ROOTSTOCK INFLUENCE ON KIWIFRUIT VINE PERFORMANCE

The influence of nine different rootstocks on the growth and cropping of four selections of 'Hayward' kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson) budwood 4 and 5 years after grafting is reported. Principal component (PC) analysis was an effective technique for ordering the rootstocks on the basis of their overall merit. Growing vines on their own roots tended to produce high yields in both the 1989 and 1990 seasons, when compared with seedling rootstocks. This response was associated with low total soluble solids content (degrees-Brix), high budburst, and high vigour leading to a large trunk diameter. Plants on three rootstocks achieved a higher field performance associated with a heavy yield of large-sized fruit, and low budburst, on vines of large trunk diameter. The field performance of 'Hayward' vines on their own roots, topworked onto a male rootstock, or topworked onto one female clonal rootstock tended to be higher (P less-than-or-equal-to 0.06) than 'Hayward' on 'Bruno' seedlings. Scions on one other rootstock were characterised by weaker and less productive vines in both seasons. Perfomiance of the rootstocks is continuing to be monitored as the vines mature.