Growth Of Maize Plants Research Articles

Molecular Identification of Trichoderma Isolates and Their Effect in Combination with Zyngiberaceae Extracts on Maize Downy Mildew Incidence and Plant Growth

Research was done to molecularly identify Trichoderma isolates and to study the effect combination of Trichoderma isolates and Zingiberaceae extracts on downy mildew intensity as well as the growth of maize. The experiment was arranged in completely randomized design with three replicates. The experiment consisted of combination between Trichoderma isolates (no Trichoderma, East Lampung isolate, and Plant Clinic isolate) and Zingiberaceae extracts: ginger/jahe (Zingiber officinale), turmeric/kunyit (Curcuma longa), lengkuas (Alpinia galanga), galangale/kencur (Kaempferia galanga), temulawak (Curcuma zanthorrhiza), and temu hitam (Curcuma aeroginosa). Variables observed were disease incidence, incubation periode, plant height, and dry matter weight. Data were analyzed using analyses of variance and the difference between means were tested using LSD test at 5% significant level. Based on molecular identification, both Trichoderma isolates (East Lampung isolates and Plant Clinic isolate) are Trichoderma asperrelum. The results showed that combination of T. asperellum isolates and Zingiberaceae extracts lowered the disease incidence of maize downy mildew, prolonged the incubation period, increased plant height and dry matter weight. The best result was shown by combination of T. asperellum isolate from NTF East Lampung and tumeric extract.

Growth, chlorophyll content and yield of maize and banana plants in an agroforestry system in Kisii County, Kenya

Diverse tree species when employed in agroforestry systems may serve as an alternative to increasing soil fertility through nitrogen fixation. However, it is not clearly known how intercropping maize and banana with Sesbania sesban, Calliandra callothyrsus and Leucaena diversifolia may affect growth of maize and banana. The purpose of this study was to evaluate the effect of intercropping agroforestry trees species with maize and banana on the growth, chlorophyll content and yield of maize and banana. Field experiment was laid out at Kenya Agricultural Livestock and Research Organization farm (KALRO) located in Kisii County. The Williams varieties of banana of the same age were obtained from KALRO -Thika and Hybrid seed maize, H513 obtained from Kenya seed company, Kisumu. The agroforestry tree seedlings were spaced: 0.5m by 1m, 0.9m by 0.9m by 0.6m deep and 0.3m by 0.75m between banana and maize respectively. Three replicates were used with seven treatments of Pure maize, pure banana, maize-banana-Calliandra, maize-banana-Leucaena, maize-banana-sesbania, maize-banana and maize-fertilizer, all in a randomized complete block design. Data on maize growth and chlorophyll content was collected at intervals of 2 weeks which commenced 30 days after planting while yield was determined at the end of growing seasons. Data was subjected to the Analysis of Variance. Maize plants and banana that were intercropped with Sesbania sesban had significantly (P≤0.05) highest growth, chlorophyll content and yield compared to other treatments. Therefore, Sesbania sesban is recommended as a suitable agroforestry tree species for intercropping with maize and bananas.

Enhanced Physiological and Biochemical Performance of Mung Bean and Maize under Saline and Heavy Metal Stress through Application of Endophytic Fungal Strain SL3 and Exogenous IAA.

Modern irrigation practices and industrial pollution can contribute to the simultaneous occurrence of salinity and heavy metal contamination in large areas of the world, resulting in significant negative effects on crop productivity and sustainability. This study aimed to investigate the growth-promoting potentials of an important endophytic fungal strain SL3 and to compare its potential with exogenous IAA (indole-3-acetic acid) in the context of salt and heavy metal stress. The strain was assessed for plant growth-promoting traits such as the production of indole-3-acetic acid, gibberellins (GA), and siderophore. We selected two important crops, mung bean and maize, and examined various physiological and biochemical characteristics under 300 mM NaCl and 2.5 mM Pb stress conditions, with and without the application of IAA and SL3. This study's results demonstrated that both IAA and SL3 positively impacted the growth and development of plants under normal and stressed conditions. In NaCl and Pb-induced stress conditions, the growth of mung bean and maize plants was significantly reduced. However, the application of IAA and SL3 helped to alleviate stress, leading to a significant increase in shoot/root length and weight compared to IAA and SL3 non-treated plants. The results revealed that photosynthetic pigments, accumulation of catalase (CAT), phenolic contents, polyphenol oxidase, and flavanols are higher in the IAA and SL3-treated plants than in the non-inoculated plants. This study's findings revealed that applying the SL3 fungal strain positively influenced various physiological and biochemical processes in tested plant species under normal and stress conditions of NaCl and Pb. These findings also suggested that SL3 could be a potential replacement for widely used IAA to promote plant growth by improving photosynthetic efficiency, reducing oxidative stress, and enhancing metabolic activities in plants, including mung and maize. Moreover, this study highlights that SL3 has synergistic effects with IAA in enhancing resilience to salt and heavy stress and offers a promising avenue for future agricultural applications in salt and heavy metal-affected regions.

Incorporating cropping systems with eco-friendly strategies and solutions to mitigate the effects of climate change on crop production

Agricultural practices account for approximately 13.5% of all human greenhouse gas emissions and are a significant driver of land-use change. As a result, natural soil fertility has been dramatically reduced, impacting agricultural productivity, the environment, and human health. New technologies, such as green technologies, can address these challenges by adjusting agricultural practices. This paper reviews recent research on climate-mitigating agricultural practices in agronomic cropping systems, and to show how they affect crops, pests, and beneficial arthropods. An optimal amount of synthetic fertilizers and agrochemicals are necessary to maintain production costs, while maximizing outputs. There is a need to develop intelligent, responsive, biodegradable, and biocompatible materials to manufacture green, safe, and efficient fertilizers and pesticides. Site-specific nutrient management (SSNM), is an efficient strategy for managing nutrient efficiency. This system employs inorganic and organic supplies, geographical and temporal soil heterogeneity, crop demands of nutrients, and cropping techniques. A practical strategy to exploit the response of plants to abiotic factors, including the duration, extent, and incidence of specific tolerance mechanisms, is to deploy plant-based products (PBPs). Using microbials (MPBs) is a sustainable strategy to promote plant growth and productivity, even under abiotic situations. Further, nanoparticles, such as iron, silicon, silver, and titanium, can boost plant growth and physiological activity in wheat, maize, soybeans, and spinach are excellent alternatives to artificial chemical pesticides, as they are biodegradable and only affect the target species.Pest and predator responses to agricultural techniques require immediate intervention to mitigate against climate change and ensure food security.

The heat stress during anthesis and the grain-filling period of spring maize in Northeast China is projected to increase toward the mid-21st century.

Against the background of global warming, heat stress has become more frequent, which adversely affects the growth and development of spring maize plants in Northeast China. To adapt the regional maize production to climate change, it is imperative to understand the spatio-temporal characteristics of heat stress. In the present study, we analyzed three of the indices for heat stress, including the number of heat stress days, heating degree days (HDD, the total heat degree-days during critical stages), and the percentage of stations with heat stress. From 1981 to 2019, the number of heat stress days varied greatly among the study years, ranging from 0 to 14 and 27 days, respectively. The average HDD was 7.8 and 5.0 °C day from 1981 to 2000, respectively, and the main hot-spots of heat stress occurred in the southwest regions. Moreover, compared with 1981-2000, the region of HDD during anthesis higher than 10 °C day in 2041-2060 under the SSP1-2.6 and SSP5-8.5 climate scenarios increased by 9.1-50.1% and 0.1-28.6%. The average HDD during the critical stages from 2041 to 2060 increased under the SSP5-8.5 climate scenario, being 1.5 times higher than that during 1981-2000. HDD during maize anthesis and the grain-filling period showed an overall increasing trend with years. About 19% and 58% of the study locations showed heat stress during the past 39 years, respectively. Heat stress during anthesis and the grain-filling period for spring maize in Northeast China is projected to increase toward the mid-21st century. © 2023 Society of Chemical Industry.

Earthworm activity effectively mitigated the negative impact of microplastics on maize growth

Microplastic pollution can have detrimental effects on soil environments and inhibit crop growth. Earthworms, known as soil engineers, promote crop growth, but their role and impact on the amelioration of microplastic-polluted soil is not yet clear. In this study, we investigated the impact and pathways of earthworm activity on microplastic-contaminated soil by introducing varying densities (without earthworm:0, low-density: 1, medium-density: 2, high-density: 5 ind column−1) of earthworms (epi-endogeic) into soil contaminated with two types of microplastics: polyethylene and polyvinyl chloride. Our results showed that earthworms all survived in soil polluted with two types of microplastics. Meanwhile, earthworm activity increased nutrient content and enzyme activity by 0.2–36.1% and 2.9–34.3%, respectively, and significantly increased soil microbial biomass and community diversity index. Earthworm activity also decreased antioxidant enzyme activity and promoted maize plant growth, including agronomic traits such as plant height, biomass, root length, and root surface area. Furthermore, the nutrient content of maize organs increased by 1.1–29.7%. Partial least squares models confirmed that earthworm activity alleviated the stress effect of microplastic pollution on plant growth by improving soil structure, fertility, and microbial abundance and diversity. The greatest effect on maize growth was observed with the improvement of soil physical-chemical properties. Our results suggest that medium densities of earthworms have the greatest soil improvement effect and provide an important basis for bioremediation of farmland contaminated by microplastics and promoting green and efficient development in agriculture.

Evaluasi Arachis pintoi sebagai Biomulsa dalam Memperbaiki Kesuburan Tanah pada Pertanaman Jagung di Kemiringan Lahan yang Berbeda

Expanding agricultural land by using sloping dry land can be detrimental to the environment due to soil erosion and degradation. However, cover crops can be one of the technologies applied to reduce these risks. Arachis pintoi is one of cover crops that can be used as bio mulch on agricultural land. The study aimed to evaluate the effect of A. pintoi bio mulch on soil nutrient contents and maize plant growth at different slopes. A nested randomized block design was used in the study. Two levels of land used as the main factor and the type of mulch consisting of five levels (without mulch with weeding, without mulch without weeding, silver-black plastic mulch, straw mulch, and A. pintoi bio mulch) were used as the second factor. The results showed that A. pintoi bio mulch significantly increased the P content of the soil and could potentially increase several other macronutrients, especially C-organic, N, and Ca. The use of A. pintoi bio mulch with a cover technique that was left to cover the entire soil surface suppressed the growth and yield of maize plants compared to the control treatment.
 
 Keywords: cover crops, mulch, ornamental peanut, soil fertility, rice straw

Phosphate solubilizing rhizobacteria inoculation to increase rock phosphates efficiency and improve maize growth

Rock phosphates are less soluble and agronomically not as efficient as the acidulated. However, some rhizobacteria can improve the solubilization of inorganic phosphates in the soil, raising the efficiency of the rock phosphates. The objective was to evaluate the development of maize plants in response to the application of soluble and rock P sources associated with rhizobacteria inoculation. A greenhouse experiment was carried out with six P sources: no P application; ​​Triple Superphosphate (TSPh); Gafsa rock phosphate (reactive); Itafós rock phosphate (non-reactive); TSPh + Gafsa; and TSPh + Itafós, and three inoculation forms: no inoculation, Burkholderia pickettii GN 2214 and Pseudomonas sp. fluorescens group P21. Plant height, stem diameter, leaf area, shoot dry weight (ShDW), root dry weight (RDW), total dry weight, cumulative P content in ShDW, RDW/ShDW ratio and relative agronomic efficiency were assessed. Agronomic efficiency and growth of the TSPh-treated plants were better than of those treated with rock phosphates. The association of TSPh with rock phosphates increases the agronomic efficiency and maize plant growth more than the isolated rock sources. Inoculation with P. fluorescens strain P21, improved the performance of maize fertilized with Gafsa phosphate, but had no effect when associated with Itafós phosphate. Together with TSPh, inoculation intensified shoot and root growth, indicating the potential to increase the efficiency of soluble sources as well.

In vitro germination and growth of maize and lettuce seeds exposed to iron oxide magnetic nanoparticles

Iron is a micronutrient essential for optimal plant development, nevertheless, due to their low solubility it is poorly available to plants, affecting many agronomically important crops. Nanofertilizers are nanoparticles that have been used as an alternative for the release of micro and macronutrients necessary for plant nutrition. Therefore, in this research we evaluated the effect of the application of aqueous suspensions of iron oxide (magnetite-maghemite) nanoparticles stabilized with chitosan on the germination and growth of Maize (Zea mays L.) and Lettuce (Lactuca sativa L.) plants at in vitro level. Preliminary results suggest that for aqueous nanoparticle suspensions with iron contents below 50 ppm there is no evidence of negative effects on the seed germination process and on the growth of maize seedlings. Similarly, it was determined that there is no phytotoxic effect of the suspensions on Lettuce seeds.

Dynamics of soil nitrogen and N-cycling-related genes following the application of biobased fertilizers

Biobased fertilizers recovered from animal manure are sustainable substitutes for synthetic mineral nitrogen (N) fertilizers, showing high potential to minimize environmental pollution while maintaining nutrient supply. This study investigated the response of maize (Zea mays L.) and soil microbes to the application of biobased fertilizers, i.e., pig manure (PM), the liquid fraction of digestate (LFD), and evaporator concentrate (EVA) in replacement of calcium ammonium nitrate (CAN) in a 56-day pot experiment. Apart from maize plant growth and soil chemical properties, the abundance of N-cycling-related genes was determined by destructive sampling on days 8, 16, and 56 after fertilization. The detected gene copies of bacterial and archaeal amoA in the soil were significantly increased by N fertilization. Relatively high NH4+-N concentrations (37.5–62.5 mg kg−1 soil dry weight) applied in this experiment may have promoted gaseous N losses via nitrifier nitrification and nitrifier denitrification shortly (8–16 days) after fertilization. Consequently, net N loss was observed in all the fertilized treatments, however, biobased fertilizers resulted in lower N loss as compared to CAN. The presence of maize plants also reduced the N loss, probably driven by the continuous NO3−-N uptake which reduced the N source for denitrification. Overall, the application of PM and LFD revealed no significant difference with CAN regarding either plant growth or soil biochemical properties. Whereas the EVA application resulted in lower biomass and nutrient uptake in the young maize plant compared to other treatments, probably attributed to salt stress due to the imbalanced ratio of N and Na in this product.

Impact of N Supply on Some Leaf Characteristics of Maize Crop

Nitrogen (N) is an essential nutrient widely used in maize crop production. The application of a high N rate is commonly practiced by growers as a "guarantee" of optimal growth and yield. However, excessive nitrogen consumption can cause wastage, negatively impact plants, and adversely affects the environment. This paper reports on the impact of N supply on leaf characteristics in maize. Maize was grown in an experimental plot of the Department of Agronomy, The Hungarian University of Agriculture and Life Sciences, Hungary, during the spring and summer of 2021 (May - October). Four observation plots consisting of ​​102 m area size were evaluated for various N levels (0, 50, 100, and 150 kg ha-1 N a.i) with marked plants sampling in four replications. Data collection on leaf traits viz. leaf number plant-1 (B), leaf number plant-1 (S), temperature 0C (leaf surface), SPAD, leaf length (cm), leaf width (cm), and leaf area (cm2) were measured one week after application in weekly sequences of N until the eighth week. The results showed that nitrogen fertilizer application increased the leaf number plant-1 (B), temperature, SPAD, and leaf width while contrasting with leaf number plant-1 (S). However, there was no difference in leaf length for all treatments studied. Although an increase occurred up to the use of 100 N. Whereas, the 150 N treatment showed low performance and exhibited a negative correlation for all traits except temperature and number of leaves (S). The results suggest that treatment of 100 N produced the best results in most traits studied. Furthermore, a detailed research study is needed to confirm the findings, as many other environmental factors influence maize plant growth.

Growth promotion traits and emission of volatile organic compounds of two bacterial strains stimulate growth of maize exposed to heavy metals

Stress alleviation of plants grown in heavy metal contaminated soil has been observed after inoculation with plant growth-promoting bacteria. Here we analyzed individual and combined effects of Pseudomonas fluorescens UM270 and Bacillus paralicheniformis ZAP17 on plant growth of maize (Zea mays L.) subjected to stress through arsenic and mercury exposure. Both strains showed high and regular levels of tolerance to arsenic and mercury metals, respectively. Interestingly, plant growth promoter mechanisms, such as the production of 3-indolacetic acid, solubilization of phosphates, secretion of siderophores and biofilm formation, were maintained under the presence of the two metals, except for phosphate solubilization and the production of siderophores that were inhibited at certain concentrations. The metallic salts modified the mix of volatiles produced by UM270 and ZAP17, with the presence of ketones and aldehydes predominating. We also found compounds like 2-butanone, 2,3-butanediol and dimethyl disulfide, nonanal, hexadecanal, 2-tetradecanon and 2-tridecanone, which have been reported as plant growth promoters. Finally, the co-inoculation of the strains UM270 and ZAP17 in maize plants grown with different concentrations of metallic salts, showed that the presence of HAsNa2O4 stimulated shoot length and plant biomass, the trials with HgCl2 in the presence of the consortium presented a greater development of plant biomass, root and shoot length, while the combination of AsNaO2 and the bacterial consortium allowed to stimulate all the evaluated parameters, as compared with the control plants (without inoculation). These results demonstrate the importance of phytoremediation processes assisted by beneficial microorganisms, further is one of the first that has tried to link the emission of volatile organic compounds with a possible growth promotion effect in conditions of stress caused by heavy metals. In conclusion, the PGPB P. fluorescens UM270 and B. paralicheniformis ZAP17 exert multiple mechanisms of growth promotion, and they represent an excellent option as biopromoters in soils contaminated with heavy metals.

SERAPAN N, P, DAN K PADA JAGUNG MADURA-3 DI TANAH LEMPUNG LIAT BERPASIR DIAMELIORASI BIOCHAR DAN BENTONIT-TERAKTIVASI ASAM

Sandy clay loam soil in Bangkalan is a soil with a low content of nutrients, organic matter, bases, and cation exchange capacity (CEC), which inhibits the growth of maize plants. In addition, the nature of the soil causes the fertilizer to become more soluble, and the absorption of nutrients, especially potassium, is low. One of the efforts to increase potassium uptake in sandy loam soils is applying biochar and acid-activated bentonite. This study aimed to examine the effect of adding biochar and acid-activated bentonite to the nutrient uptake of maize plants in the sandy soil of Bangkalan. Biochar was prepared from maize cobs by the Kon-Tiki method; bentonite was activated by physical (200 oC) and chemical (1N H2SO4) methods. The greenhouse experiment was carried out using a completely randomized design with biochar (B) and acid-activated bentonite (T) as treatments, each with three levels, namely 0, 5, 10 t ha-1 and three replications. Soil analysis performed included pH, organic carbon, CEC and exchangeable bases, while plant tissue analysis included leaf height and area. The results showed that the combination of biochar and acid-activated bentonite significantly increased soil pH, soil exchangeable K, soil exchangeable Na, and leaf area of maize plants. A single application of biochar significantly increased soil organic C and maize plant height. The application of acid-activated bentonite significantly increased the CEC of sandy loam soils.

Effect of Arbuscular Mycorrhizal Fungi Application and Compost Fertilizer on the Growth and Production of Maize Plants (Zea Mays L.) on Yellow Red Podzolic Soil

The production of corn plants grown on yellow red Podsolik soil is still low due to low soil fertility. The purpose of this study was to see the effect of compost type and Arbuscular Mycorrhizal fungi application and their interaction on the growth and production of corn plants in yellow red podsolik soil. The study was a factorial experiment consisting of two factors, namely compost enriched with Trichoderma sp, EM4 compost and Arbuscular Mycorrhizal treatment in the form of factorials in a Randomized Group Design. The first factor is the application of compost and the second factor is the application of mycorrhiza, each of which consists of three levels. The results showed that the interaction between the treatment of compost fertilizer and without Arbuscular Mycorrhiza in corn plants only gave a real effect on plant height and 90% mycorrhizal infection, and the single factor of compost gave a real effect on the number of leaves 10.39 strands, stem diameter 0.66 cm, fruit weight without colobot 88.92 grams, biomass 122.00 grams and root weight 45.00 grams. The application of compost enriched with EM4 without the application of Arbuscular Mycorrhizal Fungi gave the best results for plant height, number of leaves, stem diameter, fruit weight without kolobot, root weight, biomass and root infection. While the compost treatment enriched with Trichoderma sp without the application of Arbuscular Arbuscular Mycorrhiza gave the best results for corn fruit weight.

Mitigation of heavy metal stress in maize (Zea mays L.) through application of silicon nanoparticles

The ability of silicon to increase plant resistance to abiotic stress is well recognised, but less well known is the ability of silicon nanoparticles (SiNPs) to diminish abiotic stress. In this study, therefore, we compared the effect of sodium silicate and SiNPs on plant growth, biomass, pigments, soluble protein, proline, oxidative stress, antioxidant enzymes, and Cd accumulation in maize grown in cadmium (Cd) contaminated soil in a pot experiment arranged in randomized complete block design. Soils were contaminated with varying concentrations of Cd (0, 25, and 50 mg/kg). SiNPs showed specific agglomerated structure having remarkable surface area for nutrients adsorption. Cd stress caused a significant reduction in agronomic attributes by enhancing oxidative stress. Conversely, foliar spraying of Si and SiNPs significantly overcomes the Cd-induced decline in maize plants. Si and SiNPs significantly enhanced the agronomic and physiological attributes of maize by upregulating the activities of SOD, POD, CAT, and APX and reducing the MDA and H2O2 contents under Cd stress. Si significantly reduced the Cd contents in grains by 60.6% (TE) and 43.2% (TF) under Cd 25 and 50 mg/kg stress, respectively, whereas SiNPs decreased the Cd contents in grains by 62.2% (TH) and 48.7% (TI) under Cd 25 and 50 mg/kg stress, respectively. It was noted that the individual delivery of Si and SiNPs had no statistically significant influence on the protective nature. Thus, foliar application of both forms of silicon might be helpful in enhancing plant resilience under Cd stress conditions.

Synergistic Effects of Kaolin and Silicon Nanoparticles for Ameliorating Deficit Irrigation Stress in Maize Plants by Upregulating Antioxidant Defense Systems.

Water deficit is a significant environmental stress that has a negative impact on plant growth and yield. In this research, the positive significance of kaolin and SiO2 nanoparticles in moderating the detrimental effects of water deficit on maize plant growth and yield is investigated. The foliar application of kaolin (3 and 6%) and SiO2 NPs (1.5 and 3 mM) solutions increased the growth and yield variables of maize plants grown under normal conditions (100% available water) and drought stress conditions (80 and 60% available water (AW)). In addition, plants treated with SiO2 NPs (3 mM) demonstrated increased levels of important osmolytes, such as proline and phenol, and maintained more of their photosynthetic pigments (net photosynthetic rate (PN), stomatal conductance (gs), intercellular CO2 concentration (Ci), and transpiration rate (E)) than with other applied treatments under either stress or non-stress conditions. Furthermore, the exogenous foliar application of kaolin and SiO2 NPs also reduced the amounts of hydroxyl radicals (OH), superoxide anions (O2), hydrogen peroxide (H2O2), and lipid peroxidation in maize plants experiencing a water deficit. In contrast, the treatments led to an increase in the activity of antioxidant enzymes such as peroxidase (POX), ascorbate peroxidase (APX), glutathione peroxidase (GR), catalase (CAT), and superoxide dismutase (SOD). Overall, our findings indicate the beneficial impact of the application of kaolin and silicon NPs, particularly the impact of SiO2 NPs (3 mM) on managing the negative, harmful impacts of soil water deficit stress in maize plants.

Mixed Consortium of Salt-Tolerant Phosphate Solubilizing Bacteria Improves Maize (Zea mays) Plant Growth and Soil Health Under Saline Conditions.

The rhizobacterial isolate SP-167 exhibited considerable phosphate solubilization, IAA production, exo-polysaccharides, proline, APX, and CAT at a concentration of 6% NaCl (w/v). 16S rDNA sequencing and BLAST analysis showed that isolate SP-167 was Klebsiella sp. In this study, T2 and T8 consortium was developed on the basis of the compatibility of isolate SP-167 with Kluyvera sp. and Enterobacter sp. At 6% NaCl (w/v) concentration, T2 and T8 showed increased PGP properties such as phosphate solubilization, IAA, Proline activity, CAT, POD, and EPS than isolate SP-167. The maximum increase in shoot length was recorded in T2-treated maize plants as compared to the control after 60days in 1% NaCl stress. The N, P, and K content of leaves were significantly increased in maize plants with the inoculation of both the T2 and T8 consortium. The electrical conductivity of soil was decreased significantly in the T2 inoculated 1% NaCl (w/v) treated pot after 30, 60, and 90days. In this study, soil enzymes DHA and PPO were significantly increased in both T2 and T8 treated combinations. The Na concentration in root and shoot were significantly decreased in T8 inoculated plant than in T2, as confirmed by the translocation factor study.

Comparative Evaluation of Fe-Impregnated Filter Paper and Some Conventional Phosphorus Extractants for Assessing Phosphorus Availability in Some Amended Soils of Southwest Nigeria

ABSTRACT Iron-impregnated filter paper (Fe-Pi) was evaluated as phosphorus (P) extractant in four soils of Ogun state, southwest Nigeria in a screenhouse experiment. The experiments lasted for 8 weeks. Soil P contents were extracted at 0, 4, and 8 weeks after the incorporation of amendments (cattle manure, poultry manure, and wood ash) using Fe-Pi, Bray-1, Bray-2, Mehlich-1, Hunter, and Olsen extractant. Agronomic variables were taken fortnightly from grown maize plants and later harvested at 8 weeks, residual effects of the treatments were also evaluated. Maize dry matter weight (DMW) and P uptake were also measured. Results indicated that a linear relationship existed among the extractants with significant coefficient at p ≤ .001. Fe-Pi established a strong relationship with the conventional extractants in the following order: Bray-1 (R 2 = 0.99) > Bray-2 (R 2 = 0.98) > Hunter (R 2 = 0.96) > Mehlich-1 (R 2 = 0.86) > Olsen (R2 = 0.82). Fe-Pi had a significant relationship with P uptake and DMW. Phosphorus uptakes under the animal manure amendments were statistically higher than uptake in control and woodash amended soils. Therefore, the study concluded that Fe-Pi was a good predictor of plant available P and had significant relationship with Bray-1, thus it could be considered for the estimation of soil available P in soils of southwest Nigeria.

Application of special fertilizers and their effects on the agronomic aspects of maize and soil fertility

Maize has a high nutritional requirement, especially regarding NPK fertilization. However, conventional fertilization with these nutrients presents a high loss potential, mainly by volatilization, leaching, adsorption, and fixation, which may reflect on the development and yield of maize plants. Using fertilizers with increased efficiency seeks to mitigate these limitations, reducing potential losses due to gradual nutrient release. This study aimed to compare the nutrition, growth, and production of maize plants subjected to different doses and special NPK fertilizers fully applied at planting and their residual effect on the soil. It was a randomized block design in a 3x4 factorial scheme with four replications. The first factor consisted of conventional mineral, polymer-coated, and organomineral + PGPB fertilizers. The second factor included doses of 0, 60, 90, and 120 kg ha-¹ of NPK. The study evaluated vegetative growth, foliar nutrition (N, P, and K), yield growth components, productivity, profitability, and residual K content in the soil after cultivation. The conventional mineral fertilizer produced more dry biomass in the aerial part. Profitability was similar between conventional and special fertilizers. However, the latter performed better overall in vegetative and productive growth, showing a potential reduction of the applied doses without compromising grain yield, especially in organomineral + PGPB fertilization. This treatment also presented a higher residual effect of K on the soil.

Maize LSC encoding a large subunit of ribonucleotide reductase is required for subsidiary cell development and plant growth.

The four-celled stomatal complex consists of a pair of guard cells (GCs) and two subsidiary cells (SCs) in grasses, which benefits fast adjustment of stomatal pore aperture. The formation and development of SCs are thus important for stomatal functionality. Here, we report the maize loss of subsidiary cells (lsc) mutant with a large number of stomata lacking one or two SCs. The loss of SCs is supposed to be resulted from impeded subsidiary mother cells (SMC) polarization and asymmetrical division. Besides the defect in SCs, the lsc mutant also displays a dwarf morphology and pale and stripped newly-grown leaves. LSC encodes a large subunit of ribonucleotide reductase (RNR), an enzyme involved in deoxyribonucleotides (dNTPs) synthesis. Consistently, the dNTPs levels and expression of genes involved in DNA replication, cell cycle progression, and SC development were significantly reduced in the lsc mutant compared with the wild-type B73 inbred line. Conversely, overexpression of maize LSC increase dNTP synthesis and promotes plant growth in both maize and Arabidopsis. Our data indicate that LSC regulates dNTP production and is required for SMC polarization, SC differentiation, and plant growth.