Controlled deterioration test determines vigour and predicts field emergence in pepper seed lots

Abstract

The controlled deterioration (CD) test is a vigour test for small seeded vegetables. Thirteen pepper (Capsicum annuum L.) seed lots were deteriorated at 24% seed moisture content for 24, 48, or 72 hours at three different temperatures (41, 43 and 45°C), to determine the optimum test conditions, in terms of temperature and ageing period. Germination data after CD were subsequently correlated with data for the standard germination test, cool germination test at 15 and 18°C and field emergence. The standard germination of seed lots ranged from 85% to 95%, while the field emergence ranged from 76% to 94%. CD germination for all temperatures and time combinations was significantly correlated with both field emergence and cool germination at 15°C. However, the highest correlation was found between the CD germination after 24 h at 45°C and field emergence (r=0.905). Thus, controlled deterioration clearly identified differences in seed lot vigour that were reflected in field emergence. It is suggested that for the controlled deterioration test, pepper seeds should be at 24% MC and deteriorated at 45°C for 24 hours.