Preliminary Evaluation of Supported and Free Standing 'Honeycrisp' Trees on 24 Apple Rootstocks

Trees of 'Honeycrisp' apple (Malus domestica Borkh.) grafted on 24 rootstocks were planted at 1000 trees/ha in 2004 at Bouctouche, NB, Canada (46 degrees 26'N) and grown with and without a three-wire trellis support system. The rootstocks included selections from the M, MM, Budagovsky, Geneva (R), KSC, and V series as well as Alnarp 2, Maruba Kaido, Novole, Ottawa 8, Polish 18 and Yltoinen Piikkio. Trunk cross-sectional area (TCA) was measured yearly while reproductive variables (flowering, fruit size, total and marketable yield) were monitored in 2006 and 2007. The fastest growing trees were on Geneva (R) (G) 30, KSC.6 and KSC.7 and the slowest on Novole, CG.054 and KSC.28. The best overall precocity and yields were from trees on G.30. Other rootstocks showing promise were CG.008, V.1, V.7, M.26Emla and O.8. Very few differences in TCA were noted between supported and non-supported rootstocks. However, supporting trees had a positive impact on precocity which resulted in a two-fold increase in their total yields. High winds in 2007 caused some breakage with most damage occurring to the free-standing trees. The breakage was most prevalent in some rootstocks, notably G.30, CG.090 and V.7.