Abstract

Potato, an important food and nutrition security can be produced two or more times in a year in Ethiopia. It plays an important role in human diet and a source of income for smallholder farmers. However, its productivity is low owing to limited availability of planting materials and poor tuber sprouting of improved varieties. Lack of quality seed is a major problem affecting expansion of potato production.  The objective of the study is to determine effects of different methods and rates of Gibberellic acid (GA₃) application on dormancy of potato variety, Gera cultivar. The experiment was conducted at Holetta Agricultural Research Center during 2008 to 2009. It consisted of five levels of GA₃ as haulm application, a week prior to destruction and five levels of GA₃ as a dipping treatment immediately after harvest for 24 h. Randomized Complete Block Design with three replications was used. Result revealed GA₃ application affects dormancy and sprouting. Haulm application of GA₃ at 750 and 1000 ppm reduced dormancy period by 24 to 27 days, respectively. Dipping treatments of 40 and 50 ppm reduced dormancy period by 18 to 20 days, respectively. The study indicated that haulm application of GA₃ at 750 or 1000 ppm and dipping treatments of 40 or 50 ppm resulted in early dormancy termination, shoot emergence and increased sprout.

Key words:  Gibberellic acid, dormancy breaking, haulm application, dipping, sprout induction.