The Geneva Series
In the late 1960s, a "double-whammy" hit many blocks of apples on the clonal rootstocks just then being seriously planted in New York orchards. Trees on Malling-Merton 106 were going out with what was diagnosed as Phytophthora collar rot, and whole blocks on the dwarfing Malling 9 were killed by fire blight.
Dad began his rootstock breeding program in 1968, aiming at producing a repertoire of rootstocks that could survive under fire blight and Phytophthora pressure, thrive in our climate (so different from that of southeast England where the Malling and Malling-Merton stocks had originated), and provide outstanding orchard performance. He used Robusta 5 and Novole as primary sources of resistance to fire blight and relied on Malling 9 and M.27 for Phytophthora resistance. In the early 70s, pathologist Herb Alwinckle joined the team.
Over the years, they produced well over 300,000 hybrid seeds, emasculating and pollinating perhaps 100,000 flowers. Our whole family was involved in that hybridization. To have a longer breeding season, we went as far south as National Arboretum in Washington and north into Quebec. All those seedlings were inoculated with Phytophthora in the greenhouse, then with fire blight bacteria; some were tested with woolly apple aphids. Then outside for testing in the stoolbed.
Based on stoolbed behaviour, many hundreds of the seedlings were grafted with test varieties, all virus-free: Northern Spy, Delicious, McIntosh mostly. Test blocks were set out across the country, from Maine to Washington, with a 20-acre planting at USDA research station at Kearneysville. After Dad and Herb retired, Terence Robinson and Gennaro Fazio have continued evaluating the selections.
SELECTIONS FROM THE GENEVA BREEDING PROGRAM:
GENEVA 65® "Little Beauty" My mother's favorite. The first introduction from the breeding program at Geneva, NY under the direction of Dr. James N. Cummins and Dr. Herb Aldwinckle. Very dwarfing, between M.9 and M.27. G.65 is precocious, very productive, resistant to crown rot and almost immune to fire blight. (In the nursery, G.65 is resistant to scab and mildew, too). Trees on G.65 are sturdy, well-anchored, thrifty little trees but they do require irrigation. Some suckering; nearly no burrknots. Extremely difficult to propagate, so much so that we have never been able to get it into commerce. Macs on Geneva 65 survived the severe winters in Quebec. Probably most suitable as patio plants and for the intense backyard hobbyist.
GENEVA 16® (G.16®) From the Cornell-Geneva breeding program; Dad’s favorite of all his “children”. Ottawa 3 x Malus floribunda. Resistant to crown rot and fire blight. In the nursery, immune to apple scab, susceptible to powdery mildew. Very susceptible to woolly apple still not aphids. Vigor slightly more than Malling 9; tree grows very strongly in the nursery and in the first couple of years in the orchard. Suckers and burrknots are very rare. Not nearly as brittle as M.9; much better anchorage. However, we have seen some union breakage in young trees just coming into bearing, especially under the brittle varieties Gala and Honeycrisp. We strongly suggest staking these varieties. Some customer feedback suggests that trees on G.16 may survive drought unusualy well. Sensitive to the common latent viruses; only virus-free scionwood may be used. Trees on G.16 bear early and are very productive. Especially well suited to Mutsu and other triploids.
GENEVA 11® My favorite! From Cornell-at-Geneva. A Malling 26 x Robusta 5 hybrid. Very precocious, very productive, good resistance to both fire blight and collar rot. Very few burrknots. Woollies find it much less attractive than M.26 or M.9 At my brother’s orchard near Ithaca, NY, Mutsu on G.11 are the most handsome trees in the orchard. In the Liberty test plantings at Geneva, trees on G.11 have given excellent performance. Very little suckering.
GENEVA 30® From Cornell-at-Geneva. A major challenger for M.7, G.30 is similar to M.7 in dwarfing but is better anchored, more precocious and much more productive, and much less prone to burrknots. A terrible nursery subject -- fairly difficult to root; many spines. In some test plantings subjected to unusually high winds, there has been union breakage of Gala trees on G.30. We now recommend that most varieties on G.30 be given support, especially during the early fruiting years; we have seen no breakage after five years in the orchard;. Resistant to crown rot and fire blight; apparently tolerant of replant disease.
GENEVA 41 (G.41) A little more dwarfing than Malling 9. From the Ottawa 3 x Robusta 5 cross. Selected for resistance to crown rot, woolly aphids and fire blight. Outstanding production. We think G.41 is the best replacement for Malling 9 in high density plantings;
GENEVA 935 (G.935) Dwarfing between M.26 and M.7. From the Ottawa 3 x Robusta 5 cross. Fantastic productivity. Resistant to crown rot and fire blight; tolerant of replant disease.
GENEVA 202 (G.202) First Geneva rootstock resistant to woolly apple aphids, as well as crown rot and fire blight. Already in heavy production in New Zealand. Dwarfing similar to M.26 and G.11. Not as productive as G.11, but probably a better choice in the South, where WAA is a problem.
Malling 9 Produces a fully dwarfed tree with good fruit size and color. Precocious and very productive. Requires a permanent support system. Irrigation is very helpful. Resistant to crown rot. Susceptible to nematodes, woolly apple aphid, and fire blight. Because fire blight is becoming so critical throughout our area, we are no longer working with M.9.
OTTAWA 3 (O.3) A winter-hardy dwarfing stock from the Canadian rootstock breeding program-- Malling 9 x Robin Crab. Just a little more vigorous than M.9. Resistant to collar rot, but susceptible to fire blight and woolly aphids. Difficult to root in the stoolbed. In the orchard, the first year or two growth is very slow. No burrknots.
M.7 EMLA The old workhorse of the apple industry. Usually free standing, although sometimes anchorage can be a problem. Half of standard-sized tree. Moderately resistant to crown rot and to fire blight. Suckering can be a problem. Trees on M.7 are quite cold hardy. The Malling 7 root systems tends to be vertically oriented; if the roots hit an inpenetrable clay pan at 12 to 18 inches, root growth usually stops and the tree "runts out".
MALLING-MERTON 106 Still the best of the more vigorous rootstocks -- precocious and productive, well-anchored. But MM.106 is very susceptible to crown rot and almost uniquely sensitive to Tomato Ringspot Virus. We do especially like MM.106 under spur-type trees and under a dwarfing interstock such as Budagovsky 9 or Malling 9. A great rootstock in the right spot, but a poor choice for some sites.
MALLING-MERTON 111 Close to 80% of full standard vigor, MM.111 is more tolerant of difficult soil conditions than the other English rootstocks. Not precocious -- which is one reason we don't put Northern Spy on it!! Quite prone to burrknots. We like to use MM.111 under spur-type varieties and under interstocks.
BUDAVGOSKY 9 (Red-Leaved Paradise) (Bud.9) Same level of dwarfing as Malling 9, but about 5 degrees more winter hardy. In some tests, Bud.9 has not been quite as productive as Malling 9. In two recent trials, Bud.9 has been much more tolerant of fire blight than M.9 and we are using Bud.9 under fire-blight susceptible varieties. Not quite so brittle as Malling 9, but staking is still strongly advised.
P.2 A Malling 9 x Common Antonovka hybrid from the great Polish rootstock breeding program at Skierniewice. (No, the "P" doesn't stand for "Polish" or "Poland", but for the Polish word for rootstock.) Slightly less vigorous than Malling 26. Almost as winter hardy as Antonovka. Resistant to collar rot; susceptible to fire blight and woollies. Anchorage similar to M.26. Very productive.
Malling 26 Very productive dwarf tree -- but south of Pennsylvania, maybe more vigorous than expected. Better anchored than M.9, but at least temporary support is still recommended. M.26 is very, very susceptible to fire blight, burrknots, woolly apple aphids and crown rot. However, if M.26 is planted on a well drained (not droughty) soil, trees can give outstanding production.
BUDAVGOSKY 118 (Bud.118) About the same vigor as MM.111, but as winter-hardy as Antonovka. Burrknots and suckers are rare. Productive; well-anchored. Red leaves, red wood, red blossoms, red fruit.
ANTONOVKA This seedling rootstock is grown from seeds imported from Poland. Full "standard" vigor. Very winter-hardy. Has been our major rootstock for conservation plantings.
NOVOLE An introduction from the Geneva rootstock breeding program, Novole has a "non-preference" type of resistance to meadow voles and pine voles ("orchard mice"). Very vigorous; best used as a root-and-trunk stock, with a dwarfing interstem interposed about 16 inches above the ground. Virus-sensitive; all components must be virus-free. Resistant to fire blight and collar rot. Available sometime in the future as a rootstock
Pyrus betulifolia Standard vigor. Reimer's strain of fire blight-tolerant seedlings. Reported to enhance fruit size on Asian pears.
OHXF 97 These OHXF stocks originated from the Old Home x Farmingdale cross; both parents are very resistant to fire blight. OHXF 97 is full standard vigor; fire blight resistant. More productive than seedling.
OHXF 87 Outstanding semi-vigorous clonal stock. Excellent anchorage. Tolerant of soil diseases. Very resistant to fire blight. Tolerant of low temperatures. Induces early, heavy production.
OHxF 333 Somewhat more dwarfing than OHxF 87, with similar resistances. Some reports that fruit size is smaller, but this may be due to excessively heavy fruit set
QUINCE EM A Fully dwarfing rootstock, with very heavy production. Fruit ripens 3 to 5 days earlier than on seedling stocks. Quince A is not as winter hardy as our other pear stocks. Fire blight susceptible.