Affecting Maize Production Research Articles

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.

Integration of Conventional Breeding and Molecular Tools for Drought Tolerance in Maize: Review

Maize is an important staple crop for food, feed and industry globally. Despite the importance of maize as a principal food crop in developing country, drought is a major constraint that affects maize production, particularly in Sub-Saharan Africa where maize is grown under rainfed condition. Plant breeder has been striving to improve and develop drought tolerance crops. Nevertheless, these efforts still cannot meet the demand of food security due to fast population growth and climatic change. Secondary traits with associated to grain yield, advanced phenotyping, marker assisted selection/QTL, genomic wide association study and genomic selection methods are more expected to help for improvement of drought tolerance in maize. This article discussed the most secondary traits used for selection, plant physiological traits and crossing among drought tolerance elite lines and evaluation their segregants as well as hybrids performance under stress and optimum conditions. Emphasis also given to molecular dissection of drought tolerance complex trats using GWAS and /or gene discovery at hotspot regions for secondary traits, marker-assisted backcrossing and genome selection have been highlighted for increasing genetic gain in grain yield and predicating the breeding value for selection. Thus, further improvement is essential integration of conventional breeding and genomic tools for development of resilience maize varieties for drought tolerance in maize.

Toxic Effects of Bt-(Cry1Ab+Vip3Aa) Maize (“DBN3601T’’ Event) on the Asian Corn Borer Ostrinia furnacalis (Guenée) in Southwestern China

Asian corn borer (ACB), Ostrinia furnacalis, is an important agricultural pest affecting maize production in southwestern China, but knowledge of the toxic effect of Bt maize on the pest has been insufficient until now. In this study, we determined the susceptibility of ACB to Cry1Ab, Vip3Aa, and their complex proteins and evaluated the efficacy of Chinese domestic Bt-(Cry1Ab+Vip3Aa) maize (“DBN3601T” event) against the pest in Yunnan Province of southwestern China. The susceptible bioassay indicated that the LC50 values of the Cry1Ab and Cry1Ab+Vip3Aa proteins expressed by the Bt maize varieties against ACB larvae were 51.42 and 46.85 ng/g, respectively; however, the ACB larva was insensitive to the Vip3Aa protein. The Cry1Ab+Vip3Aa protein contents in V6–V8 leaves, VT tassels, R1 silks, R2 kernels, R3 stalks and R3 cobs of the Bt-(Cry1Ab+Vip3Aa) maize were 114.20, 30.69, 3.77, 8.92, 11.09 and 10.99 μg/g, respectively. The larval feeding test indicated that the Bt-(Cry1Ab+Vip3Aa) maize was more toxic to the early instar larvae, and the survival time of larvae fed on the leaves was the shortest, while it survived the longest on stalks. The identification of maize resistance levels in the field showed that both larval density and plant damage score of Bt-(Cry1Ab+Vip3Aa) maize were significantly lower than those in conventional maize. It is concluded that the Bt-(Cry1Ab+Vip3Aa) maize can be used for control of the ACB in southwestern China.

Effects of drip irrigation coupled with controlled release potassium fertilizer on maize growth and soil properties

Drip irrigation and the application of controlled-release fertilizers are two effective and important technical measures to conserve water and fertilizer resources and promote the growth and development of maize. However, the underlying physiological mechanism of how drip irrigation combined with controlled release potassium chloride affects maize production and soil properties remains unknown. In different soil water conditions, pot experiments were conducted during the summer maize growing season in 2022 and 2023 to measure maize grain yield, irrigation water productivity, apparent recovery efficiency of potassium, plant physiological characteristics, and soil enzyme activities under the coupling of two irrigation methods (flood irrigation and drip irrigation) and three potassium fertilizer types (potassium chloride (KCl), controlled release potassium chloride (CRK), and 70 % CRK mixed with 30 % KCl). The results revealed that drip irrigation had 6.5–8.1 % and 6.7–9.4 % higher average soil volumetric water content and 3.8–8.1 % and 4.5–13.0 % higher irrigation water productivity than flood irrigation in the two maize growth seasons, respectively. Under the drought conditions, the treatments of 70 % CRK-30 % KCl application led to a significant increase in maize yield by 9.5–10.7 % and 12.2–16.8 % and apparent recovery efficiency of potassium by 8.3–14.2 % and 10.7–10.8 % compared to CRK application treatments in 2022 and 2023, respectively. Compared with the other treatments, the treatment of drip irrigation coupled with 70 % CRK-30 % KCl application under drought conditions (DIDMK) resulted in 4.5–28.7 % and 1.1–31.9 % higher grain yield, 8.2–64.4 % and 8.6–66.8 % higher irrigation water productivity, and 5.9–28.0 % and 6.7–18.9 % higher apparent recovery efficiency of potassium in 2022 and 2023, respectively. Meanwhile, the leaf net photosynthetic rate, rubisco, catalase, peroxidase, and soil enzyme activities of DIDMK treatment were also maintained at a high level. Our results indicated that drip irrigation coupled with 70 % CRK-30 % KCl application were the optimal water and potassium supply modes for maize production. This study can provide useful information regarding summer maize sustainable production and provide theoretical and technical support for summer maize irrigation and potassium fertilizer application technologies in water-scarce regions of China and other similar regions around the world.

ZmNF-YA1 Contributes to Maize Thermotolerance by Regulating Heat Shock Response.

Zea mays (maize) is a staple food, feed, and industrial crop. Heat stress is one of the major stresses affecting maize production and is usually accompanied by other stresses, such as drought. Our previous study identified a heterotrimer complex, ZmNF-YA1-YB16-YC17, in maize. ZmNF-YA1 and ZmNF-YB16 were positive regulators of the drought stress response and were involved in maize root development. In this study, we investigated whether ZmNF-YA1 confers heat stress tolerance in maize. The nf-ya1 mutant and overexpression lines were used to test the role of ZmNF-YA1 in maize thermotolerance. The nf-ya1 mutant was more temperature-sensitive than the wild-type (WT), while the ZmNF-YA1 overexpression lines showed a thermotolerant phenotype. Higher malondialdehyde (MDA) content and reactive oxygen species (ROS) accumulation were observed in the mutant, followed by WT and overexpression lines after heat stress treatment, while an opposite trend was observed for chlorophyll content. RNA-seq was used to analyze transcriptome changes in nf-ya1 and its wild-type control W22 in response to heat stress. Based on their expression profiles, the heat stress response-related differentially expressed genes (DEGs) in nf-ya1 compared to WT were grouped into seven clusters via k-means clustering. Gene Ontology (GO) enrichment analysis of the DEGs in different clades was performed to elucidate the roles of ZmNF-YA1-mediated transcriptional regulation and their contribution to maize thermotolerance. The loss function of ZmNF-YA1 led to the failure induction of DEGs in GO terms of protein refolding, protein stabilization, and GO terms for various stress responses. Thus, the contribution of ZmNF-YA1 to protein stabilization, refolding, and regulation of abscisic acid (ABA), ROS, and heat/temperature signaling may be the major reason why ZmNF-YA1 overexpression enhanced heat tolerance, and the mutant showed a heat-sensitive phenotype.

Comprehensive diallel analysis of combining ability and heterosis to Fusarium verticillioides ear rot resistance in maize

AbstractMaize (Zea mays L.) Fusarium ear rot (FER), which is caused by the fungal pathogen Fusarium verticillioides, is a major ear disease affecting maize production in China. Developing resistant maize hybrids is a cost‐effective and environmentally friendly method of reducing yield losses due to FER. Using the nail punch inoculation method, 17 highly resistant and 16 highly susceptible inbred lines were identified in this study, and a large‐scale maize hybrid consisting of 528 F1’s was produced using a half‐diallel cross model. The hybrids were inoculated with F. verticillioides in 6 year–location environment combinations during 2020–2022. Our results showed that estimates of genotypic, environmental, and genotype × environment interaction variance components were very significant (p < 0.001). All the crosses generated from highly resistant inbred lines exhibited high kernel resistance, whereas those generated from highly susceptible inbred lines mostly exhibited high susceptibility to FER. Crosses between resistant and susceptible inbred lines showed intermediate resistance to FER. The general combining ability (GCA) effect was greater than the specific combining ability effect across multiple environments, indicating that the inheritance of FER resistance was mainly influenced by additive genetic effects. The correlation coefficient between the expected GCA value and hybrid resistance was 0.789, whereas that between the mid‐parent value and hybrid resistance was only 0.644. Inbred performance per se and their corresponding hybrids across multiple environments were significantly correlated (r = 0.823). However, no relationship was observed between the FER resistance of F1’s and that of their parental heterotic groups.

Factors Affecting Maize Production in Kiteto District, Manyara Region, Tanzania: Cross Sectional Design

Factors Affecting Maize Production in Kiteto District, Manyara Region, Tanzania: Cross Sectional Design

First report of the maize cyst nematode Heterodera zeae in Sichuan Province of Southwest China.

Maize is the largest crop planted in China. Nine species of cyst nematodes have been reported to affect maize production. Heterodera zeae, H. avenae and Punctodera chalcoensis can cause significant maize yield losses annually (Luc et al. 2005). In 1971, the maize cyst nematode H. zeae was first detected in Rajasthan, India (Koshy et al. 1971). Subsequently, it has been reported in many other countries such as the United States, Greece, Pakistan, and Egypt. In China, H. zeae was first identified in the maize fields of Laibin City, Guangxi Zhuang Autonomous Region (Wu et al., 2017). Cui et al. (2020) identified H. zeae in a maize field of Yuzhou City, Henan Province of Central China in 2018. From 2018 to 2022, a survey of cyst-forming nematodes was conducted in Southwest China. Fifteen soil samples of about 500 g each were collected from Luding County, Ganzi Prefecture of Sichuan Province. No major aboveground symptoms were shown on maize, but a few females were observed on the roots of maize in one field. The cysts and second-stage juveniles (J2s) were collected from each soil sample using Cobb's screening gravity method. A total of 8.50±2.0 cysts per 100 ml of soil on the average were observed in the field. A thin subcrystalline layer was discernible only in young cysts. Morphological and molecular studies of cysts and J2s indicated that the nematodes were identified to be H. zeae in a maize-field. Morphologically, the cysts were in a lemon shape, light brown or pearly white in color. The vulval cone was prominent. Fenestra ambifenestrate, and semifenestra were separated by a fairly wide vulval bridge, fenestral length and width were variable, and the cyst wall was shown in a zigzag pattern. The J2s' body was in a vermiform, tapering at both ends, with a hyaline tail. Stylet was strongly developed with round or slightly anteriorly directed knobs. Morphological measurements of the cysts (n = 9) determined that the mean body length was 417.2 μm (403.6 to 439.4 μm), body width was 429.7 μm (397.6 to 456.9μm); length-width ratio was 1.4 (0.75 to 3); fenestra length was 525.3 μm (498.5 to 570.7 μm); and the mean semifenestra width was 458.6 μm (403.6 to 546.3 μm). Morphometric measurements of second-stage juveniles (n = 20) showed a body length of 419.7μm (355.8 to 492.5 μm); a stylet length of 20.8 μm (19.51 to 23.3μm); a tail length of 41.5 μm (20 to 49.4 μm); and a hyaline tail length of 20.7 μm (16.6 to 24 μm). The main morphological characteristics and measured values were basically consistent with those described by Cui et al. (2022), and all of which were similar to those of H. zeae. Amplification of DNA from random single cysts (n = 5) was conducted using the protocol described by Cui et al. (2022). The rDNA-internal transcribed spacer (ITS) was amplified and sequenced using a pair of universal primers TW81 (5'-GTTTCCGTAGGTGAA CCTGC-3') and AB28 (5'-ATATGCTTAAGTTCAGCGGGT-3'). The ITS sequences were deposited at GenBank with the accession number OR811029.1. Alignments of sequences showed an identity of 98% with H. zeae sequences from China (OP692769.2, MW785772.1) and the USA (GU145616.1), which were confirmed using a pair of species-specific primers HzF1 (5'-GGGGAGGTGAATGTGGG-3') and HzR1 (5'-CCTTTGGCAATCGGTGA-3') of H. zeae with a targeted PCR fragment of 393 bp (Cui et al. 2022). Pathogenicity was conducted and confirmed by infection and reproduction on maize. Seeds (cv. Zhengda 619) were sown in three pots that contained 150 ml of a sterile soil mixture (loamy soil: sand=1:1), and 5 cysts (103 eggs/cyst on the average) were inoculated in each pot at 25/30°C, under a 12-h dark/12-h light condition (Cui et al. 2023). Fifteen days after sowing, third- and fourth-stage juveniles were observed in the rootstained with acid fuchsin, and a total of 32 cysts per maize plant on the average were collected at 40 days after sowing. The new cysts' morphological and molecular characteristics were identical to the cysts from the original soil samples. To the best of our knowledge, this is the first report of H. zeae as a pathogen on maize in Sichuan Province, Southwest China. Our findings will be useful for management and further research of maize cyst nematodes.

Impact of Microdosing Practices on Technical Efficiency: An Analysis Accounting for Selection Bias Among Smallholder Maize Farmers in Burkina Faso

Smallholder maize farmers are currently confronted with the arduous challenge of managing limited financial resources while incessantly facing the issue of land degradation. To address this issue, an alternative solution has been implemented to optimize the use of chemical fertilizer by adopting microdosing. This innovative system not only helps them enhance their agricultural productivity but also allows them to protect the environment. However, it is unclear how microdosing adoption could increase the technical efficiency (TE) of maize production. Therefore, this research aims to assess how the adoption of microdosing affects the technical efficiency of maize production as well as identify the key factors that influence the technical efficiency of maize production in Burkina Faso. To achieve this goal, farm household survey data was conducted with 210 randomly selected farmers from the Plateau Central and northern regions of Burkina Faso. To account for potential selection biases that could result from both observable and unobservable factors, we used a sample selection stochastic production frontier model and a propensity score matching approach. A stochastic meta-frontier approach was applied to estimate TE differences and the technology gap between adopters and non-adopters. The findings showed that adopters of microdosing have an average efficiency of 68 percent, which is higher than the 53 percent estimated for non-adopters. Adopters of microdosing have been found to have high TE and better agricultural technology than non-adopters. The meta-frontier estimation revealed that the adoption of improved maize varieties would yield better returns. This study contributes significantly to the literature on how fertilizer microdosing affects maize productivity, as well as the policy implications of targeting and encouraging smallholder maize farmers in Burkina Faso to optimize the use of productive inputs and improve maize output by using microdosing.

Early-season maize responses to salt stress: Morpho-physiological, leaf reflectance, and mineral composition

Salt stress is a major environmental factor that affects maize production. The impact of salt stress during the early vegetative stage inhibits growth and development. In this study, two maize hybrids, A6659 and P1316, were subjected to five salinity treatments with electrical conductivity 0, 3, 6, 9, and 12 dS m−1 for 28 days. A total of 26 traits were evaluated, including morpho-physiological, biomass, leaf reflectance, and mineral composition in two independent studies. Under salt stress, stomatal conductance and transpiration were reduced, resulting in a canopy temperature rise of 4 °C. A higher salinity level (12 dS m−1) reduced plant height (47%) and total leaf area (44%), consequently reducing total shoot dry weight (37%) and total root dry weight (24%). Leaf minerals such as potassium, magnesium, and phosphorous declined with increasing salt concentrations. The elevated salt concentration in the rhizosphere caused an increase in leaf reflectance at the near-infrared (NIR) region, which is attributed to macronutrient deficiency under stress conditions. The results demonstrated that maize could withstand salt stress up to 3 dS m−1, beyond which plant performance declines depending on the genetics. This study provides insights into key traits that can be used for screening or breeding maize for early-season salt stress tolerance.

Financial losses due to fumonisin contamination in the Texas High Plains maize

Fumonisins are one of the main problems affecting maize production in the Texas High Plains (THP), where its agroclimatic conditions make it a perennial hotspot for mycotoxin contamination. In 2017, a fumonisin outbreak in the THP maize motivated stakeholders’ request to repeal a subsection of the Texas Administrative Code, §61.61(a)(7) (Fumonisin Rule), and its related Texas Feed Industry Memorandum (Memo 5–20), which previously permitted the blending of maize containing high fumonisin levels with maize containing ≥ 5 mg/kg under state authority, and pivot to FDA fumonisin guidance. Shortly after, the USDA Risk Management Agency (RMA's) reintroduced Discount Factors (DFs) in annual Special Provisions (SP) that outline price reductions related to fumonisin contamination in maize. In this research, we estimate the potential economic burden posed by these changes through a two-part approach. In part one, we construct a decision model that explores the final disposition of fumonisin-contaminated maize based on blending permissions, fumonisin levels, and crop insurance status. In part two, we estimate the economic impact by inserting output values of the decision model into financial equations that consider testing costs, transportation fees, and discounts from crop insurance and grain elevators when applicable. Our economic analysis projects that the financial losses during a THP crop year with high fumonisin levels could range from $15.1 to $135.5 million without the option to blend under conditions of the revised RMA discount schedule. Findings further highlight crop insurance as the most promising risk management strategy for farmers in areas susceptible to fumonisin contamination.

Calcium lignosulfonate-induced modification of soil chemical properties improves physiological traits and grain quality of maize (Zea mays) under salinity stress.

Salinity negatively affects maize productivity. However, calcium lignosulfonate (CLS) could improve soil properties and maize productivity. In this study, we evaluated the effects of CLS application on soil chemical properties, plant physiology and grain quality of maize under salinity stress. Thus, this experiment was conducted using three CLS application rates, CLS0, CLS5, and CLS10, corresponding to 0%, 5%, and 10% of soil mass, for three irrigation water salinity (WS) levels WS0.5, WS2.5, and WS5.5 corresponding to 0.5 and 2.5 and 5.5 dS/m, respectively. Results show that the WS0.5 × CLS10 combination increased potassium (K 0.167 g/kg), and calcium (Ca, 0.39 g/kg) values while reducing the sodium (Na, 0.23 g/kg) content in soil. However, the treatment WS5.5 × CLS0 decreased K (0.120 g/kg), and Ca (0.15 g/kg) values while increasing Na (0.75 g/kg) content in soil. The root activity was larger in WS0.5 × CLS10 than in WS5.5 × CLS0, as the former combination enlarged K and Ca contents in the root while the latter decreased their values. The leaf glutamine synthetase (953.9 µmol/(g.h)) and nitrate reductase (40.39 µg/(g.h)) were higher in WS0.5 × CLS10 than in WS5.5 × CLS0 at 573.4 µmol/(g.h) and 20.76 µg/(g.h), leading to the improvement in cell progression cycle, as revealed by lower malonaldehyde level (6.57 µmol/g). The K and Ca contents in the leaf (881, 278 mg/plant), stem (1314, 731 mg/plant), and grains (1330, 1117 mg/plant) were greater in WS0.5 × CLS10 than in WS5.5 × CLS0 at (146, 21 mg/plant), (201, 159 mg/plant) and (206, 157 mg/plant), respectively. Therefore, the maize was more resistance to salt stress under the CLS10 level, as a 7.34% decline in yield was noticed when salinity surpassed the threshold value (5.96 dS/m). The protein (13.6 %) and starch (89.2 %) contents were greater in WS0.5 × CLS10 than in WS5.5 × CLS0 (6.1 %) and (67.0 %), respectively. This study reveals that CLS addition can alleviate the adverse impacts of salinity on soil quality and maize productivity. Thus, CLS application could be used as an effective soil amendment when irrigating with saline water for sustainable maize production.

A combination of joint linkage and genome-wide association study reveals putative candidate genes associated with resistance to northern corn leaf blight in tropical maize.

Northern corn leaf blight (NCLB), caused by Setosphaeria turcica, is a major fungal disease affecting maize production in sub-Saharan Africa. Utilizing host plant resistance to mitigate yield losses associated with NCLB can serve as a cost-effective strategy. In this study, we conducted a high-resolution genome-wide association study (GWAS) in an association mapping panel and linkage mapping with three doubled haploid (DH) and three F3 populations of tropical maize. These populations were phenotyped for NCLB resistance across six hotspot environments in Kenya. Across environments and genotypes, NCLB scores ranged from 2.12 to 5.17 (on a scale of 1-9). NCLB disease severity scores exhibited significant genotypic variance and moderate-to-high heritability. From the six biparental populations, 23 quantitative trait loci (QTLs) were identified, each explaining between 2.7% and 15.8% of the observed phenotypic variance. Collectively, the detected QTLs explained 34.28%, 51.37%, 41.12%, 12.46%, 12.11%, and 14.66% of the total phenotypic variance in DH populations 1, 2, and 3 and F3 populations 4, 5, and 6, respectively. GWAS, using 337,110 high-quality single nucleotide polymorphisms (SNPs), identified 15 marker-trait associations and several putative candidate genes linked to NCLB resistance in maize. Joint linkage association mapping (JLAM) identified 37 QTLs for NCLB resistance. Using linkage mapping, JLAM, and GWAS, several QTLs were identified within the genomic region spanning 4 to 15 Mbp on chromosome 2. This genomic region represents a promising target for enhancing NCLB resistance via marker-assisted breeding. Genome-wide predictions revealed moderate correlations with mean values of 0.45, 0.44, 0.55, and 0.42 for within GWAS panel, DH pop1, DH pop2, and DH pop3, respectively. Prediction by incorporating marker-by-environment interactions did not show much improvement. Overall, our findings indicate that NCLB resistance is quantitative in nature and is controlled by few major-effect and many minor-effect QTLs. We conclude that genomic regions consistently detected across mapping approaches and populations should be prioritized for improving NCLB resistance, while genome-wide prediction results can help incorporate both major- and minor-effect genes. This study contributes to a deeper understanding of the genetic and molecular mechanisms driving maize resistance to NCLB.

Economic Analysis of Factors Affecting Maize Production in Tanzania: Time Series Analysis


 
 
 Maize is an important food and income earner for rural and urban dwellers in Tanzania. Despite efforts done by the government and private sector, the yield of maize has remained significantly below the average of less than 2 metric tonnes per hectare. This threatens food insecurity and poverty for rural people. This study analyses the economic factors affecting maize production in Tanzania for a period of 61 years. Time series data on aggregate maize production, fertilizer price, total area under maize cultivation, the total seed used, expected price of maize and average annual rainfall for the period 1961-2020 were analyzed using a vector error correction model. Empirical findings revealed that the total area under maize cultivation, the total seed used and average annual rainfall have a positive relationship with aggregate maize production; but fertilizer price and expected price of maize have a negative relationship with aggregate maize production. In terms of statistical significance, the study found that the area cultivated was statistically significant; but seed used, price of fertilizer, expected price of maize and average annual rainfall were statistically insignificant. The study recommends formulation of policies about intensive agriculture, fertilizer and seed subsidization and irrigation schemes to increase productivity.
 
 
 

Faktor-Faktor Yang Mempengaruhi Produksi Jagung Di Kecamatan Poigar Kabupaten Bolaang Mongondow

This study aims to determine what factors affect maize production in Poigar District. This research was conducted in Poigar District where most of the people are farmers. This research activity was carried out from May to June in 2022. The results showed that the results of hypothesis testing in the F (simultaneous) test showed that together the variable land area, seed variable, urea fertilizer variable, phonska fertilizer variable, labor variable work, pesticide variables, and farming experience variables affect the amount of corn production in Poigar District. And testing the hypothesis on the T test that partially the factors that affect corn production at = 0.05 are factors that significantly affect corn production in Poigar District, namely factor (X1) land area, factor (X4) Phonska fertilizer, factor (X5) significant workforce in Poigar District.

PRODUCTION ECONOMICS OF MAIZE (ZEA MAYS) IN SURKHET, NEPAL

A study was undertaken on the economics of producing maize in the major maize-growing areas of Lekbeshi and Gurbhakot Municipality in Surkhet, Nepal. The study’s overarching goal was to assess and analyze the economics of producing maize in Surkhet A few specific goals were to identify the socio-demographic features of maize growers, as well as maize production and productivity. Many variables affect maize yield, including weed control, irrigation, insect and pest damage, and fertilizer use. Production economics examines the link between inputs and outputs, including labor, all economic investments, seeds, fertilizer, and irrigation, as well as outputs such as the price of produced maize. The required information was obtained with the help of a pre-tested questionnaire and 2 focus group discussions. Regarding the gender of the household head, most of them were male 75% and female 25% denoting a male-dominated society. Most of the respondents were female 52%. The fact that maize is primarily grown for self-consumption in this area makes it difficult to calculate costs, investments, returns, and benefits. Key problems that affect maize production include pests, diseases, marketing, fertilizer costs, low-quality seed, seed scarcity, and the lack of efficient technology. Fertilizers, seeds, and prepared fields were discovered to increase maize output. To improve maize production, key factors should be considered and limits reduced.

Effect of Intercropping Maize and Beans on the Maize Yields in Isingiro Town Council, Isingiro District, South Western Uganda

The study aimed at determination of the effect of intercropping maize and beans on the maize yields Isingiro Town Council, Isingiro District, South Western Uganda. The study used a randomized complete block (RCBD) experiment in which 8 treatments in 4 replicas of each to make a total of 32 sub-plots. Two rows of maize spaced at 4.5cm within rows and 90cm between rows were intercropped with two rows of velvet beans spaced at 30cm with rows and 90cm between rows. Two rows of NABE16 spaced at 4.5cm within rows and 75cm between rows were intercropped with maize a pacing of 5.5cm within rows and 75cm between rows. Rows of beans were separated from those of maize by 75cm in a 10m by 8m sub-plot. The experiment was conducted in two seasons (March to May 2020 and August to November 2021). Standard agronomical practices were followed from planting to harvesting, after which dry maize grain weight was taken and recorded. Data analysis was done using ONE WAY ANOVA in STATA version 13. Results show that the significant statistical difference in season one (p = 0.0000)** was higher than that in season two (p = 0.0211)*. The study concluded that unpredictable (too much or too little) rainfall negatively affects maize productivity. Early planting and application of organic fertilizers were recommended to improve maize productivity.

Variability in Yield Response Strongly Affects Maize Productivity and Nutrient Requirements

Smallholder maize productions systems in western Kenya exhibited wide spatial and temporal variability in yield responses to N, P and K application at the field level. Nutrient omission trials provide evidence of strong and ubiquitous N limitations and high vulnerability for rapid decline in P and K under continuous cropping without balanced nutrient applications.

Epicoccum spp. Causing Maize Leaf Spot in Heilongjiang Province, China.

Maize leaf spot occurs worldwide and affects maize production. Maize can be infected by several pathogens causing leaf spot, such as Bipolaris zeicola, Bipolaris maydis, Curvularia species, Alternaria species, etc. In the current study, 30 Epicoccum isolates recovered from symptomatic maize leaves were identified based on morphological characteristics, pathogenicity, and multilocus sequence analyses of nuLSU, ITS, tub2, and rpb2. These maize isolates were grouped into five Epicoccum species, including E. nigrum, E. layuense, E. sorghinum, E. latusicollum, and E. pneumoniae. Pathogenicity tests showed that all five Epicoccum species could produce small ellipse- and spindle-shaped spots on maize leaves. The lesion center was grayish yellow to dark gray and surrounded by a chlorotic area. Furthermore, the Epicoccum isolates exhibited high pathogenicity to 20 main maize varieties of Heilongjiang Province but showed different sensitivities to the commonly used fungicides carbendazim and tebuconazole. In addition, these Epicoccum isolates showed different production capacity of pectinase, cellulase, protease, amylase, laccase, and gelatinase, but all showed high lipase activity. This is the first report globally of E. layuense, E. latusicollum, and E. pneumoniae as causal agents of maize leaf spot. E. pneumoniae was first reported as a plant pathogen.

Maize yield as affected by the interaction of fertilizer nitrogen and phosphorus in the Guinea savanna of Nigeria

The soils of the Nigeria savannas are particularly low in nitrogen (N) and phosphorus (P) and negatively affects maize productivity. The main objective of the study was to evaluate the interactive effect of N and P fertilizers on maize growth, grain yield, nitrogen uptake and N use efficiency. Field experiments were conducted during the 2015 and 2016 cropping seasons at Iburu in southern Guinea and Zaria in northern Guinea savanna zones of Nigeria. The treatments consisted of three levels of nitrogen (0, 60, and 120 kg N ha−1) and three levels of phosphorus (0, 13, and 26 kg P ha−1). The experimental design consisted of three replications in a split-plot design, with N as the main plot and P as the subplot. Our results show that the response of maize to N depends on the application of P. Higher yields were obtained with the combined application of 120 kg N ha−1 and 26 kg P ha−1 in both locations. With no P applied, plant N uptake (PNU) was greater at N rate of 120 kg ha−1 at Iburu while in Zaria, it increases with increase in N from 0 to 60 kg ha−1. When P was applied at 13 kg ha−1, the PNU increased by 52 and 66% at Iburu while in Zaria the increases were 51 and 57% each with N application of 60 and 120 kg ha−1, respectively, compared with zero N rate. The values for N recovery efficiency (NRE) and agronomic efficiency (AE) were lower for N rate of 120 than for 60 kg ha−1 irrespective of P application rate at both locations. The N utilization efficiency (NUTE) however was higher at 120 N kg ha−1 under 26 kg P ha−1across locations. It can be concluded from these results that in low fertile soils environments such as the Nigeria savannas, N fertilizer should be applied along with P fertilizer for optimum growth, grain yield and nitrogen use efficiency of maize.