Chemical methods on breaking dormancy of low chill nectarines: preliminary evaluations in subtropical Queensland

Abstract

Three chemicals, Alzodef (49% hydrogen cyanamide) at 20 mL/L, thiourea at 10 g/L and potassium nitrate at 40 g/L were tested either alone or in combination for their effects on breaking dormancy in the low chill nectarine cultivar Sunred in subtropical Queensland. Compared with potassium nitrate and thiourea, Alzodef proved more effective in breaking dormancy and advancing budbreak and fruit maturity. However, Alzodef reduced both fruit set and final yield. Yield losses were greater when application of Alzodef was delayed from 5 weeks to 1 week before natural budbreak.