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The objective of this study was to obtain mathematical models to estimate non-destructively the fruit mass of pear cv. ‘Triunfo’. To this end, 128 fruits from all developmental stages collected at three different times were used. Fruits were measured for maximum length (L), maximum width (W) and observed mass (OM). For the adjustment, with a sample of 100 fruits, the models first degree linear, quadratic and power were tested, in which the OM was used as the dependent variable in function of L and W. From a sample of 28 fruits, separated for this purpose the equations were validated. Thus, it indicates an equation of the quadratic model represented by EM = 36.020218 – 3.067232(W) + 0.082568(W)2  using from the measurement of the largest fruit width (W), as the most accurate to estimate the fruit mass of pear cv. ‘Triunfo’.

The objective of the present study was to test and establish mathematical models to estimate the leaf area of Garcinia brasiliensis Mart. through linear dimensions of the length, width and product of both measurements. In this way, 500 leaves of trees with age between 4 and 6 years were collected from all the cardinal points of the plant in the municipality of São Mateus, North of the State of Espírito Santo, Brazil. The length (L) along the main midrib, the maximum width (W), the product of the length with the width (LW) and the observed leaf area (OLA) were obtained for all leaves. From these measurements were adjusted linear equations of first degree, quadratic and power, in which OLA was used as dependent variable as function of L, W and LW as independent variable. For the validation, the values of L, W and LW of 100 random leaves were substituted in the equations generated in the modeling, thus obtaining the estimated leaf area (ELA). The values of the means of ELA and OLA were tested by Student’s t test 5% of probability. The mean absolute error (MAE), root mean square error (RMSE) and Willmott’s index d for all proposed models were also determined. The choice of the best model was based on the non significant values in the comparison of the means of ELA and OLA, values of MAE and RMSE closer to zero and value of the index d and coefficient of determination (R2) close to unity. The equation that best estimates leaf area of Garcinia brasiliensis Mart. in a way non-destructive is the power model represented by por ELA = 0.7470(LW)0.9842 and R2 = 0.9949.

The objective of this study was to determine mathematical equations that estimate the leaf area of jackfruit (Artocarpus heterophyllus) in an easy and non-destructive way based on linear dimensions. In this way, 300 leaves of different sizes and in good sanitary condition of adult plants were collected at the Federal Institute of Espírito Santo, Campus Itapina, located in Colatina, municipality north of the State of Espírito Santo, Brazil. Were measured The length (L) along the midrib and the maximum leaf width (W), observed leaf area (OLA), besides the product of the multiplication of length with width (LW), length with length (LL) and width with width (WW). The models of linear equations of first degree, quadratic and power and their respective R2 were adjusted using OLA as dependent variable in function of L, W and LW, LL and WW as independent variable. The data were validated and the estimated leaf area (ELA) was obtained. The means of ELA and OLA were compared by Student’s t test (5% probability) and were evaluated by the mean absolute error (MAE) and root mean square error (RMSE) criteria. The choice of the best model was based on non-significant comparative values of ELA and OLA, in addition to the closest values of zero of EAM and RQME. The jackfruit leaf area estimate can be determined quickly, accurately and non-destructively by the linear first-order model with LW as the independent variable by equation ELA = 1.07451 + 0.71181(LW).

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 (R 2), 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, R 2 and index d closest to unit, and MAE and RMSE values with greater proximity to zero. The quadratic model equation

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The present study had as objective to determine mathematical equations to estimate the leaf area of pear cv. 'Triunfo' using linear dimensions of the leaves. For that, 300 healthy leaves of different sizes from each quadrant of plants from the small farm of Boa Vista located in the city of Montanha, at the northern side of the State of Espírito Santo, Brazil were used. The length (L) along the main vein was measured, along with the maximum width (W) of the leaf blade and observed leaf area (OLA), in addition to the product of the length and width (LW) of each leaf. From these measurements models of linear equations of first degree, quadratic and power were adjusted and their respective R 2, using OLA as dependent variable and L, W and LW as independent variable. Based on the proposed equations, the data were validated obtaining the estimated leaf area (ELA). The mean of the ELA and OLA were compared by Student t test 5% probability. The mean error (E), the mean absolute error (MAE) and the root mean squared error (RMSE) was also used as validation criterion. The best equation model was defined based on the non-significant values from the comparison of means of ELA and OLA, E, MAE and RMSE values closer to zero and highest R 2 . The leaf area of pear cv. 'Triunfo' can be estimated by the equation ELA = -0.432338 + 0.712862(LW) non-destructively and with a high degree of precision.

Performing an adequate irrigation management for the production of papaya seedlings is essential to obtain plants that express all their genetic potential. For this reason, this work aimed to evaluate the effect of different irrigation depths on the growth and quality of papaya type 'Tainung 01' seedlings. The study took place at the Federal Institute of Espírito Santo, Campus Itapina, located in the in Colatina, in the Northwest region of the State of Espírito Santo, Brazil. The experimental design was completely randomized with 25 repetitions for each treatment. The treatments consisted on the application of six irrigation depths: 4, 6, 8, 10, 12 and 14 mm d -1. The seedlings were evaluated at 65 days after planting for the following morphological characteristics: plant height, stem diameter, number of leaves, leaf area, dry mass of the aerial part, dry mass of the root system, total dry mass and Dickson quality index. The irrigation depth of 9.16 mm d -1 had a higher Dickson quality index attesting a higher quality of seedlings, being the most suitable for the production of papaya 'Tainung 01' seedlings.