Análise do rendimento do milho com atraso na semeadura no planalto catarinense, simulado com o modelo CERES-Maize.

Abstract

This work had as objective to investigate the delay effects in sowing date on corn establishment, cycle duration and corn yield, through computer simulations using CERES-Maize model, in order to help agrarian producers, from the Mountainous Area of Santa Catarina, Brazil, to take better decisions on it. According to the season it is cultivated, corn seed with late sowing is usually exposed to larges risks of losses for frost and deficiency of water resources than that one cultivated during the recommended season, so reaching a smaller productivity potential and tending to increase its cycle. Computer simulations showed that: 1) the risks on corn establishment increased due to delay of sowing during the studied years; 2) in some years the cycles were drastically affected for lower temperatures; 3) cycle durations were longer when confronted with low temperatures, showing that that model was sensitive to this factor; 4) corn income decreased when cycles were confronted with low temperatures, water deficiency and low solar radiation; 5) potential incomes averaged 4955kg ha-1, and under natural rain conditions averaged 2490kg ha-1, during all months analyzed (October to March); 6) besides January, it would not be viable the exploration of this cultivate because of the high risk of crop frustration associated to the same ones, due to thermal conditions (low temperatures and frost).