Graus-dia, temperatura base e coeficientes de cultura para cafeeiros arabica vem fase de implantaÃÃo / Degree-day, base temperature and crop coefficients for arabic coffee plants in implantation phase.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

This work had as purpose the determination of the inferior and superior base temperature as well crop coefficients, Kc for two cultivars of Arabic coffee, Acaià Cerrado(MG-1474) and Ruby (MG-1192), , in way to allow the representation of the growing degree-day (GDD) based crop coefficients.The experiment was carried out in the âFederal University of Lavrasâ (UFLA) in the period of March 2003 to September 2004, in an outline of lines and columns, constituted of 20 plots 10 with Acaià Cerrado and 10 with Ruby.Each plot was constituted of 9 plants in spacing of 3.5 x 0.80 m, identified by its transplanting date. It was used for statistical analysis a study with regression. and for the comparisons among the regressions, was used the procedure described in Snedecor &Cochran (1989). The values of GDD, were obtained with the methodology presented by Ometto (1981), compared with the methods presented by Arnold (1959), Snyder (1985) and Dufault (1997). The temperatures, 12,9oC for the inferior base and 32,4oC for the superior base, after comparisons among the methods: least standard deviation in degree-day and days, coefficient of variation in degree-day and regression coefficient. The values of crop coefficients, Kc, for both cultivars up to 4200 GDD were 0.20, 0.89 and 0.48, as minimum, maximum and medium Kc respectively. The vegetative growth of both cultivars, the canopy and stem diameter, and length of the lateral branch had a good adjustment with GDD. Each variable but plant height, can be represented by a single 3o degree polynomial equation for both cultivars. The plant height, up to 2500 GDD for both cultivars, had a increasing and parallel development; from that point on the cultivar Ruby presented a reduction in the growth rate. The variable growth, in comparison to the others, was represented by a different way, individually, for two 3o degree polynomials equations of. All the adjusted variables as a function of GDD presented good performace.

ASSUNTO(S)

engenharia agricola coffee meteorology cafÃ; temperatura; meteorologia temperature

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