scholarly journals Modeling Maize Canopy Morphology in Response to Increased Plant Density

2021 ◽  
Vol 11 ◽  
Author(s):  
Liang He ◽  
Weiwei Sun ◽  
Xiang Chen ◽  
Liqi Han ◽  
Jincai Li ◽  
...  

Increased plant density markedly affects canopy morphophysiological activities and crop productivity. This study aims to model maize canopy final morphology under increased interplant competition by revising a functional–structural plant model, i.e., ADEL-Maize. A 2-year field experiment was conducted at Mengcheng, Anhui Province, China, in 2016 and 2018. A randomized complete block design of five plant densities (PDs), i.e., 4.5, 6, 7.5, 9, and 15 plants m–2, with three replications was applied using a hybrid, i.e., Zhengdan 958. Canopy morphology at different PDs was measured with destructive samplings when maize canopy was fully expanded. The relationship of changes of organ morphology in relation to increased plant density was analyzed based on 2016 data. The ADEL-Maize was first calibrated for the hybrid at 4.5 plants m–2 and then revised by introducing relationships identified from 2016 data, followed by independent validation with 2018 field data. A heatmap visualization was shown to clearly illustrate the effects of increased plant density on final morphology of laminae, sheaths, and internodes. The logarithmic + linear equations were found to fit changes for the organ size versus increased plant density for phytomers excluding ear position or linear equations for the phytomer at ear position based on 2016 field data. The revision was then further tested independently by having achieved satisfactory agreements between the simulations and observations in canopy size under different PDs with 2018 field data. In conclusion, this study has characterized the relationship between canopy morphology and increased interplant competition for use in the ADEL-Maize and realized the simulations of final size of laminae, sheaths, and internodes, as affected by increased plant density, laying a foundation to test an ideotype for maize withstanding high interplant competition.

2016 ◽  
Vol 96 (1) ◽  
pp. 151-159 ◽  
Author(s):  
Gan Yantai ◽  
K. Neil Harker ◽  
H. Randy Kutcher ◽  
Robert H. Gulden ◽  
Byron Irvine ◽  
...  

Optimal plant density is required to improve plant phenological traits and maximize seed yield in field crops. In this study, we determined the effect of plant density on duration of flowering, post-flowering phase, and seed yield of canola in diverse environments. The field study was conducted at 16 site-years across the major canola growing area of western Canada from 2010 to 2012. The cultivar InVigor® 5440, a glufosinate-resistant hybrid, was grown at five plant densities (20, 40, 60, 80, and 100 plants m−2) in a randomized complete block design with four replicates. Canola seed yield had a linear relationship with plant density at 8 of the 16 site-years, a quadratic relationship at 4 site-years, and there was no correlation between the two variables in the remaining 4 site-years. At site-years with low to medium productivity, canola seed yield increased by 10.2 to 14.7 kg ha−1 for every additional plant per square metre. Averaged across the 16 diverse environments, canola plants spent an average of 22% of their life cycle flowering and another 27% of the time filling seed post-flowering. Canola seed yield had a negative association with duration of flowering and a positive association with the days post-flowering but was not associated with number of days to maturity. The post-flowering period was 12.7, 14.7, and 12.6 d (or 55, 68, and 58%) longer in high-yield experiments than in low-yield experiments in 2010, 2011, and 2012, respectively. We conclude that optimization of plant density for canola seed yield varies with environment and that a longer post-flowering period is critical for increasing canola yield in western Canada.


Nativa ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 284
Author(s):  
Ana Laura Pereira Souza ◽  
Marcelo Marques Costa ◽  
Darly Geraldo de Sena Junior ◽  
Rogério Borges de Oliveria Paz

O Índice de área foliar (IAF) representa a eficiência na interceptação e utilização da radiação solar pelas plantas. O IAF pode ser obtido de forma direta, determinando-se a área foliar e área ocupada pela planta. Entretanto, métodos indiretos são comumente utilizados para sua estimativa devido a necessidade de praticidade. O objetivo deste trabalho foi avaliar a equivalência das estimativas do IAF obtidas por meio de um ceptômetro, pelo método de discos e utilizando imagens digitais. Para tanto, foi conduzido um experimento com a cultura da soja, no delineamento em blocos casualizados, com variação da densidade de plantas, para comparar os valores de IAF obtidos pelos diferentes métodos aos 34 dias após a semeadura (DAS). A comparação foi feita por meio dos coeficientes de equações lineares ajustadas entre os resultados obtidos. O método do disco e do ceptômetro, apresentaram uma boa equivalência entre seus valores. Entretanto, o método que utiliza imagens superestimou o IAF, não apresentando uma boa equivalência de seus valores aos do método de discos e ao ceptômetro.Palavras-chave: ceptômetro, discos foliares, imagens digitais. EVALUATION OF THREE OBTAINMENT METHODS OF FOLIAR AREA INDEX FOR SOYBEAN CROP ABSTRACT:The leaf area index (LAI) represents the interception efficiency and use of solar radiation by plants. IAF can be obtained directly, determining the leaf area and area occupied by the plant. However, indirect methods are commonly used for their estimation because for practicality. The objective of this work was to evaluate the equivalence of the LAI estimates obtained with a ceptometer, using the disc method and digital images. A experiment was conducted with soybean crop, in a randomized block design with plant density variation to compare the LAI values obtained by the different methods at 34 days after sowing (DAS). The comparison was made through the coefficients of linear equations adjusted between the results obtained. The disc and the ceptometer method presented a good equivalence between their values. However, the imaging method overestimated the LAI, not presenting a good equivalence of its values to those of the disc method and the ceptometer.Keywords: ceptometer, leaf discs, digital images.


2019 ◽  
pp. 54-78
Author(s):  
Yaroslav Tsytsiura

The article presents the results of a long-term study of the features of the phytocenology of agrophytocenoses of oil radish using different methods for assessing their condition and studying the tactics of the plant vitality strategy. A comprehensive assessment was made of the effect of changes in row spacing, seeding rates and fertilizer rates on the formation of various plant morphotypes, the variability of morphological characters and the general characteristics of plant viability. Three idiotypes of the plant oil radish were identified in a vertical study of agrophytocenosis, on the basis of which a detailed analysis of the variability of each group and a statistical assessment of the reliability of its existence were carried out. The features of the morphological integration of each tier are analyzed and its impact on the formation of the overall field productivity is evaluated. Based on the modular and vitality grouping, the effectiveness and feasibility of combining various options for plant density and fertilizer in the range of 30-90 kg of active substance per 1 ha were evaluated. Conclusions are drawn about the desired model of agrophytocenosis of oil radish based on the characteristics of its vital tactics and the goals of its growing. Grouping was carried out according to a variety of morphological traits of plants in the population and the possibilities of applying the basic patterns of phytocenology in their application to radish oilseed plants were evaluated. Through the use of regression analysis, the influence of climatic conditions on the formation of various morphological types of plants and the nature of the relationship of plants of oil radish in cenoses of various densities against the background of various fertilizer options has been evaluated. The main promising areas for further research on the peculiarities of creating highly productive and highly adaptable agrophytocenoses of oil radish have been outlined.


2013 ◽  
Vol 58 (3) ◽  
pp. 209-215
Author(s):  
Mahdi Faravani ◽  
Behjat Salari ◽  
Mostafa Heidari ◽  
Mohammad Kashki ◽  
Barat Gholami

In order to understand the effect of organic fertilizer on yield of anise, an experiment was conducted in the form of split-plot in randomized complete block design with three replications in Mashhad, Khorasan Agriculture and Natural Resource Research Center. Four treatments of fertilization: the control, vermicompost - 5 t/ha, cow manure - 25 t/ha, and mineral fertilizer (NPK) - 60 kg/ha (the same rate of each nutrient) were applied as the main factor. The second factor was plant density, applied at three levels: 17, 25, and 50 plants/m2. The results showed a significant effect of fertilizer on the number of umbels per plant, number of umbellets per umbel and canopy cover. Plant density had a significant effect on grain yield, biological yield, the number of lateral branches, essential oil percentage and yield of essential oil. Seed and essential oil yield were the highest in the case of the application of vermicompost and plant densities of 50 and 25 plants/m2 respectively.


Author(s):  
Murphy Kayode M ◽  
Ozigbo Emmanuel S ◽  
Adunoye Francis O

The performance of plantain fruit yield and quality under different planting densities under an influence of irrigation system was investigated at International Institute of Tropical Agriculture, Ibadan, Oyo State, Nigeria. Experiments were set up as a split plot fitted into randomized complete block design (RCBD) with three replications. Main plots are irrigation system while sub-plots are plant densities. Treatments included four plant densities (1 x 2, 2 x 2, 2 x 3, and 3 x 3 m), two irrigation systems and their combination where irrigation system was the main plot and plant density the sub-plot. Over 2,000 agbagba suckers were pared and hot–water treated, and planted during the first week of the experiment. Manure was applied at the rate of three spades full per plant for nutrient supplement; and mulching was done. Weeds were manually controlled as at when due. Plantain diseases like yellow sigatoka and black sigatoka were also controlled manually by de-leafing infected leaves to prevent disease spread. Data were collected and analyzed using ANOVA. Duncan multiple range test (DMRT) was used for mean separation at 5% level of significance. The results of ANOVA showed that there were significant effects (P < 0.05) due to irrigation application for all measured parameters whereas effects due to plant densities were significant for only these parameters; number of suckers (NOS), sucker height (SUHT), number of leaves on sucker (NLSC), bunch weight (BWT), number of hand (NHND), total number of finger (TFNG) and number of sucker at flowering (NSCK). Therefore, it can be concluded that plant spacing, and regular water supply plays a significant role in obtaining good yield in plantain production


Moringa is a typical representative of multi-purpose tropical tree crop due to the high nutritional value, it is an important source for food to many communities and provides raw materials for animal feed industries. This study investigates the influence of plant densities (15 x 15 cm, 15 x 20 cm, 20 x 20 cm, and 20 x 30 cm) and four (4) harvesting intervals (HI) of 2, 4, 6 and 8 weeks was laid out using Randomized Complete Block Design (RCBD) replicated three times. Data on silvicultural practices were collected and six (6) plants were randomly selected for harvest from each plot which were subsequently separated into leaves, stems and twigs. Fresh and air-dried weights were recorded for analysis. Analysis of Variance (ANOVA) was used for data analysis Duncan’s Multiple Range Test was used to separate the means. Results of the present study show non-significant effects of plant density (p>0.05) between treatments. However, greater number of branches, leaves, height and biomass accumulation was recorded at 8 weeks harvesting interval. A significant interaction effects were recorded between spacing and HI.


Author(s):  
Murray D. Hartman ◽  
Scott R. Jeffrey

Canola production in western Canada has expanded such that in many regions canola area rivals the area seeded to wheat. This change can be mainly attributed to adoption of herbicide resistant hybrid varieties, and resulting higher relative profitability. Producers responded to higher seed prices by reducing seeding rates, leading to plant densities that were often lower than industry recommendations. The study objectives were to examine canola yield response to plant density and assess economically optimal density levels relative to industry recommendations and grower practices. A meta-analysis approach was applied to yield response and plant density data with herbicide resistant hybrid canola from multiple studies. Three alternative marginal yield-density functions were estimated and used to calculate economically optimal plant density. Sensitivity of results to key parameters was assessed. Resulting optimal density levels under recent average prices, seed size and emergence were 62-73 plants m-2, consistent with industry recommendations for western Canada. Recent field surveys report lower densities than this range, suggesting that producers are seeding at less than optimal rates. However, there is significant uncertainty associated with canola production, and interaction of seeding rate with other factors. These would impact on optimal plant density, although much of the uncertainty remains until well after seeding. The empirical results represent a foundation for development of more detailed models, highlight the significance of the relationship between plant density and economically optimal yield, and suggest the need to develop decision making tools to support producers in making canola planting decisions.


2021 ◽  
Vol 30 (1) ◽  
Author(s):  
Tuan Minh Tran ◽  
Quang Huy Nguyen

In recent years, experimental and numerical researches on the effect of blasting pressure on the stability of existing tunnels was widely obtained. However, the effect of the blasting pressure during excavation a new tunnel or expansion old tunnels on an existing tunnel has disadvantages and still unclear. Some researches were carried out to study the relationship of the observed Peak Particle Velocity (PPV) on the lining areas along the existing tunnel direction, due to either the lack of in situ test data or the difficulty in conducting field tests, particularly for tunnels that are usually old and vulnerable after several decades of service. This paper introduces using numerical methods with the field data investigations on the effect of the blasting in a new tunnel on the surrounding rock mass and on the existing tunnel. The research results show that not only predicting the tunnel lining damage zone under the impact of blast loads but also determination peak maximum of explosion at the same time at the surface of tunnel working.


2020 ◽  
pp. 1202-1208
Author(s):  
Luan de Oliveira Nascimento ◽  
Josimar Batista Ferreira ◽  
Gleisson de Oliveira Nascimento ◽  
Vanderley Borges dos Santos ◽  
Clemeson Silva de Souza ◽  
...  

Increasing corn grain production without devastating new forest areas is a viable alternative to controlling deforestation. However, increasing plant density in the area may alter plant morphophysiological and productive traits. The objective of this study was to characterize relationships between physiological, morphological and yield traits of corn plants, as well as the cause, effect and relationship of the traits on grain yield. The experiment was carried out in randomized complete block design with four replications. The corn hybrids (2B655PW, AG7088PRO3 and P4285YHR) were grown with row spacing of 40 cm, 60 cm, 80 cm, 95 cm. The evaluated traits physiological were: net photosynthesis (PN), stomatal conductance (Gs), intercellular concentration of CO2 (Ci), leaf transpiration (E), water use efficiency (WUE) and carboxylation efficiency (CE). The morphological were: plant height (PH) and ear insertion height (EIH), stem diameter (SD), and leaf area (LA) and the productive traits were the total number of ear per hectare (NE), number of grains per ear (NGE), grain mass per ear (GME), 100 grain weight (100GW) and grain yield (GY). The characteristics of maize hybrids cultivated in environment with reduced spacing (40cm, 60cm, 80cm, 95cm) of the 2016/2017 crop were investigated through the multicollinearity path analysis. The physiological, morphological and productive traits are considered sources of variation of cause and effect of corn yield in reduced spaced. This traits are essential for observations in maize breeding programs to obtain high yielding varieties in reduced spacing. In conclusion, the physiological (PN, CE, WUE, Ci, Gs), morphological (EIH, SD, LA) and productive (NE, GME) traits provide gains in maize grain yield via indirect selection when the crop is subjected to 40 cm row spacing.


Revista CERES ◽  
2014 ◽  
Vol 61 (3) ◽  
pp. 424-433 ◽  
Author(s):  
Maria do Carmo Lana ◽  
Leandro Rampim ◽  
Tatiane Ohland ◽  
Fernando Fávero

The objective of this study was to evaluate yield components, leaf nitrogen content and grain yield in corn as affected by row spacing, plant density and nitrogen topdressing. The experiment was conducted with the single-cross hybrid AG 8021, in the municipality of Toledo-PR, in an Oxisoil under no-tillage system, in the crop year 2005/ 2006. The experiment was arranged in a randomized block design and treatments in split-split-plots, with four replications. The two row spacings (0.45 and 0.90 m) were allocated in the main plots, the two plant densities (60,000 and 80,000 plants ha-1) were allocated in the subplots and the three nitrogen rates (80, 100, 120 and 140 kg ha-1 N) were allocated in the sub-subplots. Topdress nitrogen was applied using urea as N source. The rise of the plant population from 60,000 to 80,000 plants ha-1 and the application of topdress nitrogen resulted in increased production components. The application of topdress fertilization provided increase in leaf N content and grain yield for the spacings 0.45 m and 0.90 m. Yield was higher in the spacing 0.45 m than 0.90 m. Yield was higher with 60,000 plants than with 80,000 plants at 0.90 m, while at 0.45 m there was no difference in relation to the plant density.


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