Effect Of Plant Population Research Articles

Trade-offs and adaptation to metalliferous soils: The role of soil microbiome in metal tolerance and uptake in Arabidopsis halleri ecotypes from a reciprocal transplant experiment.

Soil contamination with trace metal elements is a worldwide issue, prompting research on plant species capable of hyperaccumulating metals to reduce soil toxicity. Previous research suggests that both plant species and their populations can affect soil microbial communities, yet little is known about how different populations of hyperaccumulator species influence these microbial communities to enhance metal-uptake and tolerance. This study evaluated the effect of soil origin, soil microbiome, and plant population on phytoextraction efficiencies of Cd and Zn among four A. halleri populations: two each from metalliferous and non-metalliferous sites. In a controlled transplant experiment, clonal replicates of A. halleri were grown in native and three non-native soils for six months. Biogeochemical analyses of plants and soils were conducted, alongside sequencing of root-associated soil bacterial/archaeal and fungal DNA. Soil treatments primarily differed in pH, total Cd, Pb, and Zn, as well as acid and alkaline phosphatase enzyme activities. A combined effect of soil origin and population was noted for arylsulfatase and β-glucosidase activities, as well as ammonium and nitrate concentrations. Both non-metallicolous and metallicolous populations accumulated high levels of Cd and Zn in metalliferous soils with the non-metallicolous population NM_PL14 outperforming the metallicolous populations in Zn hyperaccumulation. Interestingly, non-metallicolous populations grown in metalliferous soils exhibited no trade-offs in plant performance despite higher Cd and Zn accumulation. Soil origin had a stronger effect on the bacterial/archaeal and fungal community composition than plant ecotype. Partial least square regression models explained 66 % and 79 % of the variability in A. halleri Cd and Zn hyperaccumulation. There was a positive association between Zn-uptake and specific microbial taxa (e.g., Cornebacteriales, Microbacteriaceae, Propionibacteriales, Rhizobiaceae, Basidiomycota, Oidiodendron, Phallaceae) and functional activity (e.g., arylsulfatase, S oxidation) in metalliferous soils. Taken together, our findings suggest that non-metallicolous A. halleri populations may be better suited for Zn phytoextraction applications.

Substitutive Effects of Upland Rice and Soybean Plant Populations on the Performance of the Component Crops in Intercropping System

Substitutive Effects of Upland Rice and Soybean Plant Populations on the Performance of the Component Crops in Intercropping System

Effect of refugia plant (Zinnia sp.) population on the presence of stem borer (Scirpophaga innotata Walker) and natural enemies in rice

Abstract. Olsiviana, Yassi A, Melina. 2024. Effect of refugia plant (Zinnia sp.) population on the presence of stem borer (Scirpophaga innotata Walker) and natural enemies in rice. Biodiversitas 25: 2652-2660. This study supports biological control by preserving natural enemies in rice cultivation through habitat modification. The research aimed to analyze the effects of different population levels of refugia (Zinnia sp.) on pest attack rates, the presence and diversity of natural enemies of rice stem borer (Scirpophaga innotata Walker 1863), and rice (Oryza sativa L.) production. The study was designed using a Randomized Group Design (RGD) with four population treatment levels: control (no Zinnia sp.), sparse population (32 polybags of Zinnia sp.), medium population (96 polybags of Zinnia sp.), and dense population (160 polybags of Zinnia sp.). The results showed that the dense population (160 polybags of Zinnia sp.) produced the lowest stem borer infestation rate in the eighth week of observation (1.67%). Pests in all treatments belonged to four orders: Lepidoptera, Hemiptera, Coleoptera, and Diptera, with Hemiptera being the most prevalent. Natural enemies of rice pests belonged to three orders: Coleoptera, Hymenoptera, and Orthoptera. The dense population treatment (160 polybags of Zinnia sp.) yielded the highest values for diversity index (H') at 2.1785, species richness index (R) at 2.1837, and evenness index (E) at 0.9915. This treatment also achieved the highest average rice production at 8.64 tons/ha. Meanwhile, the highest dominance value (C) of 0.2489 was found in the control treatment. Thus, this study supports the idea that increasing the population of Zinnia sp. as a refugia plant can increase the diversity of natural enemies, reduce rice stem borer infestation, and increase rice plant production.

EFFECTS OF PLANT DENSITY ON MICRONUTRIENT UPTAKE IN SUNFLOWER (Helianthus annuus L.) VARIETIES

The objective of this study was to determine the effects of plant population per unit area on micro nutrients (Fe, Cu, Zn, Mn, B) uptake of some sunflower genotypes. Three sunflower varieties (Sanay MR, Oliva CL and LG5543 CL) were used as genetic material and three different plant populations: 40800, 57100 and 95200 plants/ha (sowing spacing; 0.35 x 0.70, 0.25 x 0.70 and 0.15 x 0.70 m, respectively). According to the results, the micronutrient concentrations as well as the seed and oil yields and partly also oil content increased significantly as the plant population increased. For all analysed micronutrients, the highest concentration has been obtained with 95200 plant ha-1. Micronutrient elements as well as seed and oil yields differed according to plant density and cultivars. Among the varieties, LG 5543 CL more effected by plant population had the highest micronutrient concentration, seed yield and oil yield. As a result, a high plant population (95,200 plant ha) with the highest micronutrient content and also the highest seed and oil yield could be recommended for Mediterranean environments with a semi-humid climate. However, optimum plant density was found differently according to varieties and years.

Effect of plant population on growth and yield of okra [Abelmoschus esculentus (L). Moench] under Kymore plateau of Madhya Pradesh

Effect of plant population on growth and yield of okra [Abelmoschus esculentus (L). Moench] under Kymore plateau of Madhya Pradesh

Effects of sheep manure, plant population and nitrogen levels on growth and fresh fruit yield of chilli pepper (<i>Capsicum frutescence</i> l.) at Samaru, Zaria, Nigeria

Field experiments were conducted between 2004 and 2006 at the Institute for Agricultural Research Farm, Samaru Zaria in the Northern guinea savannah ecological zone of Nigeria, to study the response of chilli pepper (Capsicum frutescence L.) to sheep manure, plant population and nitrogen levels. Treatments evaluated consisted of four levels of sheep manure rates (0 t, 5 t, 10 t, and15 t ha-1), three plant populations (22,222; 44,444; and 66,666 plants ha1) and four rates of Nitrogen (0kg,60kg 120kg and 180 kg N ha1). The treatments were laid out in a split plot design and replicated three times. Result showed that application of sheep manure produced about significant increase in number of branches by 80%, similarly number of fruits increased by more than 600% and fresh fruit yields (Kg ha-1) recorded 57% increase over the control. Plant population was observed to significantly increase in the number of fruits per plant with 22,222 and 44,444plant/ha recording similar values, but higher number of fruits produced per plant than 66,666 plants ha-1 However, fresh fruit yield of Chilli pepper was not significantly influenced by plant population. The use of 120kgN ha1 resulted in increased number of branches, fruit per plant and fresh fruit yields by 57 and 60% respectively over non fertilized plants. Application of sheep manure at 10 t ha1, +44,444plants ha and 120kgN ha could be recommended for the production of chilli pepper under rain fed condition in Northern Guinea savannah.

NPK Fertilizer Test and Plant Population on The Growth And Years of Sorgum (Sorghum bicolor (L.) Moench)

This study aims to determine the effect of NPK fertilizer dose and plant population on the growth and yield of Sorghum (Sorghum bicolor (L.) Moench).The design that was carried out was a Complete Randomized Block Design (RAKL) Factorial consisting of NPK fertilizer dose treatment with four levels and the second-factor Spacing with two levels, so there are eight treatment combinations repeated four times. The data obtained were analyzed by analysis of variance and to find out significant differences continued with Duncan's Multiple Range Test with a significant level of 5%. The results showed that the fertilizer dose treatment had a significant effect on plant height and seed weight per panicle, the plant population treatment had no significant effect on all observed parameters, and the combination of fertilizer dose and population treatments had no significant effect on all observed parameters. The treatment with a fertilizer dose of 300 kg/ha produced the highest seed weight per panicle of 91.79 gr, and the lowest fertilizer dose of 150 kg/ha produced a seed weight per panicle of 71.95 gr.

Profitability of Zero Tillage Wheat in Rice Fallows under National Innovation on Climate Resilient Agriculture Project at Chhattisgarh Plain Zone Durg in India

The research evaluated the economics of producing wheat under national innovation on climate resilient agriculture adopted village named karga using zero tillage and conventional method, and it evaluated how much technology and inputs contributed to the higher productivity brought over by zero tillage (ZT). The study found that zero tillage technology is able to increase farmers' profitability and aid in resource conservation. The difference in gross returns between zero tillage and conventional tillage approaches has been divided into 45% related to zero tillage and the remaining due to changes in input costs. This shows that zero tillage practices resulted in better performance in Rabi 2022- 2023 seasons, with an average yield increase of 7.7%. Net income per ha was Rs. 12475 with a reduced cost of cultivation due to reduced number of irrigations and lessened sowing operations cost. Higher yield is due to timely sowing, healthy crop growth, good plant population and less effect of climatic hazard.

Crop management options to help increase maize grain carotenoid levels

Despite breeding advancements in high carotenoid maize, impacts of common crop management on carotenoid levels remain unclear. Our objective was to identify possible crop management options, other than genotype selection, for increasing maize grain carotenoid concentration and to relate them with the resulting flour color. We were also interested in understanding what environmental factors help explain variations in grain carotenoid concentration. The effects of plant population, sowing date, genotype selection, and N fertilization on total grain carotenoid concentration and flour color were tested in different field experiments under rainfed conditions. Genotypes had 25% higher values when sowing date was delayed. However, the response to sowing date was genotype dependent (p < 0.05; an increase from 6 to 57%). Plant populations higher than 8.5 plant m-2 decreased carotenoid concentration by 5% (p < 0.05), while N fertilization showed inconsistent effects (+5 or −12% depending on the environment). The higher concentrations in later sowings were associated with cooler temperatures and a better water balance during grain filling. The impact of management over carotenoid concentration also affected the resulting flour color, modifying its lightness and chromaticity. Results suggest that, in addition to genotype selection, late sowing dates and moderate plant populations can help increase grain carotenoid concentrations.

Effect of plant population and row orientation on crop yield under sorghum-cowpea intercropping systems in semi-arid Zimbabwe

Smallholder farmers commonly practise intercropping to improve crop yield per unit land area. Proper combination of plant population and row orientation of the component crops needs to be established and this prompted this investigation. A 2x7 factorial experiment was laid in a RCBD with three replications, at Matopos Research Station in Natural Region IV of Zimbabwe. Treatments consisted of sorghum planted at a constant population of 55556plants/ha intercropped with cowpea (C) simultaneously planted at varying populations of 111111plants/ha (C1), 166667plants/ha (C3) and 222222plants/ha (C3) in East-West (EW) and North-South (NS) row orientation. Interaction of cowpea population density and row orientation significantly (p&amp;lt;0.05) influenced crop yield and its attributes. Treatment NS-SC3 produced lowest number of pods/plant and grains/pod of 2.6 and 6.1 respectively. Highest cowpea grain yield (637.2kg/ha) was obtained in EW-C3 and lowest (92.4kg/ha) in EW-SC3. Sorghum yield was highest in NS-S (1296.5kg/ha) and lowest in EW-SC3 (491.9kg/ha). LER showed that intercropping performed better than sole crops except for EW-SC3 and NS-SC3 which had LER of 0.800 and 0.905 respectively. Highest LER of 1.312 was obtained in EW-C2. Farmers should plant sorghum-cowpea intercrops in EW row orientation for increased cowpea grain yield but NS row orientation for sole sorghum.

Growth and Yield of Local Upland Rice (Oryza sativa L.) Wakawondu Cultivar in Various Plant Populations and Balanced Fertilization

The present study aimed to analyze the effect of plant population and fertilization based on efficiency and nutrient adequacy balanced between organic and inorganic on the growth and yield of local upland rice Wakawondu cultivar. The treatment design was split-plot in a randomized block design with three replications. The main plot was the number of seeds per planting hole (A) consisting of three levels, namely one seed (A1), two seeds (A2), and three seeds per planting hole (A3). Subplots were organic and inorganic fertilization (B) which consists of four levels, namely without fertilization (B0), 100% bokashi from Cromolaena odorata or 10 tons ha-1 (B1), giving 100 % inorganic fertilizer or Urea 200 kg ha-1, SP-36 100 kg ha-1, KCl 100 kg ha-1 (B2), and a combination of 50% bokashi fertilizer or 5 tons ha-1, and 50% inorganic fertilizer or Urea 100 kg ha-1, SP-36 50 kg ha-1, KCl 50 kg ha-1 (B3). Plant height, number of leaves, leaf area, productive and maximum of tillers, harvesting age, flag leaf area, length of panicle, total number of grains, percentage of open grain, grain weight of 1000 grains, dry grain weight, and yield were the variables observed. Data were statistically analyzed using ANOVA and further DMRT α= 0.05. The results showed that three seeds per planting hole were the best treatment to increase the number of productive tillers, namely 7.8 tillers with a production of 1.52 tons ha-1 or an increase in productivity by 5% compared to one seed per planting hole. A balanced fertilization combination of organic and inorganic fertilizers is the best treatment that can increase the number of productive tillers, namely 7.1 tillers with a production of 1.8 tons ha-1 or an increase in productivity of 16% compared to without fertilization.

Effects of radiation and plant population on growth and yield attributes of wheat

Radiation plays a crucial role for growth and yield of wheat. A field experiment was conducted at the Field Laboratory of Agrotechnology Discipline of Khulna University in Bangladesh during November 2018 to March 2019 to study the effect of radiation levels and plant population on growth and yield attributes of wheat. The study was set out in the randomized complete block design with four radiation levels (full sunlight, 75% light, 55% light, 25% light) and three plant population densities (160 plant/m2, 200 plant/m2, 230 plant/m2) that replicated thrice. Growth and yield attributes of wheat were generally similar between two light levels (full sunlight, 75% light) and two plant densities (200 plant/m2, 230 plant/m2). However, the attributes were usually minimum at 25% light. The interaction effect of full sunlight or 75% light with optimal (200 plant/m2) or maximal (230 plant/m2) plant densities produced statistically similar plant height, leaf number, tiller number, total dry matter, grain yield, straw yield, and biological yield. Therefore, combination of 75% light with 230 plant/m2 is suggested for growing wheat in light limited areas and in agroforestry system with acceptable yield.

DRY MATTER ALLOCATION AND GRAIN YIELD OF WHEAT AS INFLUENCED BY SOLAR RADIATION LEVEL AND PLANT DENSITY

An experiment was conducted from November 2018 to March 2019 to identify the effect of radiation levels and plant population on dry matter allocation and yield of wheat with the variety ‘BARI Gom 25’. The study was set out in the Randomized Complete Block Design with four radiation levels (full sunlight, 75% light, 55% light and 25% light) and three plant densities (160 plants m-2, 200 plants m-2, 230 plants m-2) that replicated thrice. Full sunlight or 75% light in combination with optimal plant density (200 plants m-2) resulted maximum culm dry weight, leaf dry weight, spike dry weight and total dry matter weight plant-1. The numbers of filled grain and unfilled grain plant-1 and yields of grain and straw m-2 were the highest from the above-mentioned combination. The lowest dry weights for culm, leaf, spike, and total dry matter and minimum grain yield and straw yield were obtained from 25% light either alone or in combination with any plant densities indicating the profound influence of light on dry matter production and grain yield of wheat. Therefore, reduced light (up to 25%) and optimal plant density can ensure wheat production without significant yield loss. This finding suggests possibility of wheat cultivation in agroforestry system and light limiting areas in Bangladesh and other parts of the world.

Live soil inocula, not host population or domestication status, is the predominant driver of growth benefits to cowpea

PurposeCrops rely on microbes for critical services, but host benefits can be influenced by local makeup of microbiota and the host’s capacity to select optimal strains. We investigated host benefits that cowpeas receive from microbiota depending on plant genotype, their domestication status, and soil source.MethodsWe performed a full factorial soil inoculation experiment. Twenty diverse cowpea genotypes, selected from wild and domesticated populations, were exposed to soil rinsates from four agricultural sites across California, all having cowpea cultivation and varied physicochemical features. Cowpea investment in and benefit from microbiota was quantified by measuring host growth response to inoculation, nodulation, and segregating trait variation.ResultsVariation in induction of root nodulation and strikingly heterogenous benefits to host growth were observed among soil sites. These effects were restricted to live soil inocula but were absent in autoclaved soil controls that lacked microbiota. Cowpeas expressed heritable variation in nodulation, but there was negligible effect of plant population or domestication status on the net benefit that hosts gained from microbiota.ConclusionSoils varied substantially and consistently among cultivation sites and were the most prominent driver shaping host growth effects on cowpeas. While growth benefits vary among host cultivars, soil microbiota (and the conditions that maintain them) predominantly shape plant performance in agricultural settings.

Response of upland rice variety to plant population under the low land agro-ecology of Bench Sheko Zone, South-west Ethiopia

Plant population has a strong influence on rice yield. A field experiment was conducted during the 2017 and 2018 main cropping seasons at Guraferda district in Bench Sheko Zone, Southwest Ethiopia. The objective of this study was to determine the optimum plant population and appropriate variety on grain yield and yield components of upland rice. The experiment was carried out using RCBD with three replications. Five levels of plant populations (60, 80, 100, 120, and 140 kg ha-1) and three levels of genotypes (Nerica-4, Suparica-1, and Local check) were studied. The main effect of plant population and variety had significant (p&lt;0.05) for most of the parameters investigated. However, the interaction effect had only statistically significant for the number of tillers, panicles, and grain yield. The combined results showed that the maximum grain yield of 5553.3, 5491.0, 5252.5, 5047.6, 5043.1, and 4955.6 kg ha-1 were obtained at the respective treatment combinations of Suparica-1 with 80, Suparica-1 with 100, Local check with 140, Suparica-1 with 120, and Local check with 120 and 100 kg ha-1 plant populations. In addition to the above result, a Partial budget analysis was also carried out to determine the economic optimum plant population for production. Accordingly, the combination of Suparica-1 at the rate of 80 kg ha-1 was appropriate to get a better yield and higher economic benefit. Therefore, it can be possible to suggest the finding for wider production. Int. J. Agril. Res. Innov. Tech. 12(1): 94-100, June 2022

Effects of plant density, seed spacing, and seed treatment on thrips injury to cotton

Previous observations in small-plot field trials in Tennessee suggest that thrips injury is higher in plots with lower plant densities and when singular plants are spatially isolated and uniformly distributed compared to a group of plants that are clumped together; however, research documenting this is limited. Thus, studies were performed in Jackson and Milan, TN across two years (2020, 2021). Both studies had fungicide-treated seed planted with or without an imidacloprid insecticide seed treatment. The first study investigated the effects of plant density by planting seed at rates considered to be low, normal, high, and very high. The second study investigated the effects of seed placement strategies with seed planted at the same density. Cotton plates were used to plant seed to result in singular plants that were spatially isolated and uniformly planted or clumped, “hill-dropped” plants. Results from the plant density tests showed thrips injury ratings were higher as the plant density decreased. At two test sites, the number of adult thrips was higher in plots with lower plant densities, indicating that thrips were more concentrated on individual plants. However, high thrips pressure and unfavorable growing conditions at the other sites seemed to overwhelm the potential effects of plant populations. Results from initial thrips injury ratings in the seed spacing study showed significantly higher injury for singular, uniformly distributed plants than plants in a hill (i.e., cluster); however, additional research is needed because one test was lost. Future research evaluating oviposition rates on recently emerged seedlings could help explain why decreased thrips injury occurs when plant densities are relatively high.

Response of Different Levels of Nitrogen and Plant Population to Grain Yield of Winter Hybrid Maize in Chitwan Valley

A field experiment on “Performance of hybrid maize under different levels of nitrogen and plant population” was conducted in Randomized complete block design (RCBD) at the research farm of the National Maize Research Program (NMRP), Rampur, Chitwan during the winter season of 2015/16 to determine the optimum level of nitrogen and plant population for winter season hybrid maize. The grain yield (2.38 Mt ha-1) obtained in control without nitrogen was significantly lower in comparison to its all other levels (70, 140 and 210 Kg N ha-1). Moreover, grain yield (5.45 Mt ha-1) produced by the application 210 Kg N ha-1 was significantly superior over 70 Kg N ha-1 (3.83 Mt ha-1) but remained at par with 140 Kg N ha-1 (5.02 Mt ha-1) which also differed significantly. Moreover, the grain yield (4.98 Mt ha-1) recorded with the population of 101010 plants ha-1 was significantly superior over 55,555 (3.34 Mt ha-1) and 69,444 (3.90 Mt ha-1) plants ha-1 but similar to that of 85,470 plants ha-1 (4.46 Mt ha-1) which was also significantly higher as compared to 69,444 and 55,555 plants ha-1 which were at par with each other. Regression analysis for the effect of nitrogen and plant population on grain yield showed the grain yield was 145 Kg N ha-1 and plant population was 87445 plants ha-1. Thus, hybrid maize (RML95/RML96) can be successfully grown by applying 145 Kg N ha-1 and maintaining a population of 87 thousand plants ha-1 to achieve a higher grain yield during the winter season.

滨海湿地植物种群Allee效应驱动机制研究进展

Allee效应是指生物个体适应度与种群规模或密度之间呈正向关联的现象, 因与植物种群动态和种群灭绝密切相关而受到生态学家的普遍重视。阐释多重胁迫下滨海湿地植物种群响应机制, 从保护生物多样性和维持生态系统稳定性层面发展系统性生态修复措施成为相关研究关注的重点。本研究分别从遗传过程、花粉扩散过程和生物互作关系不同层面, 总结分析了植物种群Allee效应驱动机制的研究进展。一方面, 植物因遗传过程中近交衰退、遗传变异丧失、有害突变累积等遗传结构改变造成繁殖失败而引发Allee效应；另一方面, 植物花粉扩散过程和动植物互作关系影响下的花粉限制也通过影响植物种群繁殖力成为驱动Allee效应的关键因素。滨海湿地水盐梯度变异及格局破碎化影响下, 植物种群遭受Allee效应的风险需引起关注, 维持滨海湿地植物种群适宜分布格局和生物连通过程成为缓解Allee效应的重要手段。结合生理学与化学生态学研究手段和长时间尺度动态监测技术, 有助于进一步阐释环境及生物等多重胁迫下Allee效应的非线性驱动机制。;Allee effect, the positive association between individual fitness and population size or density, has attracted more attentions from ecologists because of its closely relationship with plant population dynamics and population extinction. By explaining Allee effect of plant population under multiple stresses, developing systematic ecological restoration measures based on the biodiversity protection and ecosystem stability has become the focus of relevant research. This study systematically summarized the research results of different driving mechanisms of Allee effect in plant population in coastal wetlands based on genetic process, pollen dispersal process and plant-pollinator interaction. On the one hand, Allee effect was driven by reproductive failure due to genetic structure changes, such as inbreeding depression, genetic variation loss, and harmful mutations accumulation in the genetic process. On the other hand, Allee effect was caused by changes in plant population fecundity due to pollen limitation, which was affected by pollen dispersal process and plant-pollinator interaction. In the context of water and salt gradient variation and pattern fragmentation in coastal wetlands, it is conspicuous for the risk of Allee effect on plant population. It is important for alleviating Allee effect of plant population in coastal wetlands through providing suitable habitat, ensuring biological connectivity, and constructing population patches. Combination of physiological and chemical ecological research methods as well as long-term dynamic monitoring will help to further explain the nonlinear driving mechanism of Allee effect under multiple environmental and biological stresses.

PENGARUH POPULASI TANAMAN DAN DOSIS BIOFERTILIZER EXTRAGEN TERHADAP PERTUMBUHAN DAN HASIL TANAMAN WORTEL (Daucus carota L.) DI DATARAN RENDAH

A research with an aim to determine the effect of plant population, rate of biofertilizer ExtraGEN and their interaction on the growth and yield of carrot (Daucus carota L.) plants on the lowland was conducted. The experiment was carried out in the University of Mataram experimental field located in Narmada, West Lombok, NTB at an altitude of 136 m above the sea level from May to July 2019. The research used a Completely Randomized Factorial Design, consisting of 2 factors, namely the plant population and rate of biofertilizer ExtraGEN. The plant population consisted of 3 level : 1 plant/polybag, 3 plants/ polybag and 5 plants/polybag. The rate of biofertilizer ExtraGEN consisted of 4 levels: without biofertilizer ExtraGEN (control), with 100 ml/polybag biofertilizer ExtraGEN, with 200 ml/polybag biofertilizer ExtraGEN, and with 400 ml/polybag biofertilizer ExtraGEN. The combinations resulted in 12 interactions which were repeated 5 times. The data obtained were analyzed using Analysis of Variance (ANOVA) at 5 % significant level and followed by an Honestly Significant Difference (HSD) at the same level. The results showed that plant population affected the rate of increase in the length of petioles, total fresh weight of the roots/polybag and total dry weight of roots/polybag, but did not affect other parameters. Higher the plant population, lowered the rate of increase in length of the petioles increased the total weight of fresh roots biomass/polybag and the weight of total dry biomass/ploybag. Biomass weight per plant was obtained 4,07 g population of 1 plant/polybag, 1,37 g population of 3 plants/polybag and 0,56 g population of 5 plants/polybag. The rates of biofertilizer ExtraGEN did not affect the growth and yield of carrot plants on the lowland.

Effect of Blended (NPSB) Fertilizer Rates and Plant Population on Yield and Yield Components of Maize (Zea mays L.) at Bako, Oromia National Regional State, Ethiopia

Maize (Zea mays L.) is the major cereal crop in Ethiopia and plays a crucial role in ensuring food security. However, its productivity is constrained by a number of problems, among which use of high or low plant population and poor soil fertility management are the most critical once. Therefore, a field experiment was undertaken to determine the optimal NPSB fertilizer rate and plant population for maize at Bako. The experiment was laid out in split plot design distributing three levels of plant population [53,333 plants ha -1 (25 x75 cm), 66,666 plants ha -1 (60x25cm) and 76923 plants ha -1 (65x20cm)] in the main plots and five levels of NPSB fertilizer rates (0,100,150,200 and 250 kg NPSB ha -1 ) and recommended NP rates as sub-plots. The interaction of plant population and NPSB rates influenced significantly (P&lt;5 %) leaf area index, number of cobs plot -1 , number of kernel cob -1 , dry biomass and thousand kernel weight. The highest leaf area index 6.661 was recorded on the combination of 66,666 plants ha -1 with 200 kg NPSB fertilizer rate. The highest number of cob plot -1 (115.3) and dry biomass yield 28,299 kg ha -1 were recorded from 66,666 plant ha -1 with 150 kg NPSB ha -1 , and 53,333 plant ha -1 with standard check 92/69 kg NP ha -1 , respectively. The highest grain yield 9954 kg ha -1 with net profit of 76,038 Birr with marginal rate of return 598% was obtained from 150 kg NPSB ha -1 with 66666 plants ha -1 (60 cmx25 cm). Therefore, application of 150 kg NPSB ha -1 with 66666 plants ha -1 for farmers in the study area and with similar agro-ecology can use and can improve maize productivity. However, the experiment need to be further verified in multi-locations for better usage at different agro-ecologies. Keywords: plant population, blended fertilizer, maize, yield DOI: 10.7176/JNSR/12-21-04 Publication date: November 30 th 2021