Growth models of peach fruit prunus persica (L) in three handling systems

This study was conducted in orchards located in Durango, México, during 2013, at a site with an average annual precipitation of 450mm and mean temperature of 17.7oC. The goal was to evaluate three non-linear models: logistic, monomolecular and Gompertz, to simulate peach fruit growth as measured by polar (PD) and equatorial (ED) diameters using the Creole peach. The first treatment (T1) received pruning, irrigation, fertilization (PIF) and application of organic insecticides. The second treatment (T2) received only PIF, and the control (T3) received only irrigation. Parameters measured included PD, ED and inflection points (IP). The models were evaluated using the square sum of errors (SSE), coefficient of determination (R²), and the Akaike criterion; the Student test t was used to compare the coefficients among models. The smallest values of SSE and Akaike indicated that the monomolecular model was the best fit for PD and ED with R²= 0.9998, 0.9997 and 0.9998 for T1, T2 and T3, respectively. The largest diameter was found in model for T1 and differed from the models for T2 and T3. Simulation of peach fruit growth with the monomolecular model allows for the description of diameter growth rates with reference to IPs and should facilitate the planning of agronomic and pest control tasks.