cardiovascular diseases, diabetes, and cancer, dominate global mortality, besides compromising the quality of life. Unhealthy habits like sedentary lifestyles and poor diets escalate NCD risks. Conversely, the consumption of phenolic compounds and carotenoids has shown promise in reducing NCD risks. The food industry responds by adapting products to meet demands for healthier options rich in bioactive compounds. For instance, breakfast cereals made from purple and yellow corn offer carotenoids and anthocyanins and form a nutrient-balanced meal when consumed with milk or alternatives. However, bioactive compounds in food do not guarantee absorption, necessitating bioaccessibility studies. In this study, we aimed to evaluate the bioaccessibility of the major carotenoids in two breakfast cereals, one made with 100 % yellow corn and the other with 50 % purple corn, co-digested with whole milk, semi-skimmed milk, skimmed milk, and almond “milk”. The bioaccessibility of lutein in the breakfast cereals was evaluated using the INFOGEST 2.0 in vitro digestion method. Results showed that lutein bioaccessibility ranged from 9 % to 29 %. The bioaccessibility was lower than that observed in other food matrices, such as spinach and maize products. High fiber, low carotenoid contents, and anthocyanin presence negatively influenced the carotenoid bioaccessibility. Interestingly, the varying lipid content of milk showed no impact on lutein bioaccessibility under the examined conditions. In conclusion, the effects of lipids in a low range (0–7 %) are not significant (p > 0.05) compared to other matrix components. When developing new products with health and nutritional benefits, it is important to consider that while fiber can reduce the bioaccessibility of carotenoids, it remains crucial for gut health.

Time-course transcriptomic analysis reveals transcription factors involved in modulating nitrogen sensibility in maize

Nitrogen (N) serves both as a vital macronutrient and a signaling molecule for plants. Unveiling key regulators involved in N metabolism helps dissect the mechanisms underlying N metabolism, which is essential for developing maize with high N use efficiency. Two maize lines, B73 and Ki11, show differential chlorate and low-N tolerance. Time-course transcriptomic analysis reveals that the expression of NUGs in B73 and Ki11 have distinct responsive patterns to nitrate variation. By the coexpression networks, significant differences in the number of N response modules and regulatory networks of transcription factors (TFs) are revealed between B73 and Ki11. There are 23 unique TFs in B73 and 41 unique TFs in Ki11. MADS26 is a unique TF in the B73 N response network, with different expression level and N response pattern in B73 and Ki11. Overexpression of MADS26 enhances the sensitivity to chlorate and the utilization of nitrate in maize, at least partially explaining the differential chlorate tolerance and Low-N sensitivity between B73 and Ki11. The findings in this work provide unique insights and promising candidates for maize breeding to reduce unnecessary N overuse.

Effect of Replacing Corn Grain and Soybean Meal with Field Peas at Different Levels on Feed Intake, Milk Production, and Metabolism in Dairy Cows under a Restrictive Grazing.

This study assessed the effects of replacing soybean meal (SBM) and corn grain with field peas in the concentrate of grazing dairy cows on milk production, intake, ruminal fermentation, and blood indicators. Twelve multiparous lactating Holstein-Friesian cows were utilized in a replicated 3 × 3 Latin square design, comprising three periods and three treatments: (1) Pea-0 (Control diet): 6 kg dry matter (DM) of fresh pasture, 7.2 kg DM of grass silage, and 7 kg DM of a concentrate containing 0% pea; (2) Pea-30: Control diet with the concentrate composed of 30% pea; (3) Pea-60: Control diet with the concentrate composed of 60% pea. The effect of treatments on productive and metabolic parameters was evaluated using linear-mixed models. Pasture and total DM intake, milk production, and composition were unaffected by treatments. Despite the concentrates being isonitrogenous and isoenergetic, crude protein (CP) intake was slightly higher in Pea-30 and significantly higher in Pea-60 due to higher pasture CP content in the pasture grazed by these groups, leading to higher milk urea content, though within recommended ranges. Blood parameters showed no significant changes, except for plasma β-hydroxybutyrate, which was lowest in the Pea-60 treatment; however, all values were within ranges not indicative of subclinical ketosis. Ruminal fermentation parameters were similar across treatments. These findings support the use of field peas as a viable alternative to replace SBM and corn grain in concentrates, enabling similar milk production and composition in grazing dairy cows.

Protective Effects of Purple Corn (Zea mays L.) Byproduct Extract on Blue Light-Induced Retinal Damage in A2E-Accumulated ARPE-19 Cells.

This study investigated the antioxidative characteristics of Zea mays L. purple corn cob and husk extract (PCHE) and its potential protective effects against blue light (BL)-induced damage in N-retinylidene-N-retinylethanolamine (A2E)-accumulated ARPE-19 retinal pigment epithelial cells. PCHE had a 2,2-diphenyl-1-picrylhydrazyl radical-scavenging capacity and Trolox equivalent antioxidant capacity of 1.28±0.43 mM Trolox equivalents (TE)/g and 2,545.41±34.13 mM TE/g, respectively. Total content of anthocyanins, polyphenols, and flavonoids in the PCHE was 11.13±0.10 mg cyanidin-3-glucoside equivalents/100 g, 227.90±7.38 mg gallic acid equivalents/g, and 117.75±2.46 mg catechin equivalents/g, respectively. PCHE suppressed the accumulation of A2E and the photooxidation caused by BL in a dose-dependent manner. After initial treatment with 25 µM/mL A2E and BL, ARPE-19 cells showed increased cell viability following additional treatment with 15 µg/mL PCHE while the expression of the p62 sequestosome 1 decreased, whereas that of heme oxygenase-1 protein increased compared with that in cells without PCHE treatment. This suggests that PCHE may slow the autophagy induced by BL exposure in A2E-accumulated retinal cells and protect them against oxidative stress.

Women's Knowledge of Local Plants and Their Gastronomic Heritage in Chitral, NW Pakistan.

Women are the "guardians of the kitchen" and central to household food security, yet their role has never been studied across the Hindukush region or Pamiri Knot. This study explores the women's knowledge (specifically from the Khowar (Kho) and Wakhi linguistic groups) of local food systems and determines their role in ensuring household food security and sustainability in the mountain regions of northern Pakistan. Based on in-depth semi-structured interviews with female informants in the Rech and Broghil valleys of upper Chitral, 91 different types of food products were recorded, including wild and cultivated species. Eremurus stenophyllus and Allium barsczewskii were the commonly utilized plant species, though distinct preferences between the Kho and Wakhi groups were noted. Prominent differences were perceived in using certain cultivated plants among the two ethnic groups. For instance, Kho preferred plants like Beta vulgaris, Zea mays, and Brassica napus as indicated by the use reports, while Wakhi concentrated on Thymus serpyllum, Zygophyllum obliquum and Papaver involucratum. Both groups had shared dairy practices, but cottage cheese and curd were highly cited among Kho, while double-fermented curd and Qurut for Wakhi. The study recorded some new food uses for specific plants, such as Atriplex hortensis, Carthamus tinctorius, Hylotelephium spp., and Saxifraga sibirica. Cross-culture analyses revealed a mosaic pattern of homogenous and heterogenous trends based on reported food species of plants/animals and their use reports. Our findings emphasize the significant role of women in sustaining local food diversity, food sustainability, and the preservation and security of the local food systems, cultural legacy, and household food management. Therefore, inclusive research addressing their social, economic, and environmental issues must be conducted. Furthermore, policies must incorporate women's traditional knowledge to build resilient food systems.

Effect of Some Heavy Metals Accumulation on the Proteins Content of Zea mays L. Plant

Effect of Some Heavy Metals Accumulation on the Proteins Content of Zea mays L. Plant

Impact of seed priming on the germination and initial seedling growth of two maize hybrids under alkaline stress

Maize (Zea mays L.) is a vital crop, but its productivity is hindered by soil alkalinity, characterised by high pH levels that reduce nutrient availability. This study explores the potential of calcium carbonate seed priming to enhance the germination and early growth of two maize hybrids, CO-6 and VGI (H) M-2, under alkaline conditions. The experiment involved priming seeds with a calcium carbonate solution and testing them in various alkalinity levels (0, 2, 4, 8, and 10%). Results showed that priming significantly improved shoot growth and root length in both hybrids CO-6 and VGI H (M)-2 exhibited varying levels of tolerance to alkalinity, with primed seeds generally outperforming unprimed seeds in shoot growth and root length. This study concludes that calcium carbonate priming can enhance maize tolerance to alkaline soils, improving overall plant health. Further field studies and biochemical tests are recommended to validate these findings and optimise maize cultivation in alkaline environments. This study offers a workable solution to the problems caused by soil alkalinity in maize cultivation, which advances sustainable agricultural techniques.

Contribution of biochar in maintaining the productivity of sandy soils after Acacia sp plantations under maize (Zea mays) cultivation at Ntsio in DRC.

Objective: The aim of this study was to evaluate the potential of biochar in maintaining the productivity of sandy soils at the Ntsio site after planting Acacia sp. Methodology and Results: The experimental design was a randomized complete block design with 3 treatments and three replications. Each experimental plot measured 50mX20m, separated each one by a distance of 5 m. The treatments were, respectively, T0: Conventional practice (control), T1: Plot with traditional carbonization ovens, T2: Plot with traditional carbonization ovens + one tonne of biochar ploughed in (equivalent to 10tonnes/ha). The experiment was carried out on an acidic soil with a pH of 4.8. Carbon and nitrogen contents were 3.45 % and 0.22 ppm respectively. The average CEC value was 2.08-meq/100 soil. Maize was used as a testing material. It appeared that during the first growing season the results were better than during the second one for all the parameters studied. However, in the second growing season, the biochar treatment (T1 and T2) produced maize plants with an average height statistically higher than the control. In the first growing season, the biochar-amended treatments produced higher yields, in contrast to the control soil. In the second season, yields were low except in the biochar amended treatment. The greatest decreases in yields were observed for T0 and T1 with a decrease at 67% and 68% respectively. However, On the other hand, in the plot where biochar was incorporated, the yield decrease was 20%. Conclusion and application of results: The results of this study show that the incorporation of biochar into sandy soils is essential for improving maize yields in the Acacia sp agroforestry system. The application of 10 t/ha-1 biochar in sandy soils has a positive effect on improving the following sandy soil properties: pH, carbon, phosphorus and CEC, compared to the control soil. The use of biochar in the Acacia sp based agroforestry system developed in DR Congo represent an opportunity to improve the productivity of sandy soils, to settle local farmers and persuade them to stop cutting forest trees for agricultural activities. Keywords: soil fertility, agroforestry, maize, biochar. RÉSUMÉ Objectif : Cette étude avait pour objectif d’évaluer le potentiel du biochar dans le maintien de la productivité des sols sableux du site de Ntsio après plantation d’Acacia sp. Méthodologie et résultats: Le dispositif expérimental choisi était celui en blocs complets randomisés avec 3 traitements et trois répétitions. Chaque parcelle expérimentale mesurait 50mX20m soit 1000 m2, séparée de 5 m de distance. Les traitements étaient respectivement, T0 : Pratique conventionnelle (témoin), T1 : Parcelle avec des fours à carbonisation traditionnelle, T2 : Parcelle avec des fours à carbonisation traditionnelle + enfouissement d’une tonne de biochar (équivalent à 10tonnes/ha). Il ressort des résultats sur les paramètres édaphiques que le sol sous étude était acide, avec un pH moyen de 4,8. Les teneurs en carbone et azote étaient respectivement de 3,45 et 0,22 ppm. Concernant la CEC, la valeur moyenne obtenue était de 2,08 méq/100 sols. Concernant la croissance et la production de maïs, il est démontré que pendant la première saison culturale les meilleurs rendements ont été obtenus pour tous les traitements. Cependant, au cours de la deuxième saison culturale, les traitements à base de biochar (T2 et T1) ont donné des plants de maïs avec une hauteur moyenne statistiquement supérieure au témoin. Pendant la première saison culturale, les traitements amendés au biochar ont donné les rendements élevés contrairement au sol témoin. Et à la seconde saison, les rendements ont été faibles sauf sur le traitement sous biochar. Les grandes baisses du rendement ont été observées pour le T0 et T1 respectivement de 67% et de 68%. Par contre, pour la parcelle où le biochar a été incorporé, la diminution n’a été que de 20%. Conclusion et application des résultats : Les résultats de la présente étude ont permis d’affirmer que l’incorporation du biochar s’avère très indispensable pour les sols sableux afin d’améliorer le rendement du maïs dans le système agroforestier à base d’Acacia sp. Le taux d'application de 10 t ha-1 de biochar dans les sols sableux a un affect positif sur l'amélioration des propriétés du sol sableux suivantes : le pH, le carbone, le phosphore et la CEC, par rapport au sol témoin. L’utilisation du biochar dans le système agroforestier à base d’Acacia sp développé en RD Congo constitue une opportunité pour améliorer la productivité des sols sableux, sédentariser les agriculteurs locaux et amener ces derniers à ne plus déboiser la forêt pour les activités agricoles. Mots-clés: fertilité des sols, agroforesterie, maïs, biochar.

A Moderate Water Deficit Induces Profound Changes in the Proteome of Developing Maize Ovaries.

Water deficit is a major cause of yield loss for maize (Zea mays), leading to ovary abortion when applied at flowering time. To help understand the mechanisms involved in this phenomenon, the proteome response to water deficit has been analysed in developing ovaries at the silk emergence stage and five days later. Differential analysis, abundance pattern clustering and co-expression networks were performed in order to draw a general picture of the proteome changes all along ovary development and under the effect of water deficit. The results show that even mild water deficit has a major impact on ovary proteome, but this impact is very different from a response to stress. A part of the changes can be related to a slowdown of ovary development, while another part cannot. In particular, ovaries submitted to water deficit show an increase in proteins involved in protein biosynthesis and in vesicle transport together with a decrease in proteins involved in amino acid metabolism and proteolysis. According to the functions of increased proteins, the changes may be linked to auxin, brassinosteroids and jasmonate signalling but not abscisic acid.

Assessment of Poultry Manure and Inorganic Fertilizers Influences on the Growth and Yield of Maize (Zea mays L.)

Assessment of Poultry Manure and Inorganic Fertilizers Influences on the Growth and Yield of Maize (Zea mays L.)

Conventional and Molecular Improvement of Maize for Drought Tolerance: Research Review

Maize (Zea mays L.) is an important staple crop for food, feed, and industry globally. Despite the importance of maize as a principal food crop in developing countries, drought is a major constraint that affects maize production, particularly in Sub-Saharan Africa, where maize is grown under rainfed conditions. Plant breeders have been striving to improve and develop drought-tolerant crops. Nevertheless, these efforts still cannot meet the demand for food security due to fast population growth and climatic change. Conventional maize breeding for drought tolerance follows a diverse approach that includes recurrent selection, backcrossing, pedigree breeding, and subsequently evaluating inbred lines and hybrids at optimum conditions, a managed screening site, and random stress across multiple environments. Molecular markers were used to select donor parents with drought-adaptive alleles and then integrated into elite maize lines to create a new population of drought-tolerant inbred lines.

Phylogenomic and synteny analysis of BAHD and SCP/SCPL gene families reveal their evolutionary histories in plant specialized metabolism.

Plant chemical diversity is largely owing to a number of enzymes which catalyse reactions involved in the assembly, and in the subsequent chemical modifications, of the core structures of major classes of plant specialized metabolites. One such reaction is acylation. With this in mind, to study the deep evolutionary history of BAHD and the serine-carboxypeptidase-like (SCPL) acyltransferase genes, we assembled phylogenomic synteny networks based on a large-scale inference analysis of orthologues across whole-genome sequences of 126 species spanning Stramenopiles and Archaeplastida, including Arabidopsis thaliana, tomato (Solanum lycopersicum) and maize (Zea mays). As such, this study combined the study of genomic location with changes in gene sequences. Our analyses revealed that serine-carboxypeptidase (SCP)/serine-carboxypeptidase-like (SCPL) genes had a deeper evolutionary origin than BAHD genes, which expanded massively on the transition to land and with the development of the vascular system. The two gene families additionally display quite distinct patterns of copy number variation across phylogenies as well as differences in cross-phylogenetic syntenic network components. In unlocking the above observations, our analyses demonstrate the possibilities afforded by modern phylogenomic (syntenic) networks, but also highlight their current limitations, as demonstrated by the inability of phylogenetic methods to separate authentic SCPL acyltransferases from standard SCP peptide hydrolases.This article is part of the theme issue 'The evolution of plant metabolism'.

Effect of Sowing Methods, Weed Management and Growth Promoters on Yield and Quality Behavior of Kharif Maize (Zea mays L)

The present investigation was carried out during two consecutive kharif season in years 2022 and 2023 at students. Instructional Farm, Department of Agronomy, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur (U. P). The experiment was laid out in Split Plot Design keeping sowing methods in main plot and weed management practices in sub plots with growth promoters in sub – sub plots with three replications. There was two sowing methods viz; Conventional methods (S1) and Ridge methods (S2). Whereas weed management practices were five, viz; Weed Free (W1), Weedy Check (W2), Atrazine Pre-emergence @ 1.25 Kg /ha (W3), Halosulfuron methyl Post-emergence @ 65g a.i./ha (W4), Atrazine Pre-emergence @ 0.75 l/ha + Halosulfuron methyl Post-emergence @ 35g ai./ha (W5). and there was Growth promoters’ practices were three viz; Gibberellic acid (Sayish) (G1), Amino acid + Humic acid (Spring ever) (G2), Cytokinins + Enzymes (Ambition) (G3). The experiment was shown on 10th July during 2022 and 13rd July during 2023 using hybrid maize DKC-9144. The crop was harvested at full ripe stage on 11 October and 14 October, in 2022 and 2023, respectively. The highest grain yield, biological yield, stower yield, harvesting index, protein content and protein yield was found under the treatment of S2 (Ridge method) in sowing method, treatment W2 (weed free) in weed control methods and treatment G3 (Cytokinins + Enzymes) in plant growth promotor.

Combining ability for grain yield and low-N tolerance of intermediate/late maturing maize (Zea mays) inbred lines

ABSTRACT Low soil nitrogen (N) is a significant challenge to maize (Zea mays L.) production in Sub-Saharan Africa, particularly for small-scale farmers. Developing maize hybrids tolerant to low N is crucial for improving yields under such conditions. This study examined the genetic basis of agronomic traits in intermediate/late maturing maize inbred lines under contrasting N conditions, focusing on general combining ability (GCA) and specific combining ability (SCA) effects. Two hundred and thirty-seven F1 hybrids from 79 inbred lines crossed with three testers in a line x tester mating design, were evaluated across eight environments in Nigeria. Line x tester analysis revealed that GCA effects, primarily from lines, predominantly influenced grain yield and other traits across both N conditions, except for ear height and plant aspect under low N, where SCA effects also had significant impact. A significant (p ≤ 0.01) positive correlation was observed between GCA and SCA effects, suggesting a positive relationship between additive and non-additive genetic components. Lines SMLW146 and SMLW147 were identified as valuable resources for breeding low-N tolerant hybrids. Additionally, considering non-additive effects, hybrids SMLW22 × SAM50M and SMLW106 × SAM50M (under low-N) and SMLW3 × IITA1876, SMLW84 × IITA1876, and SMLW165 × IITA1876 (under optimum-N) were promising combinations for high grain yield. Morphological traits like plant height and ear height, phenological traits like days to anthesis and silking, and qualitative traits like ear aspect and plant aspect were identified as important for selecting genotypes with improved grain yield under low-N conditions.

Effects of different nutrient supply options on system productivity, nitrogen use efficiency and soil enzyme activities in maize - wheat cropping system cropping system

The field experiments were conducted during during kharif and the following rabi seasons of 2011-12 and 2012-13 with five different treatments in maize (Zea mays L.) and wheat (Triticum aestivum (L.) emend Fiori &amp; Paol.) cropping systems. Application of 50% RDF + 50% RDN recorded maximum WEY of maize (3.23 and 4.58 t/ha) and system productivity (8.20 and 9.03) over rest of the treatments, but remained statistically similar with other treatments except control during 2011-12 and 2012-13, respectively. The highest ANUE (5.07 and 15.36 kg grain yield increase/kg N applied) of maize crop was recorded at 50% RDF + 25% RDN + BF, followed by 50% RDF + 25% RDN during both the years. The highest ANUE (17.64 and 17.18 kg grain yield increase/kg N applied) of wheat crop were recorded from 37.5% RDF + 37.5% RDN + BF during both the years, respectively. Application of 50% RDF + 50% RDN to maize resulted in increased the value of MBC (18.0 and 18.4%), DH (22.9 and 18.6%), alkaline phosphatase (33.3 and 29.6%) and urease (37.1 and 37.8%) over control during 2011 and 2012, respectively. An increased value of MBC (38 and 34.6%), DH (29.2 and 29.8%), alkaline phosphatase (37.2 and 34.9%) and urease (30.1 and 25.6%) was recorded with the application of 37.5% RDF + 37.5% RDN + BF to wheat over control during both the years, respectively. Bangladesh J. Bot. 53(3): 429-438, 2024 (September)