Effects of hormone and cold treatments on dormancy breaking of Jerusalem artichoke (Helianthus tuberosus L.) tubers

Abstract

The objective of this research was to determine the effects of gibberellic acid, cytokinin and ethylene and chilling at 5 °C for 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 weeks on germination of Jerusalem artichoke (Helianthus tuberosus L.) tubers. Gibberellic acid, cytokinin, ethylene and a blank control were assigned as factor A, and four Jerusalem artichoke varieties including JA 89, HEL 65, CN52867 and hybrid variety, 50-4 were assigned as factor B. A 4×10 factorial experiment in a randomized complete block arrangement of the treatments with four replications was laid out for the chilling treatment. Data were recorded for germination percentage after 7 days of germination for hormone treatment and for 7 days of germination for chilling treatment. A significant difference of three plant hormones was found for Jerusalem artichoke tuber germination. Gibberellic acid was effective for breaking dormancy of four Jerusalem artichoke varieties, influencing the highest tuber germination percentage from both times of evaluation. For breaking tuber dormancy by chilling, highly significant different periods of chilling were found for a percentage of tuber germination. Ten weeks of chilling in 5 °C showed the highest germination, 96.3 %. JA 89 and 50-4 exhibited high germination in both breaking dormancy methods