Rapeseed planting date in southeastern Rio Grande do Sul, Brazil

Abstract

The search for un alternative crop for the winter season, the use of the oil for fuel and food purposes, and the utilization of protein meal as feedstuff souce have promoted the rapeseed (Brassica napus L. var. oleifera Metzg.) crop in Rio Grande do Sul State, Brazil, in 80's; but certain factors limit yield. Apart from diseases and crop regionalization, a limiting constraint is the planting date. In order to study this subject in Pelota's region, four rapeseed varieties were seeded from May to August 1983, and from June to November 1984, on a Red Yellow Podzolic soil at the Fazenda da Palma Experiment Station, Federal University of Pelotas, Capão do Leão county (31^o 52' S), RS. Field trials and bench tests were performed to evaluate planting date effect on growth duration, oil level, and seed and oil yield. The early planting (May and June) proportionates better seed and oil yields, respectively 33 to 500%, and 25 to 800% when compared to the later one (August and November), although the elongation of growth duration. This practice promotes additionaly the soybean succession cropping and raw-material to oil industries in off-season (from November to February).