Effects of hydrogen cyanamide on budbreak and flowering in kiwifruit (Actinidia deliciosa'Hayward')

H. G. Mcpherson, A. C. Richardson, W. P. Snelgar, M. B. Currie
2001 New Zealand journal of crop and horticultural science  
Effects of hydrogen cyanamide (HC) application to kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang et A. R. Ferguson 'Hayward') vines were assessed over four seasons in three New Zealand kiwifruit-growing areas. HC advanced the date of budbreak to c. 40 days after application, despite the date of application varying from 33 to 92 days before natural budbreak. For every day that HC advanced budbreak, there was a 0.5-day advance in the date of flowering (r 2 = 0.92). The smaller advance in
more » ... aller advance in flowering resulted from the cooler temperatures experienced between budbreak and flowering in the treated vines. HC applications tended to reduce the spread of budbreak and flowering, with the greatest effect at the warmest sites. H01011 Application of HC usually increased budbreak and the total number of flowers at the warmest two sites, but only slightly reduced their seasonal variation as this was largely the result of the amount of winter chilling vines received. The number of flowers per winter bud produced by untreated vines was reduced by 0.44 per 1°C. The percentage of total flowers that were lateral or side flowers was reduced by HC application from 14 to 4% at the warmest site and 29 to 19% at the coolest site.
doi:10.1080/01140671.2001.9514189 fatcat:4ozivavw5rbb3hohedfpn6uaiy