Multistate Research Activity Accomplishments Reported 2006 (State Summaries, supplement) California: Both the 2001 and 2002 peach rootstock trials have been established in California. The VVA-1 rootstock is the most promising item in both these plantings. It is a thrifty looking dwarf tree with generally good fruit size. For the 2002 trial it had the largest fruit size of all the rootstocks, although it did have some root suckers. In the 2001 trial, fruit size was not as good and the trees seemed a little weak. Thus, there is some concern about its long-term vitality. The 2003 Golden Delicious apple rootstock trial has also been planted in California. This planting has a large number of items that so far look promising. They range from extremely dwarfing to quite vigorous rootstocks. Of particular interest is the apparent resistance to fireblight of many of the rootstocks. In the past 2 years, about half the trees on the standard stocks M26 and M9 have died from this disease. Three trees on PiAu 56-83, one on PiAu 51-11 and one on Bud 62-396 have all died. So far, none of the CG or JM series rootstocks have succumbed to this disease. Colorado: Severe spring frost at or near bloom at the two locations with NC-140 plantings affected fruit production data for 2006. Pumiselect, Cadaman, and SLAP peach rootstocks grew best and tended to have the best fruit production at the included locations, although Pumiselect had poor survival. Final growth data was collected for the 1998 western sweet cherry study in 2006, and opportunity was taken to examine phytoparasitic nematode populations associated with the roots of the sweet cherry rootstocks. This preliminary assessment of the nematode taxa and populations found potential relationships between rootstocks and observed nematode taxa and populations. Further studies on these relationships are planned for 2007. Illinois: Two NC.140 experimental trials are planted at University of Illinois Urbana-Champaign Campus. The oldest trial is the 2002 ÂBuckeye Gala apple on nine rootstocks. Tree size as a function of TCSA showed that Bud-9 Europe and Bud-9 Treco continued to be the smallest, while P.14 is the largest. Yield per tree was adequate with the highest (28.7 Kg) on M.26NAKB and the lowest (12.3 Kg) on B.9Treco. Fruit sizes were largest on M.9nic29 and smallest on Supporter 4. Rootstocks differed in their suckering capacity with Bud-9Erurop producing more than 5 suckers per tree, while M.26NAKB and P.14 did not produce rootsuckers. Fireblight has been a major problem in Illinois in the last three years. The nine rootstocks responded differently to fireblight infection. The most serious tree mortality occurred on M.9 T337 (100), M.26 EMLA (71%), and Supporter 4 (71%). Trees on M.26NAKB suffered 57% loss, trees on M.9 nic29 and M.9 B756 suffered 43% loss, and trees on Bud-9 Treco and Bud-9 Europe suffered only 14% loss. However, trees on P.14 did not suffer any loss to fireblight. Interestingly, Honeycrisp trees on B.9 Treco planted at the same time but not part of the trial were not affected by fireblight. The second and most recent trial was established in the spring of 2006 involves testing the interaction of rootstock genotype and replant disease using ÂMitchell Gala as scion wood grafted on 12 rootstocks. Trees have grown very nicely but it is too early to report any data. Kentucky: All of the NC-140 trials in Kentucky are located at the Research and Education Center in Princeton, KY. One is the 1999 dwarf and semi-dwarf apple plantings. Among the dwarf rootstocks, trees on CG.3041 and CG.4013 have yielded the most fruit, while trees on G.30N have yielded the most fruit among the semi-dwarf trees. Below to normal temperatures throughout the growing season resulted in fair to good color of our Fuji apples. In the 2002 rootstock trial, trees on the M.9 Burg 756 stock have yielded the most fruit over the past three seasons. Trunk cross-sectional area is highest for P.14 followed by M.9 Burg 756 and M.26 NAKBT337. Yield data was taken for the second time from two trials planted in 2003. Trees on PiAu56-83 yielded the most fruit over the past two years, and are the biggest trees in this trial. Trees in the physiology trial were thinned differentially to crop loads of 2, 5, 8, 11, and 14 fruit per square centimeter of trunk cross sectional area. No significant differences were observed among the three rootstocks (G.16, M.9 NAKBT337, and M.26 EMLA)in mortality, cumulative yield, yield in 2006, fruit size (as measured by average weight per fruit), number of flower clusters, number of fruit harvested, crop density, or trunk cross-sectional area. Neither rootstock nor the covariate, crop density, was significant in the analysis of covariance for fruit weight. Maine: Maine has three rootstock plantings. The 2003 NC-140 Golden Delicious rootstock and physiology plantings were maintained according to NC-140 protocol. Trees in the physiology study were not cropped due to insufficient fruit set. A local trial established in 2002 with Honeycrisp on M.26 EMLA and G.16 is being maintained until 2011. Data measurements included trunk circumference, tree height, number of flower clusters and yield. Growth and yield of G.16 trees was generally greater than M.26. Tree survival was similar for both rootstocks. Impacts: Planting superior rootstocks can increase yield and tree survival. Impacts will be measured as changes in the industry and will be documented through grower surveys. Maryland: All current NC-140 peach trials are located on the Eastern Shore of Maryland at the Wye Research and Education Center (WREC) outside of Queenstown. The current trials consist of the 2001 Redtop planting on fourteen different rootstocks, the 2002 Redhaven planting on eight different rootstocks and the 2002 Cresthaven /Lovell physiology study. All trees continue to be maintained using local commercial recommendations for pruning, fertility, pest control and irrigations. All established protocol for data collection have been accomplished and reported to the trial coordinators through the 2006 season. Rootstocks Controller 5 and Controller 9 have exhibited good tolerance to wet soils and some size-controlling attributes. Massachusetts: In the 1998 NC-140 Apple Rootstock Trial in 2006, largest trees with the smallest average fruit size (1999-2006) were on G.16. Cumulative yield per tree (1999-2006) and yield efficiency (1999-2006) were similar for trees on M.9 and M.9 EMLA, but both resulted in less yield per tree and similar yield efficiency than did G.16. In the 1999 NC-140 Dwarf Apple Rootstock Trial (McIntosh), largest trees were on CG.4013 and the smallest were on M.9 NAKBT337, Supporter 1, and Supporter 2. Cumulative yield (2001-06) was greatest from trees on CG.4013, CG.5179, and G.202 and smallest from trees on M.9 NAKBT337, G.16N, and Supporter 1. Cumulative yield efficiency was greatest for trees on Supporter 2 and least for trees on G.16N and M.26 EMLA. Average fruit size (2001-06) was greatest for trees on M.9 NAKBT337 and least for trees on Supporter 2 and Supporter 3. In the 1999 NC-140 Semidwarf Apple Rootstock Trial (McIntosh), largest trees were on G.30N, M.7 EMLA, and Supporter 4 and the smallest were on CG.4814, M.26 EMLA, and CG.7707. Cumulative yield (2001-06) was greatest from trees on G.30N. Cumulative yield efficiency was greatest for trees on CG.4814 and least for those on M.7 EMLA. Average fruit size (2001-06) was unaffected by rootstock. In the 2002 NC-140 Apple Rootstock Trial, the largest trees were on PiAu51-4, and the smallest were on the two B.9 strains. Greatest cumulative (2004-06) yield was harvest from trees on the B.9 strains and M.26 NAKB and the least from those on Supporter 4. The most yield efficient trees were on the B.9 strains. The M.9 strains, B.9 (Treco), and PiAu51-4 resulted in the greatest average (2004-06) fruit size, and M.26 NAKB and Supporter 4 resulted in the smallest. In the 2002, NC-140 Peach Rootstock Trial, trees on Cadaman and Lovell were the largest, and those on VSV-1, Pumiselect, and VVA-1 were the smallest. Greatest cumulative yield (2005-06) and yield efficiency (2005-06) resulted from Cadaman and Lovell and the lowest from Pumiselect and VSV-1. Average fruit size (2005-06) was not affected by rootstock. Pumiselect has experienced the greatest tree loss (50%), followed by Penta (25%), MRS 2/5 (12.5%), and VVA-1 (12.5%). In the 2002 NJ/MA Apple Rootstock Trial (Cameo), trees on G.16 were larger than those on B.9 or M.9 NAKBT337. Trees on G.16 had the greatest cumulative yield (2003-06), and those on B.9 were the most yield efficient. Average fruit size (2003-06) was unaffected by rootstock. Impacts: Approximately 250 acres were planted to dwarfing rootstocks during the last year. All rootstock recommendations are based on the results of this project, and growers rely heavily on those recommendations when selecting the proper scion/rootstock combinations. These rootstocks, will reduce pruning and harvest labor by 50%, increase fruit quality, increase size by 10-20%, and enhance the economic return on this acreage by as much as 50%. Further, smaller trees require 70% less pesticide because of reduced canopy volume. The net effect of the planting in 2006 is to reduce the amount of spray material in total by about 250,000 gallons per year in Massachusetts. The beneficiaries of this yearÂs research are tree-fruit growers and the citizens of the Commonwealth. Michigan: For the ÂMcIntosh apple trials planted in 1999, the G.30 clone appears to be the only semi-dwarfing rootstock performing well in sandy infertile soil of northern Michigan (Traverse City), suggesting commercial promise for this region. CG.5087 warrants further testing due to productivity and vigor. On the better soil of central west Michigan (Clarksville), ÂMcIntosh on the dwarfing CG series 4013, 5202 and 5935 show commercial potential at this time. For the ÂMontmorency tart cherry trial planted in 1998, no rootstock has performed as well as standard mahaleb seedling for trunk-shaker mechanical harvest. However, for alternative mechanical harvest methods that would utilize smaller trees at higher densities, the semi-dwarfing W158 and more dwarfing W72 have higher yield efficiencies than mahaleb. The sweet-tart varieties Balaton and Danube on the vigorous Hungarian mahaleb seedling rootstocks have been yielding better than on standard mahaleb seedling. For mechanically-harvested processing sweet cherries (e.g., Hedelfingen), standard mahaleb and the Hungarian mahaleb rootstocks (Erdi V, CT.2753, and CT.500) have been much more yield efficient than Mazzard, yet fruit quality (size) has been similar. In genetic studies, an efficient adventitious shoot regeneration protocol has been established for successful and stable Agrobacterium-mediated genetic transformation of sour cherry and hybrid cherry rootstock genotypes. Studies of high tunnel sweet cherry production on dwarfing rootstocks have demonstrated yields of 4.0 to 5.4 tons/acre of fruit averaging 12.5 g in weight and 97% 10-Row and larger in size, with projected net (gross value  harvest labor cost) values of $18,650 to $24,500 per acre and reduced needs for chemical pesticide inputs. Minnesota: In the NC140 1999 planting, tree size ranking has not changed significantly. In the dwarf planting, Supporter 1 is the smallest tree and CG.4013 the largest. In the semidwarf planting there are no significant differences among the rootstocks in TCA. Yield for the Cornell-Geneva rootstocks was significantly higher in the dwarf planting than the others under evaluation. Fruit produced on trees grafted onto CG.5202 and CG.4013, on average, produced 28 kg/tree without much of a reduction in fruit size. Fruit produced on trees grafted onto G.30N and CG6210 averaged about 31 kg/tree again without a reduction in fruit size. We established a rootstock trial in the spring of 2003 with a Minnesota breeding selection MN1797, now named SnowSweet (with limited number of trees available for spring 2006 and 2007 planting). Tree growth was excellent during the 2006 growing season even though moisture was limiting during the summer. SnowSweet is a late cultivar for Minnesota with fruit harvested October 12 and has a droopy growth habit. The trend in tree size for Zestar! is for Bud 9 and M.9 trees to be smallest followed by M. 26 and then EMLA. 7. Suckering was evident on almost all EMLA.7 trees. Ranking of tree size after the 2006 growing season is the same as after the 2005 with M.26, Bud. 9 and EMLA 9 being of equal tree size and EMLA 7 being significantly larger. Fruit was harvested August 24th. New Jersey: The two peach plantings were terminated at the end of the 2006 growing season due to virus concerns. The 2001 peach planting (ÂRedhaven cv) had 7 rootstocks with significantly smaller mean trunk crossectional areas than ÂLovell (VVA-1, Jaspi, K146-43, Julior, ÂBaileyÂ, K146-44, and P30-135). Of these 7 smaller rootstocks ÂBailey had significantly higher cumulative yield efficiency than ÂLovell (0.90 vs. 0.63 kg fruit/cm2 TCA) but, the others were not different from ÂLovellÂ. As of 2006 the 2002 peach planting (ÂCresthaven cv) had four rootstocks with significantly smaller mean trunk cross sectional areas than ÂLovell (VSV-1, VVA-1, Penta, MRS 2/5, and Adesoto 101). Cumulative yield efficiency was not significantly different among rootstocks in the 2002 planting. The 1998 NC140 CG-16 Jonagold Rootstock trial compares CG 16 to the standard M9 EMLA. In 2006 there were no significant differences in yield, yield efficiency, or Trunk Cross Sectional Area. The were no cumulative yield and yield efficiency differences for 2000-2006 between these stocks. This trial will be terminated after this growing season. In the New Jersey/UMASS G16 Cameo NC140 Rootstock Trial, B9 was the smallest stock by TCSA, G16 the largest. B9 was the most yield efficient stock in 2006 and had the largest cumulative yield efficiency (2003-2006). B9 and M9337 had significantly higher average fruit weight over G16 in 2006. 2002-NC-140 Gala Apple Rootstock Trial consists of 11 rootstocks. Tree growth was excellent in 2006. There was no significant difference in average fruit size, yield or yield efficiency between stocks. Rootstocks affected TCSA, cumulative yield and cumulative yield efficiency at the end of the 5th growing season. The largest trees at the end of 2006 were PiAu51-4 and P. 14 and the smallest trees were B.9Europe followed B.9Treco. B.9Europe and B.9 Treco stocks had the highest cumulative yield and efficiency. There were no significant differences in average fruit size. 2003 NC-140 Apple Physiology Trial- This year was our first opportunity to evaluate the effect of crop load and its interaction with rootstock in this planting. Trees had adequate bloom and fruit set to establish nearly the full complement of crop loads requested by the protocol. There was a significant interaction effect of crop load and rootstock on average fruit weight (P=0.0040). Fruit weight decreased linearly with increasing crop load on the G16 and M26 but not on R337 (Fig 1). There was also a significant interaction effect of crop load and rootstock on TCA growth from 2005 to 2006 (P=0.0019). TCA growth decreased linearly with increasing crop load on G16 and R337 but not on M26. 2006 NC140 Apple Replant Trial NJ and MA Cooperating- Twelve rootstocks from the Cornell breeding program including standard stocks were utilized. At the end of the 2006 growing season G.4210 was the smallest stock and G.5935 was the largest. G.4210 had the largest increase in circumference from spring to fall in 2006. B.9 had the smallest increase in circumference. New York: Several apple rootstock trials showed G.41 was the most yield efficient dwarf stock we are evaluating. G.16 was also highly efficient. A field trial conducted jointly by Cornell University and USDA-ARS showed that almost all of the CG rootstocks showed no rootstock death to fire blight when the scion was inoculated. Exceptions were G.11, G.65, G.935, CG.4288 CG.6006 and CG.6210 which each had a low percentage of trees infected. B.9 also had a low level of trees infected in this trial. Low levels of infection were also shown for P.14 P.22, PiAU56-83, Vineland 3 and M7. New rootstocks from Japan (JM series) showed no infections except JM.2. The Vineland series of rootstocks showed no infection except Vineland 3. All of the Malling stocks except M.7 showed a high level of infection as did Ottawa3, and Supporter 4. A pruning study overlaid on the 1998 sweet cherry rootstock trial showed a trend toward larger fruit size from spur extinction pruning or stubbing back pruning even of dwarfing stocks. Nevertheless the dwarfing stocks continued to produce smaller fruit size. Analysis of covariance showed that the difference in fruit size was largely the result of high crop loads with the dwarfing stocks. Peach experiments showed that Controller 5 and Krymsk-1 (VVA-1) survived much better in NY state than any other stocks. These have high potential as improved peach rootstocks for northern growing areas. NY Outreach Activities A grower field day was held in July to highlight high density sweet cherry orchards on several dwarfing rootstocks which stimulated grower interest to expand sweet cherry acreage in NY State. A grower field day was held in Northern NY to highlight high density apple orchards on various dwarfing rootstocks to improve the productivity and profitability of new apple orchards in the Northern production areas of the state. North Carolina: North Carolina has four of the NC-140 cooperative apple plantings. The trials that are currently under investigation in North Carolina are the 1998 gala planting, both the 1999 fuji dwarf and semi-dwarf plantings and the 2006 apple replant trial. Growing conditions in 2006 were ideal with adequate rainfall during the summer and no significant frost/freeze conditions in the spring during bloom. In the 1998 gala planting the trunk cross-sectional area (TCSA) of trees on G.16, M.9 EMLA and M.9NAKBT337 were not significantly different, however trees on G.16 were numerically larger and those on M.9NAKBT337 were the smallest . Trees on G.16 had the greatest cumulative yield which was significantly greater than that of trees on M.9EMLA which had the least. In the dwarf fuji planting, trees on CG.4013 had the largest TCSA and trees on M.9 NAKBT337, Supporter1, 2, and 3 had the smallest. Trees on CG.5935 had the greatest cumulative yield and trees on Supporter 1 the lowest. In the semi-dwarf planting, there were no significant differences in TCSA, although trees on CG. 6210 were the largest and those on CG.4814 the smallest. Cumulative yield was greatest for trees on CG.6210 followed by G.30T and CG. 7707 and the lowest yield was for trees on M.7 EMLA and M.26EMLA . Following the tropical storm damage received in 2004, several rootstocks of interest that may have brittle or shallower roots are CG.5179, Supp.4, CG. 7707, G.30N and G.30T. Data from the 2006 apple replant study will not be collected until mid-winter 2007. The information generated in this project is given at grower meetings and orchard tours are held in the plantings to help educate our clientele in the southeast about apple rootstocks. Nova Scotia: Season and Crop: The winter was considered generally mild. The lowest temperature was on February 12 at -19.4oC. The season started very dry and ten days to two weeks earlier than usual. McIntosh full bloom was May 24th which was almost two weeks earlier than usual. Immediately following the bloom period and during bloom for the late varieties, cloudy overcast wet weather moved in and persisted for about two weeks. The lack of sunshine, we believe, increased the efficiency of thinners and confirms earlier work by Ross Byers. Cortland appeared to be especially sensitive, and there were reports of over thinning with Sevin. All this led us to predict a lower crop than usual, however fruit size was larger than normal, and the late varieties preformed well, so there was only a slight reduction in the regionÂs crop. Status of the Current and Previous Trials at Kentville, Nova Scotia and Bouctouche, New Brunswick: The following trials are currently in place at Kentville: the 2006 Replant Study; the 2005 Pyro-Dwarf Pear Rootstock Trial; the 1999 Cornell Geneva dwarf and semi-dwarf rootstock planting; and the 1998 Cornell/Geneva G. 16 and G. 41 mini planting The 2006 replant trial was not planted until very late so growth has been minimal this year. This was planted by David Baldwin under the direction of dr. Privé who had planed to combine the Bouctouche and Kentville trials. Since that time, he has accepted a acting position in administration and will not be available for the next six months, it is not known how this will impact on the long term plans. In the mean time, C. Embree is continuing to supervise the research. For the 1998 JonaGold trial, the rootstock G.16 is 27% larger than M.9, G.41 is slightly smaller than G.16. In 2006 fruit size was smaller on M.9. The 1984, 1989, and 1992 plantings are still in place, but are being used for other studies. Pennsylvania: Sudden cold temperatures in early December 2005 killed all but two of the Redhaven/ MRS 2/5 trees in the 2002 peach trial. This suggests that trees on MRS 2/5 may harden off more slowly than is desired. Tree mortality is high for G.41 in the 1998 apple planting. Our preliminary diagnosis for the tree loss is graft union necrosis (ToRSV). G.16 and M.9 have 100% survival in this planting, and trees on these two stocks are very comparable in growth and performance. Further diagnostic study is planned to confirm the preliminary conclusion. Tree mortality is very high for all three Supporter rootstocks in the 1999 dwarf Fuji planting in Biglerville. Fuji trees on Supporter rootstocks at Rock Springs are also growing and performing poorly, while McIntosh trees on Supporter rootstocks have growth and productivity similar the other rootstocks in the trial. The 2006 replant X rootstock planting grew well, although initial tree quality, caliper, and number of feathers were highly variable. Data collection for 2006 is underway for all plantings. Research results will form the basis for making rootstock recommendations to Mid-Atlantic fruit growers. South Carolina: In the 2001 peach trial, ÂRedtop on BH-4, K146-43, and K146-44 rootstocks had 100% survival after 6 years in the orchard. SLAP and SC-17 continued to be the most vigorous rootstocks. No rootstock produced fruit significantly larger than Lovell. SC-17 and Bailey have been the most productive rootstocks over the last 4 years, with cumulative yields ~270 kg/tree. Bailey, Hiawatha, K146-43, VVA-1, and Lovell have the highest cumulative yield efficiencies. Julior, Jaspi, and VVA-1 continue to produce trees with low vigor and fruit yields. There was a 3-day range in bloom date and a 4.5-day range in maturity date. In the 2002 peach trial, ÂRedhaven on Lovell and K146-43 have 100% survival after 5 years in the orchard. Cadaman and Lovell continue to be the most vigorous rootstocks, and Mr.S. 2/5, VSV-1, and VSA-1 continue to be the least vigorous. Fruit of trees on VVA-1, Cadaman, and Lovell were largest, and fruit of trees on Mr.S. 2/5 were smallest. Cadaman and Lovell had the highest fruit yields in 2006, and were the most productive rootstocks over the last 3 years, with cumulative fruit yields >150 kg/tree. Adesoto 101, Mr.S. 2/5, VSV-1, and VVA-1 had the lowest yields. Low-yielding rootstocks ( 20 kg/tree), and highest cumulative yields (> 45 kg/tree). GI 195-20 had the highest yield efficiency in 2006 and highest cumulative yield efficiency. Mahaleb and Mazzard continue to be the least yield efficient rootstocks. In the 1999 Fuji dwarf apple trial, trees on Geneva 16N rootstocks continued to be the most vigorous, and trees on Supporter #3 rootstocks were the least vigorous. Fruit size was largest with Geneva 16N and M.9T337 rootstocks and smallest with Supporter #2 and Supporter #3. There were no significant differences in fruit yield in 2006. CG.179, Supporter #2, and Supporter #3 rootstocks had the highest yield efficiency in 2006 and also over the last 6 years. In the 1999 Fuji semi-dwarf apple trial, M.26 rootstocks continued to be the most vigorous. There were no significant differences in fruit size, total fruit yield, or cumulative fruit yield. Yield efficiencies were highest with CG.814 in 2006. Cumulative yield efficiency was much higher with CG.814 and Supporter #4 than with M.26.

"myk: Since you know more about apple rootstocks than the Washington state apple industry why don't you enlighten us further." I don't and never claimed to. I have just NEVER heard that (until now) or experienced that with M111 (only have one bearing but have known and heard of many). When I was researching G11 before I bought it last year I recall seeing it with what you posted saying about it plus that it isn't as bad about replant as the other Genevas (at the time). I haven't looked into G41 and going by memory on G11, crown rot for G11 vs wooly aphid for G41 (G11 is moderate for wooly aphid). Unless you forgot to list something I can't say that either of those resistances would make either "best" for everyone. Fireblight, replant, hardy, precocious and high yielding (possibly overly so) apply to both. I'm trying to talk my niece into a real orchard and am trying to learn about rootstock so I can be ready with the "best" when she gives in. So is there something else that makes G41 the best or is it simply the newest? Since you reminded me, what are spines in the stoolbed? Here's something from Cummins about the Genevas, http://www.cumminsnursery.com/aboutroot.htm They compare G41 to M9 and G11 to M26. But they also say G11 isn't as resistant to FB as other Genevas.

The following information has been "cut and copied" out of the planting guide for St Lawrence Nurseries out of Potsdam, NY. They also have a picture of how to do this but it didn't copy: PLANTING YOUR TREE How deeply to set fruit trees When planting standard size grafted fruit trees, (like ours,) it is best to encourage them to become at least partially âÂÂself-rooted,â that is, to promote rooting above the graft union. To accomplish this, you must plant grafted apples, pears, plums and cherry trees an inch or two deeper than they were in the nursery, with the graft union (near the root collar) below the ground. (See photo below.) The graft is sometimes hard for an unpracticed eye to locate, but will look like a healed diagonal scar on the stem that resembles a "Z." What was formerly the aboveground portion (the scion) will sprout new roots, and these roots will be from the actual cultivar*, rather than from the rootstock onto which it was grafted. If the tree is ever damaged and then sends up rootsprouts from the base, these will be growing from above the graft rather than from the rootstock, and will make a new tree of the same variety. Use this recommendation only if you are planting a standard size tree, since planting a dwarf fruit tree in this manner will negate the dwarfing influence of the rootstock. (See Apples.) Our Bali cherry and Northrup mulberry are grown from tissue culture and do not have a graft union. (end of cut and copy) St. Lawrence Nurseries grows, grafts, and sells over 150 varieties of apple trees that are grafted onto Antonovka root stock. Their target market is the very cold zones. I'm sure that they graft way more apple trees every year than any University does. With all of the variables & differences: root stocks, skill of the grafter, healing time, climate, and soil make up: it's difficult to talk in terms of absolutes. Having 3 trees die shouldn't condemn a practice for all situations.

Jayco, from my limited experience, some of the Geneva rootstock may do well for you. Last year about this time I planted 18 varieties in my Georgia clay with no amendments on G-11 and G-16 rootstock. The trees I got from Cummins were in the 3 to 4 foot range at planting and grew like wildfire the 1st year. Almost all of them are now 7 to 8 foot and pretty well branched. The 2 varieties I have on M-7 do not seem to like the clay as well and are growing at a slower pace. Chris.