Controlled deterioration test for evaluation of sunn hemp seed vigor
The controlled deterioration test is efficient for seed vigor evaluation of several species. However, the procedures conditions are incipient, especially in respect to tropical forages such as sunn hemp, which still does not have a standardized procedure. The objective of this research was to adjust the procedures for a controlled deterioration test in Crotalaria juncea L. seeds. For this, five commercial seed lots were evaluated for water content and initial physiological potential (germination test, first germination count, germination speed index, saturated salt accelerated aging with NaCl, electrical conductivity and seedling field emergence). For controlled deterioration test, the initial seed moisture content was adjusted to 18, 21 and 24% and, subsequently, the samples were exposed at 45 °C during 24 hours. Seed germination test was conducted with the use of sand as substrate. Evaluations were performed on the fourth, fifth and sixth day after sowing. The controlled deterioration test for sunn hemp seeds should be performed with 24% seed moisture content, at 45 °C during 24 hours, and the test evaluation on the fourth day after sowing.