Artificial neural network approach for predicting the sesame ( Sesamum indicum L.) leaf area: A non-destructive and accurate method

Abstract

The estimative of the leaf area using a nondestructive method is paramount for successive evaluations in the same plant with precision and speed, not requiring high-cost equipment. Thus, the objective of this work was to construct models to estimate leaf area using artificial neural network models (ANN) and regression and to compare which model is the most effective model for predicting leaf area in sesame culture. A total of 11,000 leaves of four sesame cultivars were collected. Then, the length (L) and leaf width (W), and the actual leaf area (LA) were quantified. For the ANN model, the parameters of the length and width of the leaf were used as input variables of the network, with hidden layers and leaf area as the desired output parameter. For the linear regression models, leaf dimensions were considered independent variables, and the actual leaf area was the dependent variable. The criteria for choosing the best models were: the lowest root of the mean squared error (RMSE), mean absolute error (MAE), and absolute mean percentage error (MAPE), and higher coefficients of determination (R ²). Among the linear regression models, the equation $\hat{\mathrm{y}}=0.515+0.584*\mathrm{L}\mathrm{W}$ was considered the most indicated to estimate the leaf area of the sesame. In modeling with ANNs, the best results were found for model 2-3-1, with two input variables (L and W), three hidden variables, and an output variable (LA). The ANN model was more accurate than the regression models, recording the lowest errors and higher R ² in the training phase (RMSE: 0.0040; MAE: 0.0027; MAPE: 0.0587; and R ²: 0.9834) and in the test phase (RMSE: 0.0106; MAE: 0.0029; MAPE: 0.0611; and R ²: 0.9828). Thus, the ANN method is the most indicated and accurate for predicting the leaf area of the sesame.

Highlights

• •

  Artificial neural network model was more suitable to predict sesame leaf area.

• •

  The regression model $\hat{\mathrm{y}}=0.515+0.584*\mathrm{L}\mathrm{W}$ was the best to estimate leaf area.

• •

  ANN model was more accurate in the training and testing phase than the linear regression models.