The leaf has a vital role in the functions of the plant, being responsible for photosynthesis and gas exchange. Thus, the objective of this study was to fit a mathematical equation model to estimate the leaf area of M...The leaf has a vital role in the functions of the plant, being responsible for photosynthesis and gas exchange. Thus, the objective of this study was to fit a mathematical equation model to estimate the leaf area of Maytenus obtusifolia Mart. through the linear dimensions of the leaves. For that, six hundred and fifteen healthy leaves were collected from plants belonging to the Federal University of Espírito Santo, São Mateus Campus, in the municipality of São Mateus, located in the north of the State of Espírito Santo, Brazil. All leaves were digitized and the images processed using the ImageJ®software, obtaining the measurements of the maximum length of the main midrib (L), the maximum width of the leaf blade (W) and the real leaf area (RLA) of each sheet. Subsequently, the product of length and width multiplication (LW) was also obtained. 500 sheets were randomly separated for the generation of models of mathematical equations and their respective coefficient of determination (R2), where RLA was used as dependent variable as function of L, W or LW as independent variable. Based on the models generated, a 115 leaf sample was used for validation, where the L, W and LW values of this sample were replaced in the adjusted equations, thus obtaining the estimated leaf area (ELA). A comparison of the means of RLA and ELA was performed by Student’s t test at 5% probability. We also calculated the mean absolute error (MAE), the root mean square error (RMSE) and the Willmott index (d). The best equation was defined by the following criteria: non-significant values of RLA and ELA averages, R2 and index d closest to unit, and MAE and RMSE values with greater proximity to zero. The quadratic model equation represented by ELA=0.18122798+0.72847767(LW)+0.00002789(LW)2 generated by multiplying the length with the width (LW) is the most suitable for the estimation of the leaf area of Maytenus obtusifolia Mart., in a fast, safe and non-destructive way.展开更多
The objective of this study was to determine the sample size needed to evaluate characters of mature fruits of yellow mombin (Spondias mombin L.). 100 fruits were evaluated from plants grown under a shading system. In...The objective of this study was to determine the sample size needed to evaluate characters of mature fruits of yellow mombin (Spondias mombin L.). 100 fruits were evaluated from plants grown under a shading system. In the laboratory, these fruits were measured by the characters: longitudinal length (mm);equatorial diameter (mm);fruit mass (g);yield of pulp (%);total soluble solids—TSS (°Brix);titratable acidity—TA (% citric acid) and ratio (TSS/TA), being calculated the measures of central tendency and dispersion, and verified normality. Next, the sample size for each character was determined. For experimental evaluation of cajámirim fruits, considering an accuracy of 10% around the mean, 40 fruits per treatment should be evaluated, considering a completely randomized experiment.展开更多
The reduction of foliar area can cause yield reduction in common bean crops. The objective of this work was to verify which is the effect of different defoliation levels realized in several development stages of commo...The reduction of foliar area can cause yield reduction in common bean crops. The objective of this work was to verify which is the effect of different defoliation levels realized in several development stages of common bean (Phaseolus vulgaris L. cv. Goytacazes) over yield, weight of 100 seeds and number of pods per plant. The experimental design was randomized blocks, in a split-plot arrangement with five replications. The plot corresponded to the five defoliation epochs (first trifoliate leaf, flowering, pods formation, pods filling, and dry pods). In each plot, the split plot was represented by the four defoliation levels (0%, 33%, 67% and 100%). It was observed a decrease of yield for all levels defoliation considering all development stages, except for dried pods. The highest decrease was detected for flowering and pods formation. Through the regression analysis got a greater reduction in yield with 100% defoliation made at 42 days after emergence. The evaluation parameter that showed better relation with yield was a number of pods per plant.展开更多
文摘The leaf has a vital role in the functions of the plant, being responsible for photosynthesis and gas exchange. Thus, the objective of this study was to fit a mathematical equation model to estimate the leaf area of Maytenus obtusifolia Mart. through the linear dimensions of the leaves. For that, six hundred and fifteen healthy leaves were collected from plants belonging to the Federal University of Espírito Santo, São Mateus Campus, in the municipality of São Mateus, located in the north of the State of Espírito Santo, Brazil. All leaves were digitized and the images processed using the ImageJ®software, obtaining the measurements of the maximum length of the main midrib (L), the maximum width of the leaf blade (W) and the real leaf area (RLA) of each sheet. Subsequently, the product of length and width multiplication (LW) was also obtained. 500 sheets were randomly separated for the generation of models of mathematical equations and their respective coefficient of determination (R2), where RLA was used as dependent variable as function of L, W or LW as independent variable. Based on the models generated, a 115 leaf sample was used for validation, where the L, W and LW values of this sample were replaced in the adjusted equations, thus obtaining the estimated leaf area (ELA). A comparison of the means of RLA and ELA was performed by Student’s t test at 5% probability. We also calculated the mean absolute error (MAE), the root mean square error (RMSE) and the Willmott index (d). The best equation was defined by the following criteria: non-significant values of RLA and ELA averages, R2 and index d closest to unit, and MAE and RMSE values with greater proximity to zero. The quadratic model equation represented by ELA=0.18122798+0.72847767(LW)+0.00002789(LW)2 generated by multiplying the length with the width (LW) is the most suitable for the estimation of the leaf area of Maytenus obtusifolia Mart., in a fast, safe and non-destructive way.
文摘The objective of this study was to determine the sample size needed to evaluate characters of mature fruits of yellow mombin (Spondias mombin L.). 100 fruits were evaluated from plants grown under a shading system. In the laboratory, these fruits were measured by the characters: longitudinal length (mm);equatorial diameter (mm);fruit mass (g);yield of pulp (%);total soluble solids—TSS (°Brix);titratable acidity—TA (% citric acid) and ratio (TSS/TA), being calculated the measures of central tendency and dispersion, and verified normality. Next, the sample size for each character was determined. For experimental evaluation of cajámirim fruits, considering an accuracy of 10% around the mean, 40 fruits per treatment should be evaluated, considering a completely randomized experiment.
文摘The reduction of foliar area can cause yield reduction in common bean crops. The objective of this work was to verify which is the effect of different defoliation levels realized in several development stages of common bean (Phaseolus vulgaris L. cv. Goytacazes) over yield, weight of 100 seeds and number of pods per plant. The experimental design was randomized blocks, in a split-plot arrangement with five replications. The plot corresponded to the five defoliation epochs (first trifoliate leaf, flowering, pods formation, pods filling, and dry pods). In each plot, the split plot was represented by the four defoliation levels (0%, 33%, 67% and 100%). It was observed a decrease of yield for all levels defoliation considering all development stages, except for dried pods. The highest decrease was detected for flowering and pods formation. Through the regression analysis got a greater reduction in yield with 100% defoliation made at 42 days after emergence. The evaluation parameter that showed better relation with yield was a number of pods per plant.
