J. R. M. Pezzopane

Modelos agrometeorológicos de estimativa da duração do estádio floração-maturação para três cultivares de café arábica

Models that consider the climatic effects to the physiologic processes of the phenology are fundamental for obtaining agrometeorological models more consistent to estimate duration of the flowering-maturation coffee growth stage and consequently better coffee grain yield estimates. The main objective was to obtain the parametrization and validation of different agrometeorological models that quantify the duration of the flowering-maturation stage for three arabica coffee cultivars. Phenological data were collected concerning Mundo Novo, Catuai, and Obata IAC 1669-20 cultivars from the experimental studies between the growing seasons 2001/02 to 2007/08 at Agronomic Institute (IAC/APTA), located at Campinas and Mococa, Sao Paulo State, Brazil. The growing seasons from 2001/02 to 2004/05 were used for the parametrization of the models, and from 2005/06 to 2007/08 were reserved for the validations. Five different thermal sums were used to estimate the duration of the flowering-maturation stage. Three based on evapotranspiration: potential (ETp), actual (ETr) and a combination between ETr and ETp (ETr-ETp); and two based on classic growing degree-days (GD) and a corrected by the water availability factor (GDcorr) during the fructification period. Results indicated that models considering correction for water availability (ETr and GDcorr) presented better results with estimative of the duration of the flowering-maturation stage with larger consistence than the other sums. The accumulation models considering ETr values of 746 mm, 762 mm, and 799 mm and GD corr (base temperature of 10.5°C) values of 2733 GDD, 2816 GDD, and 3008 GDD, respectively for Mundo Novo, Catuai, and Obata IAC 1669-20 cultivars, can be considered more consistent parameter for flowering-maturation phase estimation. The parametrized models were tested with independent years, and presented good estimates. The results confirm the need of the water availability factor to be considered for the quantification of the required thermal sums.