Issue link: https://read.dmtmag.com/i/314286
www.goodfruit.com GOOD FRUIT GROWER JUNE 2014 35 grow significantly more than the large M.9 group. Unfor- tunately, M.26 seldom grows larger than M.9 in replant sites and can fail to develop a commercially viable can- opy. The large M.9 rootstocks (Nic .29, EMLA, and Pajam 2) have been more reliable in growing an M.26- class can- opy than M.26 in fumigated replant sites. • G.41 has become the most widely available of the replant-tolerant rootstocks. It has demonstrated winter hardiness and woolly apple aphid resistance. It can grow vigorously as a nonbearing tree and calms quickly with cropping. Tree size is about the same as M.9 T337 after six years in the field. There has been concern with graft union strength in the nursery. It appears tree caliper is the strongest correlation at this point with the very larg- est trees showing the very biggest loss. It should be noted that Honeycrisp on M.26 and Pajam 2 have similar issues of weak unions. • G.214 is one of the best-performing replant-tolerant rootstocks. It is very productive. Cold hardiness has not been proven though its siblings have been quite hardy. G.214 is not in commercial rootstock liner production— yet. It is coming. Tree size is comparable to the large M.9 clones. • G.935 is a very reliable replant- tolerant rootstock. It does not have woolly aphid resistance but does have winter hardiness. G.935 grows vigorously as a nonbearing tree and will crop very heavily. Fruit size may be impacted due to overcropping with the first crop. Tree size is about the same as with large M.9 clones. • G.210 has shown excellent replant tolerance in its one planting with only one scion variety in one trial site. Data from a Gala rootstock trial at Wapato, Washington, are very encouraging, and growers should consider this rootstock in trial quantities (around 100 trees) to further evaluate its potential. Eastern data show G.210 as an M.7- size canopy. The Wapato data, with many trees in the plots, strongly show it is not as big as G.30, which is M.26 class in Washington State. Tree size is equivalent to large M.9 in Wapato with Gala as scion. • G.30 is an M.26-class rootstock with excellent replant tolerance. It is difficult to propagate, but some nurseries are expanding production. G.30 is not woolly aphid resistant. • G.890 has been in limited trials in Washington State, but had an excellent demonstration on a tough replant site with sandy soil. G.890 is M26 class in vigor as indi- cated in a sandy soil replant trial and a heavy loam soil, fumigated, in Wapato. It has moderate to high resistance to woolly aphid. • Third-leaf Fuji on Malling 9 rootstock in unfumigated ground at Brewster, Washington. G.214 is one of the best-performing replant-tolerant rootstocks.