Characteristics of castor bean cultivars according to the environmental crop and sowing season in Rio Grande do Sul State, Brazil

Castor bean (Ricinus communis L.) is an oleaginous plant with annual cycle and occasionally biennial cycle in tropical areas, with mean cycle of 150 days for the majority of annual cultivars and 120 to 130 days for annual early cultivars. The objective of this study was to evaluate the agronomic characteristics of castor cultivars according to environmental crop and sowing season. The experiment was conduced at Embrapa china Temperado - Pelotas/RS, in two places. The castor cultivars used in this research were 'Al Guarany 2002', 'IAC 80', 'MC 226' and 'BRS 188 Paraguacu'. which were sown in two sowing times: the first was in early November (between 1(st) and 5(st)) and the second was in early December (between 1(st) and 5(st)). Each sowing season was constituted of 12 experimental units, distributed in three random blocks. It was evaluated the emergency, plant height and first spike insertion, flowering and hat-vest time, pest and disease attacks. The WinStat program Version 2.0 was used for data statistical analysis. There was a significant difference among cultivar behaviors between the environmental crops and sowing seasons. The second sowing season provided a larger plant and first spike in sects higher It also promoted retardation in the flowering and harvesting time. The differences among cultivars, between the two environmental crops, were clearer in the pest and disease attacks, but also in morphologic characteristics of castor plant.