Evaluation of various methods to break dormancy of potato (Solanum tuberosum L. 'Granola') minitubers

摘要

Different postharvest treatments were used to evaluate dormancy break in 'Granola' potato [Solanum tuberosum L.) minitubers. Treatments included ethephon (5,000 and 10,000 uL L1), modified atmosphere packaging (MAP) using 0.002 mm polyethylene bags (PEB), calcium carbide (CaC2,3 and 5 g kg-1) plus MAP, gibberellic acid (GA3, 1 and 5 uL L1) and 1-methylcyclopropene (1-MCP, 1 and 10 uL L1, 48 h). As early as 3 weeks or at opening of the PEB, minitubers treated with 3 g kg1 CaC2 and MAP had the highestsprouting percentage of 50%. This trend was consistent up to nine weeks of storage wherein 3 g kg1 CaC2 and MAP treatments resulted in highest sprouting percentage (71 and 72%, respectively). Treatment of 3 g kg1 CaC2 gave the highest weight loss (11%) at 12 weeks. Sprouting resulting from the different treatments ranged from 60 to 77% at 12 weeks, indicating long dormancy in 'Granola' minitubers. The ethephon and 5 uL L1 GA3 treatments exhibited more than 50% sprouting at 9 weeks after treatment (WAT),but not the control, 1 ul L1 GA3 and 1-MCP. Dormancy break with the use of CaC2 (3 g kg *) resulted in most sprouts per minituber (2.9) and longest apical sprouts (3.5 mm) relative to the control (0.90 and 1.4 mm, respectively). However, CaC2 and MAP treatments resulted in greater minituber decay at four weeks.