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.
RESUMOO aproveitamento de resíduos industriais na agricultura possibilita à discussão de um relevante tema voltado a sustentabilidade das indústrias e economia aos produtores que vislumbram a substituição de adubos minerais por novas alternativas. O lodo de curtume é um resíduo rico em elementos essenciais aos vegetais com potencial de uso na forma de fertilizantes, portanto, deve ser testado em culturas relevantes, como a do maracujazeiro-amarelo, o qual está entre as principais frutas tropicais comercializadas no Brasil. Objetivou-se com este trabalho avaliar o efeito da adubação foliar com lodo de curtume líquido em diferentes dosagens na produção de mudas de maracujá-amarelo (Passiflora edulis f. flavicarpa). Para tanto, utilizou-se o delineamento em blocos casualizados com seis tratamentos e seis repetições. Os tratamentos constaram de diferentes diluições de lodo de curtume em água, aplicados semanalmente na parte aérea das mudas em desenvolvimento. Foi observado que a aplicação de doses acima de 263 mL lodo de curtume na parte aérea das plantas proporcionou as mudas de maracujá-amarelo desenvolvimento igual ou superior ao convencional na maioria das características avaliadas. O aumento das doses de lodo de curtume proporcionou as mudas ganhos lineares em suas características de desenvolvimento, sendo possível a utilização de lodo de curtume para fins de adubação foliar de mudas de maracujazeiro como fonte alternativa a adubos químicos. Palavra-chaves:Resíduo orgânico, Propagação, Fruticultura.
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
The occurrence of degraded areas worldwide grows each year and measures must be taken to mitigate degradation and to recover these areas. The aim of this study was to assess the effect of soil preparation and NPK levels on the growth of five native species of the Atlantic Rainforest in clay extraction area. The experimental design was randomized block in a split-split plot arrangement with four replications. Subsoiling and scarification soil preparation represented main plots. Doses of NPK 04-14-08: 0; 40; 80;160; and 320 g pit-1 represented subplots and Atlantic Rainforest native species represented sub-subplots. Absolute growth rate, stem diameter and number of leaves were evaluated, 210 days after planting. The type of soil preparation did not influence the development of the species. The best dose for Dalbergia ecastaphyllum, Inga laurina, Protium heptaphyllum and Psidium cattleyanum were 176.49, 150.18, 199.25 and 166.48 g pit-1 of NPK, respectively. Schinus terebinthifolius was highly responsive to planting fertilization, being recommended 320 g pit-1 of NPK. All species are indicated for area recovery.
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