Épocas de semeadura do milho “safrinha”, no Estado do Paraná, com menores riscos climáticos

Planting dates with lower climatic risk, for maize grown, during the winter season "safrinha", in Parana State, Brazil. The maize crop, Zea mays L. (Poaceae), grown during the winter season "safrinha" in Parana State, southern Brazil, can be exposed to severe yield losses caused by unfavorable climatic events, depending on the planting date. In this paper, a methodology was adapted to assess the risk of frost during the crop cycle, with emphasis on the period between flowering and maturation, and the risk of water deficit during plant establishment and at flowering. Frost risk during the 30 days before maturation was considered as the most restrictive factor. Associating frost and water deficit risk, it was possible to identify eight distinct regions, with homogeneous planting dates of lower risk ranging from January to March.