Harvest seasons and physiological quality of crambe seeds

Abstract

The objective of this study was to evaluate different harvest seasons on the seed quality of crambe, cultivar FMS Brilhante. The experiment was carried out at Experimental area of the Montes Claros State University - UNIMONTES in Janaúba-MG, on September 3, 2011. The first raceme harvest was performed 14 days after flowering, when approximately 50% of the plants showed full flowering. The other harvests were performed every six days, making a total of five harvests. Accumulation of thermal units in degrees day during time intervals was also determined. The collected racemes were taken to the Laboratory of Seed Analysis at UNIMONTES, when they remained under ambient conditions until beginning the analyses. Seeds were evaluated as for water content, germination and vigor (dry seed weight, thousand seeds weight, seedling emergence, and emergence speed). The experimental design was completely randomized, with five harvest seasons, which composed the treatments, and four replications. Crambe seeds present post-harvest dormancy. The maximum dry matter accumulation (physiological maturity) occurred 26 days after flowering. In conclusion, the best time to harvest crambe seeds, cultivar FMS Brilhante, with higher physiological quality (maximum germination and vigor) occurs within 14 to 26 days after flowering, which is a thermal sum 1111,1 to 1302, 15 degree day.