The crop of castor bean can be used like raw material for renewable energy, however, becomes necessary the use of agricultural machines adapted to its harvest. During the crop growth racemes are produced under different environmental conditions which can cause variations in productivity of the crop. The purpose of this work was to evaluate important agronomic characteristics to mechanical harvest as well as the effect of time of harvest in productivity of castor bean. The experimental design was arranged in a randomized block design with eleven treatments and five replications, with cultivar IAC 2028 , during the agricultural year of 2005/06 at the Centro Experimental Central, Instituto Agronômico (IAC), Campinas, São Paulo State, Brazil. Seed yield, number of fruits and seeds per raceme and mass of a thousand seeds were evaluated. In the evaluation of the agronomic characteristics was observed a great variability among the plants, what can complicate mechanical harvest. The results showed that the secondary raceme was the most influence to total productivity and the harvest of the racemes, fruits and seeds, in the conditions of this experiment, can be performed at only time with no decrease in yield.
Ricinus communis L.; racemes; physiological maturity
