Light Interception, Photosynthetic Performance, and Yield of Oil Palm Interspecific OxG Hybrid (Elaeis oleifera (Kunth) Cortés x Elaeis guineensis Jacq.) under Three Planting Densities.

Environmental conditions are crucial for crops' growth, development, and productivity. One of the most important physiological factors associated with the production of crops is the use of solar radiation for the photosynthesis process, which determines the amount of assimilates available for crop growth and yield. Three age classes (4, 6, and 14 years) and three planting densities (143, 128, and 115 palms ha-1) were evaluated in a commercial interspecific Elaeis Oleifera x Elaeis guineensis hybrid Coari x La Mé. The light interception patterns and the photosynthetic performance were determined. Measurements were taken of the leaf area, the number of leaves, and incident and photosynthetically transmitted active radiation. Also, photosynthetic rates, light, and yield were measured. The canopy extinction coefficient (Kc) was estimated using the Monsi and Saeki model. Under the evaluated conditions, the average Kc value for 4-year-old palms was 0.44; for the 6-year-old group of palms, the average value was 0.40, and 0.32 for the 14-year-old palms, with coefficients of determination (R2) greater than 0.8. A pattern associated with the age of the crop was observed, where the Kc decreased in groups of adult palms. The results showed increased Kc as the planting density decreased. No statistically significant differences were observed between planting densities or ages in the light and CO2 curves regarding photosynthesis. The leaf level in which the measurement was made influenced photosynthesis. Thus, the highest values of the photosynthesis parameters were observed in leaf 17. The crop yield tended to stabilize 8 years after planting under 143 and 128 palms per hectare, but 14 years after planting, the Fresh fruit bunch (FFB) production was still growing under 115 palms per hectare. The results showed that, up to year 14 after planting, the highest cumulative yield was achieved with 115 palms per hectare. This was partly caused by a sharp decline in production observed under 128 palms per hectare, which could indicate that in the long production cycle of the OxG hybrids, the 115-palms-per-hectare planting density would result in higher cumulative FFB production. Furthermore, the results showed that the optimum planting density for the hybrids of the present study would be 120 palms ha-1, corresponding to a planting distance of 9.8 m between plants.

Influence of C=O groups on the optical extinction coefficient of graphene exfoliated in liquid phase.

Liquid phase exfoliation of graphite is currently one of the most promising graphene production methods at large scale. For this reason, an accurate calculation of the concentration in graphene dispersions is important for standardization and commercialization. Here, graphene dispersions, at high concentrations, were produced by electrochemical exfoliation. Furthermore, a cleaner methodology to obtain graphene oxide by electrochemical exfoliation at high acid concentrations was implemented. The absorption coefficient for graphene and graphene oxide was determined in the optical range (α660 nm= 1414 (±3%) ml mg-1 m-1andα660 nm= 648 (±7%) ml mg-1 m-1, respectively) with an exponential dependence with the wavelength. The difference inαfor both materials is attributed to an increased presence of C=O groups as evidenced by Fourier transform infrared spectroscopy (FTIR), UV-vis and Raman spectroscopy, as well as, in the calculation of the optical extinction coefficient and optical band-gap via Tauc-plots.

Extinction Coefficient Modulation of MoO3 Films Doped with Plasmonic Nanoparticles: From an Effective Medium Theory Description.

This work focused on the application of the effective medium theory to describe the extinction coefficient (Qext) in molybdenum trioxide (MoO3) doped with different kinds of plasmonic nanoparticles, such as silver (Ag), gold (Au), and copper (Cu). Usually, in studies of these materials, it is normal to analyze the transmission or absorption spectra. However, the effect of this type or size of nanoparticles on the spectra is not as remarkable as the effect that is found by analyzing the Qext of MoO3. It was shown that the ß-phase of MoO3 enhanced the intensity response of the Qext when compared to the α-phase of MoO3. With a nanoparticle size of 5 nm, the Ag-doped MoO3 was the configuration that presents the best response in Qext. On the other hand, Cu nanoparticles with a radius of 20 nm embedded in MoO3 was the configuration that presented intensities in Qext similar to the cases of Au and Ag nanoparticles. Therefore, implementing the effective medium theory can serve as a guide for experimental researchers for the application of these materials as an absorbing layer in photovoltaic cells.

Solar radiation effects on growth, anatomy, and physiology of apple trees in a temperate climate of Brazil.

The aim of study was to characterize patterns of interception and distribution of photosynthetically active radiation (PAR) in an apple orchard and to examine its relationship with morphophysiological characteristics of "Royal Gala" and "Fuji Suprema" apple trees. The experiments were conducted during three production cycles in two distinct orchard areas, one covered by black anti-hail netting and another uncovered (control). We analyzed PAR characteristics with data from meteorological sensors installed on the canopy, as well as growth, anatomical, and physiological variables of apple trees. The reduction of PAR by netting influenced the components of radiation balance. PAR intercepted, absorbed, transmitted, and reflected by the canopy under netting decreased by 33%, 31%, 32%, and 46%, respectively, in comparison to uncovered canopy. When leaf area index (LAI) was 1.5 (under netting) and 2.5 (uncovered), maximum PAR interception efficiency was reached. During the three production cycles, a light extinction coefficient of 1.09 and 0.76 was found under netting and in the control, respectively. Plant height was greater under netting in all three cycles for both cultivars. Number of leaves, LAI, and shape index did not differ between treatments. At stage 85, leaves of "Royal Gala" under netting showed lower chlorophyll content and thinner parenchymas in comparison to the control. However, physiological and anatomical characteristics of Fuji "Suprema" did not change under anti-hail netting.

Interception of solar radiation by the productive structures of spring canola hybrids / Interceptação de radiação solar pelas estruturas reprodutivas de híbridos de canola de primavera

The objective of this study was to adjust parameters related to the interception of photosynthetically active radiation (PAR) by reproductive structures of spring canola, with different nitrogen levels and hybrids. Two field experiments were conducted, being one with different sowing dates and hybrids (Hyola 61 and Hyola 432) and another with doses of 10, 20, 40, 80, 160kg ha-1 of N, applied in top dressing. They were conducted in Passo Fundo and Coxilha, RS, Brazil, in 2011 and 2014, respectively.The evaluated variables were: area index of reproductive structures, interception efficiency and extinction coefficient of these structures for PAR. PAR interception increased by increasing the reproductive structures volume. Interception efficiency of PAR by reproductive structures ranged from 45 to 80%. It was higher in the Hyola 61 hybrid and at the highest dose of N. The extinction coefficient of reproductive structures for PAR was 0.44 in non-limiting doses of N.(AU)

O objetivo deste estudo foi parametrizar a interceptação de radiação fotossinteticamente ativa (RFA) pelas estruturas reprodutivas de canola de primavera, em função de doses de nitrogênio e híbridos. Dois experimentos de campo foram conduzidos, sendo um com diferentes híbridos (Hyola 61 e Hyola 432) e outro com doses de N de 10, 20, 40, 80, 160kg ha-1, aplicadas em cobertura. Eles foram conduzidos em Passo Fundo e Coxilha, RS, Brasil, em 2011 e 2014, respectivamente. As variáveis avaliadas foram: índice de área de estruturas reprodutivas, eficiência de interceptação de RFA e coeficiente de extinção dessas estruturas. A interceptação de RFA aumentou com a elevação do volume das estruturas reprodutivas. A eficiência de interceptação de RFA pelas estruturas reprodutivas variou de 45 a 80%, sendo maior no híbrido Hyola 61 e na maior dose de N aplicado. O coeficiente de extinção de estruturas reprodutivas foi de 0,44 em doses não limitantes de N.(AU)

Interception of solar radiation by the productive structures of spring canola hybrids / Interceptação de radiação solar pelas estruturas reprodutivas de híbridos de canola de primavera

ABSTRACT: The objective of this study was to adjust parameters related to the interception of photosynthetically active radiation (PAR) by reproductive structures of spring canola, with different nitrogen levels and hybrids. Two field experiments were conducted, being one with different sowing dates and hybrids (Hyola 61 and Hyola 432) and another with doses of 10, 20, 40, 80, 160kg ha-1 of N, applied in top dressing. They were conducted in Passo Fundo and Coxilha, RS, Brazil, in 2011 and 2014, respectively.The evaluated variables were: area index of reproductive structures, interception efficiency and extinction coefficient of these structures for PAR. PAR interception increased by increasing the reproductive structures volume. Interception efficiency of PAR by reproductive structures ranged from 45 to 80%. It was higher in the Hyola 61 hybrid and at the highest dose of N. The extinction coefficient of reproductive structures for PAR was 0.44 in non-limiting doses of N.

RESUMO: O objetivo deste estudo foi parametrizar a interceptação de radiação fotossinteticamente ativa (RFA) pelas estruturas reprodutivas de canola de primavera, em função de doses de nitrogênio e híbridos. Dois experimentos de campo foram conduzidos, sendo um com diferentes híbridos (Hyola 61 e Hyola 432) e outro com doses de N de 10, 20, 40, 80, 160kg ha-1, aplicadas em cobertura. Eles foram conduzidos em Passo Fundo e Coxilha, RS, Brasil, em 2011 e 2014, respectivamente. As variáveis avaliadas foram: índice de área de estruturas reprodutivas, eficiência de interceptação de RFA e coeficiente de extinção dessas estruturas. A interceptação de RFA aumentou com a elevação do volume das estruturas reprodutivas. A eficiência de interceptação de RFA pelas estruturas reprodutivas variou de 45 a 80%, sendo maior no híbrido Hyola 61 e na maior dose de N aplicado. O coeficiente de extinção de estruturas reprodutivas foi de 0,44 em doses não limitantes de N.

Theoretical approximations and experimental extinction coefficients of biopharmaceuticals.

UV spectrophotometric measurement is a widely accepted and standardized routine analysis for quantitation of highly purified proteins; however, the reliability of the results strictly depends on the accuracy of the employed extinction coefficients. In this work, an experimental estimation of the differential refractive index (dn/dc), based on dry weight measurements, was performed in order to determine accurate extinction coefficients for four biotherapeutic proteins and one synthetic copolymer after separation in a size-exclusion ultra-performance liquid chromatograph coupled to an ultraviolet, multiangle light scattering and refractive index (SE-UPLC-UV-MALS-RI) multidetection system. The results showed small deviations with respect to theoretical values, calculated from the specific amino acid sequences, for all the studied immunoglobulins. Nevertheless, for proteins like etanercept and glatiramer acetate, several considerations, such as glycan content, partial specific volume, polarizability, and higher order structure, should be considered to properly calculate theoretical extinction coefficient values. Herein, these values were assessed with simple approximations. The precision of the experimentally obtained extinction coefficients, and its convergence towards the theoretical values, makes them useful for characterization and comparability exercises. Also, these values provide insight into the absorbance and scattering properties of the evaluated proteins. Overall, this methodology is capable of providing accurate extinction coefficients useful for development studies.

The relationship of cytotoxic and genotoxic damage with blood aluminum levels and oxidative stress induced by this metal in common carp (Cyprinus carpio) erythrocytes.

Aluminum is one of the most abundant elements in nature and is used in diverse industrial processes. As a result, it contaminates aquatic ecosystems, inducing damage on associated biota. In fish, it has been observed to induce hypoxia, hypercapnia, metabolic acidosis and respiratory arrest. Although there is little information on Al-induced cytotoxicity and DNA damage, this type of studies are essential in order to identify the mechanisms of action of this metal. The cytotoxic and genotoxic effects induced by Al on common carp (Cyprinus carpio) erythrocytes were determined in specimens exposed to 0.05, 120 and 239mgAlL(-1) in static exposure systems. Blood samples were taken at 12, 24, 48, 72 and 96h, erythrocytes were separated, and the following were evaluated: frequency of micronuclei and frequency of terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive cells, blood Al levels, lipid peroxidation, protein carbonyl content, and activity of the antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase. The results show that tested aluminum concentrations produces oxidative stress (increase in lipid peroxidation degree and oxidized proteins content, as well as decrease in antioxidant enzymes activity) and induced higher frequencies of micronuclei and TUNEL-positive cells, so this metal can be considered as a cytotoxic and genotoxic agent for erythrocytes of common carp.

Desenvolvimento foliar das culturas da soja e do feijão e de plantas daninhas

The objective of this study was to compare the emission rate and expansion of the leaves, duration of the leaf area (DLA) and the extinction coefficient (k) for the crops soybean and of the bean, and for the weeds Euphorbia heterophylla sensitive and Euphorbia heterophylla resistant to the herbicides inhibiting of the ALS enzyme, Bidens pilosa and Desmodium tortuosum. The experiment was developed in the field, in soil classified as Red-Yellow Claysoil, in the period of october of 2000 to march of 2001. Each plantspecies consisted of a treatment. The treatments were arranged in a randomized complete block design with four replications. The mensurations of the photosynthetically active radiation (PAR) were accomplished in two points of the plants: above and bellow the canopy, by means of a light ceptometer. The emission rate and the expansion of leaves was calculated at the end of the cycle of the crops. The DLA and k were calculated before and after the plant flowering. It was not observed differences in the development of the biotypes of E. heterophylla with relation to the rate of appearance of leaves, expansion rate, DLA or k. Among the cultures, the bean presented smaller leaf emission rate (0.591 / day) compared to the soybean (0.933 / day). Among the weeds, the largest leaf emission rate was with D. tortuosum (0.699 / day). The leaf expansion rate observed by the soybean was superior to all the other species (6.77 cm².dia-1). All plant species presented larger value for DLA after the flowering compared before flowering. The soybean presented larger value of k (before and after the flowering 0.52 and 0.93, respectively) compared to the other species, demonstrating high potential of interception of solar radiation.

Objetivou-se, neste trabalho, comparar a taxa de emissão e expansão das folhas, duração da área foliar (DAF) e o coeficiente de extinção (k) para as culturas da soja e do feijão e para as espécies de plantas daninhas Euphorbia heterophylla sensível e Euphorbia heterophylla resistente aos herbicidas inibidores da enzima ALS, Bidens pilosa e Desmodium tortuosum. O experimento foi desenvolvido a campo, em um Argissolo Vermelho-Amarelo, no período de outubro de 2000 a março de 2001. Cada espécie vegetal constou de um tratamento. O delineamento experimental utilizado foi o de blocos ao acaso com quatro repetições. As medições da radiação fotossinteticamente ativa (RFA) foram realizadas em dois pontos dos dosséis: acima e abaixo, por meio de um light ceptometer. A taxa de emissão e de expansão foliar foi calculada ao final do ciclo das culturas. A duração da área foliar e o coeficiente de extinção foram calculados antes e após o florescimento. Não se observaram diferenças no desenvolvimento dos biótipos de E. heterophylla quanto à taxa de aparição de folhas, taxa de expansão foliar, DAF ou k. Entre as culturas, o feijão apresentou menor taxa de emissão foliar (0,591 por dia) comparado à soja (0,933 por dia). Dentre as plantas daninhas, D. tortuosum apresentou a maior taxa de emissão foliar (0,699 por dia). A taxa de expansão foliar observada pela soja foi superior a todas as demais espécies avaliadas (6,77 cm².dia-1). Todas as espécies apresentaram maior valor para DAF após o florescimento, em comparação com a fase vegetativa. A soja apresentou maior valor de k (antes e após o florescimento 0,52 e 0,93, respectivamente) frente às demais espécies, demonstrando maior potencial de interceptação da radiação solar.

Desenvolvimento foliar das culturas da soja e do feijão e de plantas daninhas

The objective of this study was to compare the emission rate and expansion of the leaves, duration of the leaf area (DLA) and the extinction coefficient (k) for the crops soybean and of the bean, and for the weeds Euphorbia heterophylla sensitive and Euphorbia heterophylla resistant to the herbicides inhibiting of the ALS enzyme, Bidens pilosa and Desmodium tortuosum. The experiment was developed in the field, in soil classified as Red-Yellow Claysoil, in the period of october of 2000 to march of 2001. Each plantspecies consisted of a treatment. The treatments were arranged in a randomized complete block design with four replications. The mensurations of the photosynthetically active radiation (PAR) were accomplished in two points of the plants: above and bellow the canopy, by means of a light ceptometer. The emission rate and the expansion of leaves was calculated at the end of the cycle of the crops. The DLA and k were calculated before and after the plant flowering. It was not observed differences in the development of the biotypes of E. heterophylla with relation to the rate of appearance of leaves, expansion rate, DLA or k. Among the cultures, the bean presented smaller leaf emission rate (0.591 / day) compared to the soybean (0.933 / day). Among the weeds, the largest leaf emission rate was with D. tortuosum (0.699 / day). The leaf expansion rate observed by the soybean was superior to all the other species (6.77 cm².dia-1). All plant species presented larger value for DLA after the flowering compared before flowering. The soybean presented larger value of k (before and after the flowering 0.52 and 0.93, respectively) compared to the other species, demonstrating high potential of interception of solar radiation.

Objetivou-se, neste trabalho, comparar a taxa de emissão e expansão das folhas, duração da área foliar (DAF) e o coeficiente de extinção (k) para as culturas da soja e do feijão e para as espécies de plantas daninhas Euphorbia heterophylla sensível e Euphorbia heterophylla resistente aos herbicidas inibidores da enzima ALS, Bidens pilosa e Desmodium tortuosum. O experimento foi desenvolvido a campo, em um Argissolo Vermelho-Amarelo, no período de outubro de 2000 a março de 2001. Cada espécie vegetal constou de um tratamento. O delineamento experimental utilizado foi o de blocos ao acaso com quatro repetições. As medições da radiação fotossinteticamente ativa (RFA) foram realizadas em dois pontos dos dosséis: acima e abaixo, por meio de um light ceptometer. A taxa de emissão e de expansão foliar foi calculada ao final do ciclo das culturas. A duração da área foliar e o coeficiente de extinção foram calculados antes e após o florescimento. Não se observaram diferenças no desenvolvimento dos biótipos de E. heterophylla quanto à taxa de aparição de folhas, taxa de expansão foliar, DAF ou k. Entre as culturas, o feijão apresentou menor taxa de emissão foliar (0,591 por dia) comparado à soja (0,933 por dia). Dentre as plantas daninhas, D. tortuosum apresentou a maior taxa de emissão foliar (0,699 por dia). A taxa de expansão foliar observada pela soja foi superior a todas as demais espécies avaliadas (6,77 cm².dia-1). Todas as espécies apresentaram maior valor para DAF após o florescimento, em comparação com a fase vegetativa. A soja apresentou maior valor de k (antes e após o florescimento 0,52 e 0,93, respectivamente) frente às demais espécies, demonstrando maior potencial de interceptação da radiação solar.

Caracterizacion de nueve genotipos de maiz (Zea mays L.) en relacion a area foliar y coeficiente de extincion de luz

Se caracterizaron nueve materiales genéticos de maíz (Arichuna, Baraure, Braquítico, Experimental-2, Foremaíz PB, FM-6, Obregón, Proscca-71 y Tocorón), en relación con área promedio de hoja por planta, área foliar total por planta (AFT), índice de área foliar (IAF), y coeficiente de extinción de luz (K) a 0,50 m, 1,00 m, 1,50 m, 2,00 m y 2,50 m de altura de la planta (medidos a partir del suelo). Además, estudios de correlación y regresión simple fueron hechos entre rendimiento (R) y IAF. Se encontraron rangos de variación para las diversas variables: Area promedio de hoja por planta(471cm² para Foremaiz PB y 606 cm² para Baraure); AFT ( 5 327cm² en Foremaiz PB y 8 411 cm² para Braquítico); IAF (4,26, Foremaiz PB y 6,67, Braquítico); K (0,23 para Braquítico y 0,42, Arichuna); rendimiento (2 877 kg.ha-1, Braquítico y 4 784 kg.ha-1 en Tocorón). La relación entre rendimiento y IAF no fue significativa(r = 0,07). La asociación de IAF y K file muy bien descrita por la ley de Beer.

A field experiment was carried out to evaluate nine corn genotypes (Arichuna, Baraure, B raquitico, Expe-rimental-2, Foremaiz PB, FM-6, Obregón, Proseca-71 and Tocorón) in relation to: mean leaf area per plant, total leaf area per plant (TLA), leaf area index (LAI), grain yield (Y) and light extinction coefficient (K) at 0.50m, 1.00m, 1.50m, 2.00m and 2.50m of plant height (from soil to flag leaf). Also, correlation and single regression between LAI and yield was performed. Significant genotypical differences for all variables were found, except for mean leaf area per plant Ranging was: mean leaf area per plant (471 cm² for Foremaiz PB and 606 cm² for Baraure); TLA (5,327 cm² for Foremaiz PB and 8,411 for Braquítico); LAI (4.26, Foremaiz PB and 6.67, Braquítico); K (0.23 for Braquítico and 0.42, Arichuna); Y (2, 877, Braquítico and 4,784 kg.ha-1 for Tocoron).The relationship between Y and LAI was not significant (r = 0.07). The relationship of LAI and K was described very well by Beer's law.

Foram caracterizados nove materiais genéticos de milho (Arichuna, Baraure, Braquítico, Experimental-2, Foremaíz PB, FM-6, Obregón, Proseca-71 y Tocorón) com relação a área foliar média de folhas por planta(AF), área foliar total por planta (AFT), índice de área foliar (IAF) e coeficiente de extinção de luz (K) a 0,50m, 1,00m, 1,50m, 2,00m e 2,50m de altura (a partir do solo). Foram encontrados os seguintes intervalos de variação para as diversas variáveis: área média de folhas por planta (471 cm² para Foremaíz PB e 606 cm² Baraure); área foliar total por planta: 5 327 cm² (Foremaiz PB) e 8 411 cm² (Braquítico), índice de área foliar: 4,26 (Foremaiz PB) e 6,67 (Braquítico); coeficiente de extinção de luz: 0,23 (Braquítico) e 0,42 (Arichuna); rendimento: 2 877 kg.ha-1 (Braquítico) e 4 784 kg.ha-1 (Tocorón). Não foi encontrada relação entre o rendimento e o IAF (r = 0,07), e a associação do IAF e K foi muito bem explicada pela lei de Beer.

Caracterizacion de nueve genotipos de maiz (Zea mays L.) en relacion a area foliar y coeficiente de extincion de luz

Se caracterizaron nueve materiales genéticos de maíz (Arichuna, Baraure, Braquítico, Experimental-2, Foremaíz PB, FM-6, Obregón, Proscca-71 y Tocorón), en relación con área promedio de hoja por planta, área foliar total por planta (AFT), índice de área foliar (IAF), y coeficiente de extinción de luz (K) a 0,50 m, 1,00 m, 1,50 m, 2,00 m y 2,50 m de altura de la planta (medidos a partir del suelo). Además, estudios de correlación y regresión simple fueron hechos entre rendimiento (R) y IAF. Se encontraron rangos de variación para las diversas variables: Area promedio de hoja por planta(471cm² para Foremaiz PB y 606 cm² para Baraure); AFT ( 5 327cm² en Foremaiz PB y 8 411 cm² para Braquítico); IAF (4,26, Foremaiz PB y 6,67, Braquítico); K (0,23 para Braquítico y 0,42, Arichuna); rendimiento (2 877 kg.ha-1, Braquítico y 4 784 kg.ha-1 en Tocorón). La relación entre rendimiento y IAF no fue significativa(r = 0,07). La asociación de IAF y K file muy bien descrita por la ley de Beer.

A field experiment was carried out to evaluate nine corn genotypes (Arichuna, Baraure, B raquitico, Expe-rimental-2, Foremaiz PB, FM-6, Obregón, Proseca-71 and Tocorón) in relation to: mean leaf area per plant, total leaf area per plant (TLA), leaf area index (LAI), grain yield (Y) and light extinction coefficient (K) at 0.50m, 1.00m, 1.50m, 2.00m and 2.50m of plant height (from soil to flag leaf). Also, correlation and single regression between LAI and yield was performed. Significant genotypical differences for all variables were found, except for mean leaf area per plant Ranging was: mean leaf area per plant (471 cm² for Foremaiz PB and 606 cm² for Baraure); TLA (5,327 cm² for Foremaiz PB and 8,411 for Braquítico); LAI (4.26, Foremaiz PB and 6.67, Braquítico); K (0.23 for Braquítico and 0.42, Arichuna); Y (2, 877, Braquítico and 4,784 kg.ha-1 for Tocoron).The relationship between Y and LAI was not significant (r = 0.07). The relationship of LAI and K was described very well by Beer's law.

Foram caracterizados nove materiais genéticos de milho (Arichuna, Baraure, Braquítico, Experimental-2, Foremaíz PB, FM-6, Obregón, Proseca-71 y Tocorón) com relação a área foliar média de folhas por planta(AF), área foliar total por planta (AFT), índice de área foliar (IAF) e coeficiente de extinção de luz (K) a 0,50m, 1,00m, 1,50m, 2,00m e 2,50m de altura (a partir do solo). Foram encontrados os seguintes intervalos de variação para as diversas variáveis: área média de folhas por planta (471 cm² para Foremaíz PB e 606 cm² Baraure); área foliar total por planta: 5 327 cm² (Foremaiz PB) e 8 411 cm² (Braquítico), índice de área foliar: 4,26 (Foremaiz PB) e 6,67 (Braquítico); coeficiente de extinção de luz: 0,23 (Braquítico) e 0,42 (Arichuna); rendimento: 2 877 kg.ha-1 (Braquítico) e 4 784 kg.ha-1 (Tocorón). Não foi encontrada relação entre o rendimento e o IAF (r = 0,07), e a associação do IAF e K foi muito bem explicada pela lei de Beer.