Ear Insertion Height Research Articles

Agronomic performance of mayze hybrids under application of prohexadione-calcium and nitrogen topdressing

The use of prohexadione-calcium (ProCa) is a management alternative to mitigate greater predisposition to vegetative growth. The objective of this study was to evaluate the use of ProCa in combination with two doses of nitrogen fertilizer in cover, in the morphophysiological and productive performance of corn hybrids. Experiments were performed with corn hybrids AS1757VTPRO3 and AG9025VTPRO3, in a randomized block design, factorial 2×2, with four replications. The treatments consisted of the application of nitrogen fertilizer in cover, 1x and 2x the recommended dose, and in the absence or presence of the application of ProCa. The single effect of ProCa on the hybrid AS1757VTPRO3 increased the SPAD index by 20%; in the AG9025VTPRO3 hybrid there was a reduction of 8.6 cm in the height of ear insertion and increments of 2.2 mm in the stem diameter. The application of ProCa with 2x N ha-1 increased, on average, 8.2% the number of leaves of the AS1757VTPRO3 hybrid compared to the application to 1x N ha-1. There is single effect of ProCa on morphophysiological characteristics in the tested hybrids, but without affecting its grain yield. The use of ProCa in association with 2x N ha-1 does not mitigate the vegetative growth in the genotypes, sown late in the South of Brazil.

Does foliar nicotinamide application affect second crop corn (Zea mays)?

The largest corn yeld in Brazil is currently in the second harvest, which is the most susceptible period to climatic adversities occurring during the cycle. Thus, introducing beneficial elements for maintaining the adequate development of the plant can help producers in obtaining greater kernel yields. Among studied elements, nicotinamide has potential use since it is associated with accumulating secondary metabolites and manifesting defence metabolism in plants. The objective of this work was to evaluate the influence of nicotinamide applied in different doses (only once or in instalments) on the biometric and productive characteristics of corn. The treatments were composed by the number of nicotinamide applications (one or two) and five doses (0, 50, 100, 150 and 200 mg L-1). Plant diameter, plant height, ear insertion height, leaf area and dry matter, yield and 100-kernel mass were evaluated. It was found that doses close to 100 mg L-1 resulted in increases in vegetative and reproductive development, regardless of the number of applications. In this way, foliar nicotinamide application positively influences the biometric and productive characteristics of second crop corn. Highlights The use of nicotinamide in corn plants improves its growth, yield components and grain yield. A single application of nicotinamide during vegetative stage V3 at a dose of 100 mg L-1 is sufficient to increase the leaf area of corn plants. Corn grain yield can be increased by 12.6% with a single application of nicotinamide. There was no need for two applications of nicotinamide in corn crop.

Evaluation of corn hybrids for silage grown in different locations

ABSTRACT The aim of this study was to evaluate the yield, morphometric and chemical characteristics, and the digestibility of various corn hybrids cultivated in different locations for silage production. Four corn hybrids were grown: P2866H, P3456H, P30R50VYH and P4285YHR, in four locations, defined as farm A; B; C and D. The hybrid P4285YHR presented the highest plant and ear insertion heights (2.72m, 1.52m respectively), with a minimum registered height of 2.63 m and 1.42 m, for plant and ear insertion height, and for that reason it presented the highest yield of fresh biomass (78,089kg ha-1). The TND values showed trend very close to that observed in the DISMS of the whole-plant, with hybrid P3456H presenting the highest estimated value (68.74%), and the hybrid P4285YHR the lowest among them (65.25%). In general, lower fibrous carbohydrates and lignin content, higher fibrous carbohydrates content, together with satisfactory grains participation in the plant structure led to a greater dry matter digestibility. Hybrids with lower plant heights do not necessarily have lower dry biomass yields, but hybrids of greater height and with high stem and leaf participation tend to have a higher aFDN content and less dry matter digestibility.

Times of Trinexapac-ethyl application associated to plant densities in agronomic performance of second-season corn

Plant growth regulators, which can alter the plant size and anatomy, allow the use of cultivars of interest that do not have a modern leaf architecture, making higher plant densities possible. The objective of this study was to evaluate the agronomic performance of second season corn, grown at different plant densities and under Trinexapac-ethyl applications at different stages of crop development. The field study was carried out in two growing seasons (2013 and 2014), at the Fazenda Escola of the State University of Londrina. Fifteen treatments were evaluated in a randomized block, 5 x 3 factorial design, at five plant densities (40,000, 60,000, 80,000, 100,000 and 120,000 plants per hectare), of Trinexapac-ethyl applied in three stages: control (no application), V6 and V9, with four replications. The morphological plant characteristics, the yield components and grain yield were evaluated. Increases in plant density raise the plant height, reduce the number of grains per ear, ear length and 100-kernel weight, and have no influence on grain yield. The application of Trinexapac-ethyl in stage V9 reduces plant and ear insertion height and 100-kernel weight.

The results of the assessment of self-pollinated precocious lines of maize (Zea mays L.) on the main economically valuable traits at two sowing dates

Purpose. Comprehensive study, selection, evaluation and systematization of self-pollinated lines of maize (Zea mays L.) obtained on the basis of material of diffe­rent genetic structure from endosperm of flint and dent maize were implemented according to the main economically valuable traits and precocity in order to select the best genotypes for selection. Methods. Hybridization, inbreeding were used in the process of creating the initial material; visual method – for phenological observations; laboratory and field – to determine the morphobiological characteristics of self-pollinated lines of maize; measuring and weighing – to account the harvest and determine the metric characteristics of plants; mathematical and statistical – to determine the validity of the results, indicators of trait variability, correlation dependence of traits; analysis of variance; comprehensive assessment of morphobiological and economically valuable traits of self-pollinated maize lines of the most common germplasms. Results. As a result of assessment of self-pollinated lines of the most common germplasms, it was revealed that the highest level of grain yield was obtained under both sowing periods – Iodent germplasm; the minimum grain moisture content – Flint and Mix germplasms; the shortest average duration of the emergence – flowering of 50% of male and female inflorescences stage – Flint germplasm; steadily high va­lues ​​of plant height for germplasm Mix – under the optimal sowing date, and Iodent plasma – under the late sowing date. Steadily high values ​​of the ear insertion height at both sowing dates were obtained for lines based on Iodent germplasm. The number of the most precocious and the best by the economically valuable traits germplasms of self-pollinated lines were identified. Conclusions. The DK239 lines – Flint germplasm, DK7174, DK2285, DK305, DK2613, DK5568 – Iodent germplasm, DK2332 and DK2659 – Mix germplasm were the most precocious and the best by the economically valuable traits. They are promising for the selection of ultra-early hybrids of maize adapted to the conditions of the Steppe of Ukraine.

Plant density and nitrogen topdressing of high-altitude main-season corn

An appropriate combination of plant density with nitrogen (N) fertilization can optimize corn growth and increase grain yields. This study evaluated the effects of nitrogen topdressing rates and plant density levels on the agronomic performance of corn. The early hybrid DKB 240 YG, with high yield potential and stability, was evaluated in two summer crops in Mauá da Serra, Paraná (950 m asl), in a Cfb climate, on a Rhodic Eutrudox. The experiment was arranged in randomized complete blocks and subdivided plots with four replications. The plant densities (60,000; 75,000; 90,000 and 105,000 plants ha-1) were assessed in the plots and the nitrogen (ammonium nitrate 32% N) topdressing rates (0, 60, 120, 180 and 240 kg ha-1) in the subplots. The stem diameter, plant height, ear insertion height and grain yield were evaluated. The stem diameter, plant height, ear insertion height and grain yield were influenced by the interaction between plant density and nitrogen topdressing under the tested high-altitude edaphoclimatic conditions. The stem diameter of corn plants decreased due to the increase in plant density whereas nitrogen topdressing attenuated this reduction. Maximum plant height was observed at a density of 75,000 plants ha-1 associated with a topdressing of 169 kg ha-1 of N, and highest ear insertion at 60,000 plants ha-1 and 168 kg ha-1 of N. Corn yield was highest at a density of 105,000 plants ha-1 associated with a topdressing of 185 kg N ha-1 of N.

UAV-based multispectral sensor to measure variations in corn as a function of nitrogen topdressing

Carrying out monitoring during the crop cycle through vegetation indices (VIs) with obtained unmanned aerial vehicle allows agility in decisions about management practices, as well as concerning nutritional deficiencies in crops, as nitrogen (N). This nutrient absorbed in greater quantity, and that most influences the grain yield in corn. This research hypothesized that different N topdressing levels can affect the agronomic performance of corn varieties and that those effects can be expressed by VIs. The objective was to evaluate the use of VIs in the monitoring of corn varieties submitted to different N levels. Two experiments were carried out in a randomized block design with three replicates in a factorial scheme, replicated for two crop seasons (2017/2018 and 2018/2019). The first factor was composed of 11 cultivars of corn. The second factor was composed of two contrasting N levels (60 kg ha−1 - low and 180 kg ha−1 - high). Vegetation indices (NDVI and NDRE) and agronomic traits (leaf N content, plant height, ear insertion height, stem diameter, ear length, number of rows per ear, number of grains per row, and grain yield) were evaluated. Our findings allow us to understand how top dressing can influence the agronomic performance of corn genotypes and their relationship with UAV-vegetation indices in two crop seasons using Sensefly Sequoia multispectral sensor. High N topdressing levels provides better agronomic and spectral response in corn, regardless of the variety used. This behavior can be confirmed through the NDVI and NDRE. High N topdressing levels provides a positive correlation between the VIs evaluated (NDVI and NDRE) with the grain yield in corn.

Resposta da produtividade do milho à adubação mineral e organomineral

Há um aumento das importações de fertilizantes minerais para suprir as necessidades do mercado interno. Sendo assim os fertilizantes organominerais surge como uma alternativa para fornecimento de nutrientes as plantas e a diminuição da dependência em relação as importações dos fertilizantes minerais. O experimento foi estruturado em delineamento em blocos casualizados com cinco tratamentos e quatro repetições, o arranjo dos tratamentos foi realizado a partir da combinação da aplicação do adubo mineral e organomineral em plantio e cobertura. Aos 30, 60 e 90 (fase de grão pastoso) DAE foram obtidas as variáveis em análise, como diâmetro de colmo (DC), altura de planta (AP) e altura de inserção da espiga (AIE). Para estimar a massa verde (MV) e seca (MS) das plantas foram recolhidas as partes aéreas durante o florescimento pleno da cultura. Foram poucas mudanças observadas no desenvolvimento das plantas como resultado do uso do organomineral em plantio ou cobertura, sendo que somente aos 30 DAE pode-se observar diferenças estatísticas entre os diferentes tratamentos nas variáveis altura e diâmetro das plantas. O milho apresentou maior produtividade com o uso de adubo organomineral em plantio e cobertura.

Corn response to phosphogypsum, base saturation and lime application method

The lime (L) and phosphogypsum (G) promote changes in the chemical attributes of the soil that can alter the development of corn. The objective was to evaluate morphological and yield components of corn after liming and G and to correlate them with yield. The treatments consisted of a 2 x 4 + 3 factorial, with two methods of application of L: surface (SL) and incorporated (IL) to obtain different levels of base saturation (BS): 44, 60, 70 and 90%. Three additional treatments were evaluated involving the use of L and G applied on the surface, being: BS 60% + 3.71 Mg ha-1 of G (60G50); BS 70% + 3.71 Mg ha-1 of G (70G50) and BS 70% + 7.42 Mg ha-1 of G (70G100). Plant height (PH), ear insertion height (EIH) and stem diameter (SD) were not influenced by the treatments. The SL increased the length of the ear (LE), number of grains per row (NGR) and mass of a thousand grains (TMG) up to BS of 72, 80 and 72%, respectively. Thus, there were no advantages of higher base saturation (BS 90%). The combination of L and G promoted improvements in ear diameter (ED), NGF, LE, TMG. The yield in IL was 445 kg ha-1 higher than SL, however when combining G and L the production increased 6 to 12% in relation to BS 44% SL. BS% levels in IL did not influence any response variable. Grain yield was positively correlated to ED, TMG, LE and PH.

Analysis of growth and agronomic characteristics of off-season corn grown insuccession with soybean and submitted to nitrogen doses

Nitrogen (N) fertilizer management strategies for the cultivation of off-season corn grown in succession to soybean can be established by growth analysis. Therefore, the objective was to evaluate the growth and agronomic performance of corn in the off-season due to nitrogen levels in an Oxisol of the Cerrado of the state of Mato Grosso do Sul, Brazil. The experimental design used was in randomized blocks, arranged in a split-plot scheme, with six replications. The plots were formed by five nitrogen doses (0, 40, 80, 120 and 160 kg ha-1 of N), and the time of evaluation of the corn development parameters (30, 45, 60 and 75 days after emergency (DAE)) constituted the subplots. The source of N used was urea (45% N), with 30 DAE applied. The cultivar Invictus Viptera 3 of corn was cultivated in the off-season. Plant height, leaf area, number of leaves, dry mass of the plant shoot, physiological indexes of growth analysis were evaluated at 30, 40, 60 and 75 DAE. In the flowering period of corn, after the emission of the female inflorescence, were determined the indirect readings of the leaf chlorophyll, leaf N, height plant, and height of the ear insertion. At the physiological maturity of the grain was evaluated height of ear insertion, ear length, number of rows per ear, number of grains per row and ear diameter, the mass of a thousand grains, and grain yield. The 160 kg ha-1 dose of N showed better performance and higher morphophysiological indices for corn off-season in succession to the soybean crop. However, the higher grain yield of corn was obtained with the 126 kg ha-1 of N.

Relationship between the agronomic and anatomical characteristics of the leaf with a view to indirect selection in maize plants

ABSTRACT In crops such as maize, the leaf is directly related to dry-matter accumulation in the grain, and directly affects plant yield. The aim of this study was to verify the existence of a correlation between the agronomic and anatomical characteristics of the maize leaf, as well as to verify the effects of these characteristics on grain production using path analysis. The agronomic characteristics used in the analysis were plant height, height of ear insertion, relative position of the ear, lodging, plant breakage and grain yield. The following anatomical characteristics were evaluated: total leaf area, thickness of the bulliform cells, thickness of the adaxial and abaxial epidermis, thickness of the mesophyll, area of the xylem, phloem and sclerenchyma, and mean area of ​​the vascular bundles. In analysing the genotypic correlation, associations were seen at 1% significance between mesophyll thickness and plant height, mesophyll thickness and height of ear insertion, and mesophyll thickness and plant breakage, indicating the possibility of indirect selection for these agronomic characteristics. From the path analysis, it was found that the agronomic characteristics of lodging and breakage, and the anatomical characteristics of thickness of the adaxial epidermis, area of ​​the xylem and area of ​​the sclerenchyma had the greatest direct effect on grain yield, indicating the additional possibility of indirect selection for yield during the earliest stages of the plant. These results can afford faster selection of superior genotypes within the various breeding programs of the species.

Performance of maize hybrids as a function of spatial arrangements during second growth season under irrigation

ABSTRACT There is little information on how different spatial arrangements affect modern maize hybrids under irrigation in the maize second growing season in Brazil. The objectives of this study were to evaluate the performance of maize genotypes with different canopy architecture as a function of different spatial arrangements in the Southeast Brazil. Two maize hybrids with semi-erect (DKB 390) and erect (DKB 230) leaves were cultivated during the second season and evaluated for different plant densities (4, 7 and 10 × 104 plants?ha?1) and row spacings (0.25, 0.50 and 1.00 m), under irrigation in a tropical environment. The increase in plant density increased plant height and ear insertion height, but reduced stalk diameter. The absorbed photosynthetically active radiation and the leaf area index also increased in higher plant densities, with a reduction of the SPAD index. The increase in plant density enhanced grain yield, however, there was no difference of yield between different row spacings. The hybrid DKB 230 (upright leaves) showed greater yield potential compared to DKB 390 (semi-upright leaves). The critical leaf area index was 5.2 and 4.3 for the hybrids DKB 230 and DKB 390, respectively. The estimated plant density that provides the maximum yield are 9.7 × 104 and 8.8 × 104 plants?ha?1 for the hybrids DKB 230 and DKB 390, respectively.

Survey and Collection of Maize Cultivars in Benin and Evaluation of Their Agro-Morphological Characteristics

Seeds are the most important input in agricultural production. Quality seed determines the yield of the crop and contribute to nearly 30% of crop productivity. The present study aims at surveying and collecting maize accessions in the township of North, Centre and South Benin and for their agro-morphological characterization. To this end, 32 accessions were collected from 11 townships of Benin. The villages for maize collection were chosen with the help of the heads of the association of producers in each township. The cultivars collected were put in different envelopes properly labelled. In order to evaluate the agro-morphological characteristics of the cultivars, four experiments were set up in Bassila, Glazoue, N'Dali and Adjohoun. Eighteen (18) quantitative parameters were measured at each site. The statistical analyses for the different quantitative characters showed that there was a great diversity between cultivars. The significant differences (p< 0.001) between cultivars for the different quantitative traits confirmed the diversity that existed between these cultivars. The observed diversity among cultivars were due to plant height, developmental life cycle, ear and yield parameters. These descriptors are therefore the most important to explain the variability among cultivars. Positive correlations were observed among traits. Thus, the cultivars of great high had large crown, long panicle branching, higher ear insertion height, long leaves and an average number of leaves above the ear. Cultivars with long panicles showed large and long spikes, higher panicle branching and a high number of primary panicle branches

Principal component analysis for selection of superior maize genotypes

Constant advances in studies on the behavior of maize genotypes and their interactions with the environment are of great importance for the best performance of the plant. This study verifies effects and causes of agronomic variables of maize hybrids on grain yields and performs the indirect selection of superior genotypes by principal component analysis (PCA). Two hundred and thirty maize genotypes were used, with two hundred and twenty- -nine topcross hybrids (consisting of crossings of two hundred and twenty-nine partially inbred genotypes with a tester) and one check in a randomized block design with two repetitions. The genotypes were evaluated during the 2016 and 2016/2017 crops considering the agronomic variables plant height, ear insertion height, ear position, lodging, breakage, and grain yield. Data were submitted to analysis of variance and means were compared by the Scott-Knott test (p<0.05) with subsequent multivariate exploratory analysis by PCA. In the principal component analysis, components explained 52.07% and 55.69% of the variance contained in the original variables for the 2016 and 2016/2017 crops, respectively. The variable that was most significant in both crops was ear insertion height, allowing the indirect selection of more productive genotypes. Indirect selection of the most productive genotypes was also conducted through variables that contributed significantly in the principal component analysis. Thus, the use of multivariate exploratory analysis is efficient in the characterization and selection of maize genotypes evaluated in different crop seasons.

WEED CONTROL IN “LL” MAIZE TOLERANT TO GLUFOSINATE-AMMONIUM

The glufosinate-ammonium is an herbicide with contact action and, whenused in tolerant LL maize, requires associations with other products to improve the weed control spectrum and increase the residual period in the area. The aim of this work was to evaluate the efficacy and selectivity of glufosinate-ammonium, applied alone and in combination with other herbicides, for weed control in maize crops. The treatments consisted of two strategies. In the first one, the following herbicides were applied in pre-emergence conditions: atrazine, [atrazine + simazine], [atrazine + oil], [atrazine + S-metolachlor], and S-metolachlor; with the subsequent application of glufosinate-ammonium in post-emergence condition of maize. The second application method corresponded to the use of glufosinate-ammonium, alone and combined with nicosulfuron + mesotrione and the other products used in the first strategy, in addition to two control areas, being one weed-infested and the other weed-free. Phytotoxicity on maize and weed control were assessed. Ear insertion height, number of rows per ear, number of grains per row, thousand grain weight and maize yield were determined upon harvesting. The herbicides were effective and did not cause yield loss to the crop. The herbicides applied in combination with glufosinate-ammonium were efficient in regard to weed control and selective to maize.

AGRONOMIC PERFORMANCE OF SUMMER MAIZE IN CROP ROTATION SYSTEMS

Maize grown in the summer can be an important option for crop rotation with soybean. The objective of this work was to study the agronomic performance of maize in different crop rotation systems. The experiment was conducted at the Experimental Farm belonging to the College of Agricultural Sciences of the Federal University of Grande Dourados (UFGD), located in the municipality of Dourados, MS, in the agricultural year of 2014/15. Randomized block design was used, with ten treatments and four replications. The treatments consisted of precedent crops: white oat (Avena sativa), forage radish (Raphanus sativus L. var. oleifera), showy rattlebox (Crotalaria spectabilis), fodder vetch (Vicia villosa), crambe (Crambe abyssinica), safflower (Carthamus tinctorius L.), niger (Guizothia abyssinica), canola (Brassica napus L. var. oleifera), wheat (Triticum aestivum L.) and fallow. These crops were planted in the fall/winter season of each agricultural year, while maize was sown in October of each year. Plant height, ear insertion height, ear length and diameter, grains per ear, thousand grain weight and yield were evaluated. There was significant difference only for yield, which presented the highest values in the rotation with safflower, canola, forage radish, wheat, white oat and niger.

APPLICATION OF DIFFERENT SOURCES AND DOSES OF BORON IN THE CORN CROP

One of the main problems faced in corn cultivation, especially in Cerrado regions, is the deficiency of micronutrients. Among the micronutrients essential for the development of plants, boron (B) stands out for participating in a series of physiological processes. Based on this, the present work aimed to evaluate the performance of corn under fertilization with different sources and doses of boron. The randomized block design in a 4x3 factorial scheme was used. Four boron doses (0, 1, 2, and 3 kg ha-1) and three nutrient sources (boric acid, borax, and ulexite), applied in topdressing, were evaluated. Plant height (cm), stem diameter (mm), first ear insertion height (m), ear length (cm), ear diameter (mm), number of rows per ear, number of grains per row, 1000-grain weight (g), and grain yield (kg ha-1) were evaluated. It was concluded that the boron sources and doses used did not influence the results of plant height, first ear insertion height, number of rows per ear, and grain yield. The three doses evaluated provided increases in stem diameter, with a dose of 2.08 kg ha-1 being the one with the highest average. The application of borax and ulexite results in higher values of ear diameter, number of grains per row, and 1000-grain weight. The dose of 1.74 kg ha-1 of boron provides the highest 1000-grain weight.

Ozonized Water in the Preconditioning of Corn Seeds: Physiological Quality and Field Performance

ABSTRACT Corn is a cereal of great economic and social importance worldwide. The objective of the present work was to evaluate the effects on the physiological quality and the performance in the field of corn seeds with different quality standards before and after hydropriming with ozone. To evaluate the effects on the physiological quality, two batches (one with high physiological quality and the other with low physiological quality) of corn seeds were used. Seeds from both batches were immersed in distilled water and bubbled with atmospheric air (control - 0 mg L-1) or ozone. Three inlet concentrations of ozone (0, 10, and 20 mg L−1) and five periods of preconditioning (0, 30, 60, 90, and 120 min) were used. To evaluate the physiological quality of the seeds, different tests were carried out both in the laboratory and in the field. The use of the corn seed hydropriming with atmospheric air or ozone favored the physiological quality of the corn seeds when considering laboratory and field variables. There was an increase of emergence in the field of seeds not submitted to aging (high physiological quality) only due to the preconditioning period. The use of ozone was positive in lowering the loss of cellular solutes in seeds submitted to aging. Ozonation also caused significant increases in the plant heights and in the first ear insertion height. The binomial 20 mg L−1/60 min is the most suitable for preconditioning corn seeds in ozonated water.

Spatial arrangement of maize plants aiming to maximize grain yield in the hybrid BRS-3046

The objectives of this study were to: (i) evaluate the effect of different spatial arrangements on morpho-physiological characteristics and (ii) determine the optimal spatial arrangement to maximize grain yield of the maize hybrid BRS-3046 grown in the Mid-North region of Brazil. We tested two row spacings (0.5 and 1 m) and five plant densities (2, 4, 6, 8, 10 plants m-2), which corresponded to 10 different plant spatial arrangements. Different morphophysiological variables, gas exchange rates and grain yield were measured. The increased planting density led to a linear increase in LAI, regardless of row spacing, while the net CO2 assimilation rate increased until the density of 4 and 6 plants m-2, under a row spacing of 0.5 and 1.0 m, respectively. On the other hand, we found a linear reduction in the stomatal conductance with increasing planting density. The intercellular CO2 concentration and the transpiration rate were higher in the widest row spacing. The instantaneous efficiency of carboxylation, in turn, showed a slight increase up to the density of six plants m-2, then falling, regardless of row spacing. Increasing plant density resulted in a linear increase in plant height and ear insertion height, regardless of row spacing. However, it had an opposite effect on stem diameter. Grain yield, in turn, increased up to 7.3 plants m-2 at a row spacing of 0.5 m and 8 plants m-2 at a row spacing of 1.0 m. This spatial arrangement was considered as ideal for achieving maximum yield

Effect of reduced spacing on relationship of physiological, morphological and productive traits of corn yield

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.