FRUIT MATURITY, STORAGE AND POSTHARVEST MATURATION TREATMENTS AFFECT BELL PEPPER (CAPSICUM-ANNUUM-L) SEED QUALITY

Some peppers (Capsicum sp.) exhibit a primary seed dormancy at harvest . This study was designed to examine the effect of fruit maturity, dry and moist seed storage and seed postharvest maturation treatments on the seed germination of four bell pepper cultivars (Capsicum annuum L. , cultivars 'Early Calwonder', 'Resistant Giant No. 4', 'VR2' and 'Yol o Wonder'). In 1987 and 1988, fruits were harvested 30 (mature green), 40 (breaker), 50 (mature red) and 60 (over-mature red) days post-anth esis (dpa), and seeds were extracted for dry storage treatments, or al lowed to remain in fruits for postharvest maturation treatments of 0, 7, 14, 21 and 28 day periods. In 1988, seeds were also stored over wat er or saturated salt solutions which provided relative humidities of 7 , 51 and 97.5% to determine the influence of seed moisture during seed storage. Seeds from red and over-mature red (50 dpa and 60 dpa, respe ctively) fruit generally had greater dry weights and higher germinatio n percentages relative to seeds from less mature fruits. Seeds extract ed from mature green (30 dpa) fruit did not germinate regardless of st orage time. Seed prostharvest maturation of up to 14 days in green fru it significantly increased seed germination in all cultivars. When pep per seeds were allowed to remain in mature red (50 dpa) fruit for vari ous postharvest maturation periods, germination percentages were gener ally significantly greater than in dry storage and mature green (30 dp a) postharvest maturation treatments. Starch concentrations of 'Resist ant Giant No. 4' seeds increased from 10 to 80 mg glucose per 100 g dr y wt. when seeds remained in fruit for 4 weeks after harvest. Dry stor age of seeds following extraction from red fruit did not significantly increase germination, indicating that seed afterripening did not occu r. Short storage periods (7 and 14 days) at low relative humidity (7 a nd 51%) significantly improved seed germination of 'Early Calwonder' a nd 'Resistant Giant No. 4'. Storage for 7-14 days of 'Early Calwonder' and 'Resistant Giant No. 4' seeds at high (97 and 100%) relative humi dities was also beneficial, but at longer periods germination percenta ges of all cultivars dropped. There were few significant differences i n seed dry weight between dry storage and postharvest maturation treat ments. It is possible that in situ priming may have occurred in 30 and 50 dpa seed postharvest maturation treatments. These results suggest that following fruit harvest, pepper seeds should remain in red (50 dp a) fruit for a short postharvest maturation period to achieve maximum seed germination potential.