EXPLORING ALTERNATIVE BUD BREAK ENHANCING PRODUCT IN 'HAYWARD' AND 'ZESY002' (GOLD3) BY PAINTING APPLICATION

Zespri International Limited has supported the research of alternative bud-break enhancers to hydrogen cyanamide (HC), given the potential for this chemical to be de-registered for use in the kiwifruit industry and the serious risks of production loss from current kiwifruit cultivars should this occur. The bud break and flowering patterns of kiwifruit cultivars ‘Zesy002’ (Gold3) and ‘Hayward’ were studied when treated with HC and alternative bud break enhancer Bluprins^® (BP), through painting at five different application dates before natural bud break (DBNB) during 2013 winter. The 2013 winter chill for the area was 279 h below 7°C compared to the 18 year average of 394 h, and this mild winter chilling condition challenge the effectiveness of the treatments studied. This investigation indicated that Gold3 shows more difficulties maintaining productivity after mild winters with an alternative bud break enhancer. ‘Hayward’ would have serious problems to find an economically sustainable bud break enhancer after a mild winter.