ROOTSTOCK AND INTERSTEM EFFECTS ON POME- AND STONE-FRUIT TREES

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
205	1110	1060	80%
205	1112	1060	20%

Progress 10/01/02 to 09/30/07

Outputs
OUTPUTS: 2006 was the 6th fruiting yr for most of the rootstocks with tremendous variability in fruit yield/tree. Sixteen of 17 rootstocks in this trial exhibited greater productivity compared to Mazzard. Many trees reached full production in their 9th season. Fr W53, by far the most size-controlling of the rootstocks, had low yields due to limited canopy size and is too dwarfing to produce commercially acceptable yields. Low yields are inherent in P-50 and Mazzard due to poor floral bud induction. Lack of yield from Mazzard-rooted trees remains a significant concern and greatest drawback. Cumulative yield data reveal overall lack of productivity on Mazzard. Precocity and productivity of the Gisela series is again apparent. Early yields were 3- to 6-fold greater than Mazzard. Bing productivity on Mazzard increased every yr, suggesting that after 9 yrs these trees have not yet reached full production. Vigor varied among rootstocks more than 5-fold. Mazzard is the most vigorous and W53 the least. Low-yielding, vigorous rootstocks like Mazzard and P-50 will not provide growers the early returns on investment or size control necessary to improve labor efficiency, and are not recommended for Bing. Several rootstocks exhibit moderate to high yield and vigor control which may be desirable and appropriate for high density, more efficient plantings. Our analyses suggest almost every rootstock is an improvement upon Mazzard. In a slightly-dwarfing category, Gisela 6 is the most promising rootstock and in a semi-dwarfing category Gisela 5 is the most promising. Fruit quality overall was good on most rootstocks. No clear relationship between fruit yield or yield efficiency and fruit soluble solids or firmness was recorded. In 2005 and 2006 we documented a significant variation in harvest date based on fruit skin color. Average harvest date for all rootstocks was June 24 and highlights the need to consider rootstock when planning new orchards for a particular harvest season. Rootstock also affected date of 1st and full bloom. Mazzard-rooted trees were the last to achieve full bloom. In 2001 we planted an orchard of 16 scion varieties on both PiKu 1 and PiKu 3 rootstocks. 2006 was this orchard's third year of fruiting for most varieties. On PiKu 3, Bing and Selah were the least productive, though, due to poor fruit set overall, yields were low throughout the orchard. BlackGold/PiKu1 was the most productive combination. Fruit firmness and soluble solids were about 6% higher on PiKu 1. Tree mortality was similar for both rootstocks. Particularly poor combinations appear to be Attika/PiKu 3, Glacier on both PiKus , and Lapins/PiKu 1. Fruit quality among scion varieties varied considerably in this 3rd yr of production. Overall, productivity is low on these rootstocks, compared to the Gisela series. There was no research activity in 2007 and this project will be terminated. PARTICIPANTS: M.D. Whiting, Washington State University TARGET AUDIENCES: Cherry breeders and producers

Impacts
Previous research has identified several advantageous rootstock selections. Summit, Tieton, Attika, Black Gold, Rainier, Regina, Selah, Sweetheart, and Skeena were among the largest fruit. High quality fruit can be grown on precocious, dwarfing rootstocks. Rootstocks Gisela 5 and Gisela 6 are recommended for Bing. The commercial adoption of these new rootstocks will improve labor efficiency and production economics significantly. Rootstocks identified as having potential from this research now account for approximately 50% of all rootstocks sold in the Pacific Northwest. Rootstock (significantly) altered Bing fruit maturity (ca. 5 days) and bloom timing (4 days. Fruit yield and fruit maturity was unrelated to tree vigor, and tree vigor was related negatively to bloom date (i.e., smaller trees bloom earlier than large trees). Gisela 6 induced the greatest cumulative yield (1998-2006) of fruit 10.5-row and larger (160 kg/tree), Mazzard induced the third least among rootstocks (49.6 kg/tree). Mazzard had the lowest yield in 2006 but the highest quality fruit. The worst quality fruit was harvested from Gisela 209/1 and Edabriz. No rootstock out-performs Gisela 5 or Gisela 6 in the vigorous, semi-dwarfing categories. PiKu 1 is less vigorous and more precocious than PiKu 3

Publications

No publications reported this period

Progress 01/01/06 to 12/31/06

Outputs
2006 was the sixth fruiting year for most of the rootstocks with tremendous variability in fruit yield per tree. Clearly, rootstock has a significant effect on Bing precocity and productivity. Sixteen of the 17 rootstocks in this trial exhibited greater productivity compared to Mazzard. Many trees reached full production in this ninth season; most notably the Gisela series. Fr W53, by far the most size-controlling of the rootstocks, had low yields due to limited canopy size. We conclude that, even at a high tree density, this rootstock is too dwarfing to produce commercially acceptable yields. Low yields are inherent in P-50 and Mazzard due to poor floral bud induction. Lack of yield from Mazzard-rooted trees remains a significant concern and its greatest drawback. Cumulative yield data reveal overall lack of productivity on Mazzard. Mazzard was the 3rd least productive rootstock of all 17. Precocity and productivity of the Gisela series is again apparent. Early yields were 3- to 6-fold greater than Mazzard. Bing productivity on Mazzard has increased every year, suggesting that after 9 years these trees have not yet reached full production. Our data suggest that Gisela-rooted Bing trees reached full production in their 4th and 5th leaf. Vigor varied among rootstocks by more than 5-fold. Mazzard is the most vigorous and W 53 the least. Low-yielding, vigorous rootstocks like Mazzard and P-50 will not provide growers the early returns on investment or size control necessary to improve labor efficiency, and are not recommended for Bing. However, these rootstocks may be appropriate for very productive and precocious varieties like Chelan and Sweetheart, especially when grown in poor soils. Several rootstocks exhibit moderate to high yield and vigor control which may be desirable and appropriate for high density, more efficient plantings. In this regard, our analyses suggest almost every rootstock is an improvement upon Mazzard. In a slightly-dwarfing category, Gisela 6 is the most promising rootstock. In a semi-dwarfing category the most promising rootstock is Gisela 5. Fruit quality overall was good on most rootstocks. Fruit firmness was low likely due to unseasonably warm temps before harvest. We recorded no clear relationship between fruit yield or yield efficiency and fruit soluble solids or firmness. However, there was a clear negative relationship between yield efficiency and fruit weight. In addition, % fruit 10.5-row and larger was related closely and negatively to tree yield efficiency. There was a positive relationship between tree yield efficiency and % 11- and 12-row fruit. Actual yield from Mazzard-rooted trees was considerably less, suggesting these trees were very much under-cropped in relation to the capacity of the canopy to support fruit growth. In 2005 and 2006 we documented a significant variation in harvest date based on fruit skin color. Average harvest date for all rootstocks was 24 June. This result highlights the need to consider rootstock when planning new orchards for a particular harvest season. Rootstock also affected the date of first and full bloom. Mazzard-rooted trees were the last to achieve full bloom.

Impacts
1. high quality fruit can be grown on precocious, dwarfing rootstocks. 2. Gisela 5 and Gisela 6 are recommended for Bing. 3. rootstock affected scion vigor, yield, and fruit quality. 4. rootstock altered Bing fruit maturity (ca. 5 days) and bloom timing (4 days) significantly. 5. fruit yield was unrelated to tree vigor. 6. fruit maturity was unrelated to tree vigor. 7. tree vigor was related negatively to bloom date (i.e., smaller trees bloom earlier than large trees. 8. the Gisela series is very precocious/productive. 9. Gisela 6 induced the greatest cumulative yield (1998-2006) of fruit 10.5-row and larger (160 kg/tree), Mazzard induced the third least among rootstocks (49.6 kg/tree. 10. Mazzard had the lowest yield in 2006 but the highest quality fruit. 11.the worst quality fruit was harvested from Gisela 209/1 and Edabriz. 12. no rootstock out-performs Gisela 5 or Gisela 6 in the vigorous, semi-dwarfing categories. 13.PiKu 1 is less vigorous and more precocious than PiKu 3. 14.novel crop load management strategies will need to be developed to grow high quality sweet cherries on precocious and dwarfing rootstocks.

Publications

No publications reported this period

Progress 01/01/05 to 12/31/05

Outputs
In the 1999 Fuji dwarf rootstock trial, tree size (TCA) was smallest for M.9 (industry standard), Supporter 1, 2 and 3, and M.26 (industry standard). The rootstocks that produced trees significantly larger than M.9 were CG.5935, G.16N and G.16T. Rootstocks with the highest cumulative yield per tree were G.16N and G.16T, and these were the only rootstocks with significantly greater yield than M.9. Cumulative yield efficiency was highest for Supporter 2 and lowest for M.9, but the differences were not significant. The rankings of rootstocks for fruit size were not consistent from year to year. M.9 has been a poor performer in this trial. M.26 performed better and only G.16T and G.16N, of the CG rootstocks, performed well enough to be recommended. In the 2001 Golden Delicious dwarf and semi-dwarf rootstock trials, in the fifth year of the dwarf trial, only CG.5890 had greater tree size (TCA) than the standard M.9. Root suckers were very prevalent with CG.4814. None of the rootstocks differed from the industry standards M.9 and M.26 in cumulative yield or cumulative yield efficiency. In the semi-dwarf trial, only one rootstock, CG.6589, had significantly larger trees (TCA) than the industry standard M.7 rootstock. M.7 and CG.6143 had a high number of root suckers. CG.6874 was the only rootstock with significantly greater cumulative yield and cumulative yield efficiency than M.7.

Impacts
The promising rootstock G.16 is recommended for trial by growers.

Publications

Autio, W.R., T.L. Robinson, B.H. Barritt, J.A. Cline, R.M. Crassweller, C.G. Embree, D.C. Ferree, M.E. Garcia, G.M. Greene, E.E. Hoover, R.S. Johnson, K. Kosola, J. Masabni, M.L. Parker, R.L. Perry, G.L. Reighard, S.D. Seeley and M. Warmund. 2005. Performance of Fuji and McIntosh apple trees after 5 years as affected by several dwarf rootstocks in the 1999 NC-140 apple rootstock trial. J. Amer. Pom. Soc. 59(4):202-214.
Autio, W.R., T.L. Robinson, B.H. Barritt, J.A. Cline, R.M. Crassweller, C.G. Embree, D.C. Ferree, M.E. Garcia, G.M. Greene, E.E. Hoover, R.S. Johnson, K. Kosola, J. Masabni, M.L. Parker, R.L. Perry, G.L. Reighard, S.D. Seeley and M. Warmund. 2005. Performance of Fuji and McIntosh apple trees after 5 years as affected by several semidwarf rootstocks in the 1999 NC-140 apple rootstock trial. J. Amer. Pom. Soc. 59(4):192-201.

Progress 01/01/04 to 12/31/04

Outputs
In a 1999 Fuji dwarf rootstock trial, tree size, measured as trunk cross-sectional area (TCA), was smallest for M.9 T337, and the tree sizes of Supporter 2, Supporter 1, M.26 EMLA, and Supporter 3 were not significantly larger than M.9 T337. Rootstocks significantly larger than M.9 in order of increasing tree size were the Cornell-Geneva (CG) rootstocks 4013, 5179, 16T, 16N, and 5935. On a cumulative basis, yield (kg/tree for 2001 to 2004) was highest for CG.16N and G.16T (the same rootstock with different propagation techniques). Cumulative yield efficiency (kg/cm2) was highest for two very dwarfing rootstocks, Supporter 1 and Supporter 2. M.26 also had high cumulative yield efficiency, but the standard dwarfing rootstock M.9 T337 had the lowest yield efficiency of all the rootstocks. The two rootstocks with the highest cumulative yield, C.16N and G.16T, also had the highest yield efficiency. Through year 6, M.9 T337, the dwarfing standard, has performed poorly (for no obvious reason) but the more vigorous dwarfing rootstock M.26 EMLA has performed well. Of the semi-dwarfing CG rootstocks, 16N and 16T have performed well. In a 2001 Golden Delicious dwarf and semi-dwarf rootstock trial, tree size (TCA) of four rootstocks, G.11, M.26, CG.5012, and CG.4814, was not significantly different from the standard dwarfing rootstock M.9. Trees on two rootstocks, CG.5890 and CG.4011, were significantly larger than trees on M.9. Yield (kg/tree) and yield efficiency (kg/cm2) in 2004 were low for all rootstocks in the trial. There was no significant difference among the rootstocks in cumulative yield or cumulative yield efficiency. One rootstock, CG.4814, had a relatively large number of root suckers.

Impacts
These rootstock trials are generally too young to draw meaningful conclusions. However, CG.16N and G.16T (variations of the same rootstock) appear to be promising and worthy of trial by Washington growers.

Publications

Autio, W., L. Anderson, B. Barritt, R. Crassweller, D. Ferree, G. Greene, S. Johnson, J. Masabni, M. Parker and G. Reighard. 2004. Early performance of Fuji apple trees on several dwarf rootstocks in the 1999 NC-140 rootstock trial. HortScience 39(4):800.
Autio, W., L. Anderson, B. Barritt, R. Crassweller, D. Ferree, G. Greene, S. Johnson, J. Masabni, M. Parker and G. Reighard. 2004. Early performance of Fuji apple trees on several semidwarf rootstocks in the 1999 NC-140 rootstock trial. HortScience 39(4):799.
Autio, W., L. Anderson, B. Barritt, J. Cline, R. Crassweller, C. Embree, D. Ferree, E. Garcia, G. Greene, E. Hoover, S. Johnson, K. Kosola, J. Masabni, M. Parker, R. Perry, G. Reighard and T. Robinson. 2004. Early performance of Fuji and McIntosh apple trees on several dwarf rootstocks in the 1999 NC-140 rootstock trial. 8th International Symposium on Integrating Canopy, Rootstock and Environmental Physiology in Orchard Systems. Pp. 93.
Autio, W., L. Anderson, B. Barritt, J. Cline, R. Crassweller, C. Embree, D. Ferree, E. Garcia, G. Greene, E. Hoover, S. Johnson, K. Kosola, J. Masabni, M. Parker, R. Perry, G. Reighard and T. Robinson. 2004. Early performance of Fuji and McIntosh apple trees on several semidwarf rootstocks in the 1999 NC-140 rootstock trial. 8th International Symposium on Integrating Canopy, Rootstock and Environmental Physiology in Orchard Systems. Pp. 94.
Barritt, B.H., B.S. Konishi and M.A. Dilley. 2004. The influence of 12 M.9 clones and 12 other dwarfing rootstocks on Fuji apple tree growth, productivity and susceptibility to southwest trunk injury in Washington. Acta Hort. 658:103-109.
Barritt, B.H., B.S. Konishi, M.A. Dilley and L. Pusey. 2004. Resistance of apple rootstocks to fire blight caused by Erwinia amylovora. Acta Hort. 658:387-390.
Robinson, T.L., L. Anderson, A. Azarenko, B.H. Barritt, G. Brown, J. Cline, R. Crassweller, P. Domoto, C. Embree, A. Fennell, D. Ferree, E. Garcia, A. Gaus, G. Greene, C. Hampson, P. Hirst, E. Hoover, S. Johnson, M. Kushad, R.E. Marini, R. Moran, C. Mullins, M. Parker, R. Perry, J.P. Prive, G. Reighard, C.R. Rom, T. Roper, J.R. Schupp, M. Warmund, W. Autio, W. Cowgill, K. Taylor and D. Wolfe. 2004. Performance of Cornell-Geneva rootstocks across North America in multi-location NC-140 rootstock trials. Acta Hort. 658:241-245.
Zhang, J., J. Sun and B. Barritt. 2004. Promising SH dwarfing apple rootstocks from China. Compact Fruit Tree 37(2):61-62.

Progress 01/01/03 to 12/31/03

Outputs
In a 1998 Jonagold trial tree size with G.16 was similar to M.9E while trees with CG.41 were larger than M.9E. Cumulative yield/tree in year 6 was proportional to tree size, and cumulative yield efficiency was similar for all 3 rootstocks. In a 1999 Fuji trial tree size with Supporter 2, Supporter 1, Supporter 3 and M.26 was not significantly different from M.9. CG.4013, CG.5179 and CG.16TC trees were not significantly larger than M.26. CG.16N and Supporter 4 were larger than M.26. Cumulative yield efficiency through year 5 was highest for Supporter 3, CG.16TC, Supporter 1, M.9, Supporter 2 and CG.16N and lowest for CG.4013 and Supporter 4. In a 1999 Fuji semi-dwarf trial, trees with CG.30TC and CG.30N were the largest in the trial and were significantly larger than M.26 and M.7. Trees on rootstocks CG.4814 and 4210 were not significantly larger than M.26. Cumulative yield and yield efficiency through year 5 were similar for all 7 rootstocks. In a 1999 Gala dwarf trial only trees of CG.4213 were significantly larger than M.9. Trees with CG.4214, 3041 and 4213 were not significantly different from M.26. Cumulative yield for CG.4213 was greater than all other rootstocks. Cumulative yield efficiency through year 5 was highest for M.9 and CG.3041 and M.26 had significantly lower yield efficiency than M.9. In a 1999 Gala semi-dwarf trial only trees with CG.6879 were significantly larger than trees with MM.106. Cumulative yield efficiency through year 5 for trees with CG.5046 was significantly higher than all other rootstocks.

Impacts
Promising rootstocks will be recommended for trial by growers.

Publications

Barritt, B.H. 2003. Selecting the components of an apple orchard system. pp. 3-6. In B.H. Barritt (Ed.) Apple Orchard Systems. IDFTA Compact Fruit Tree Vol. 36 Special Issue.
Robinson, T., L. Anderson, A. Azarenko, B. Barritt, T. Baugher, G. Brown, G. Couvillon, W. Cowgill, R. Crassweller, P. Domoto, C. Embree, A. Fennell, E. Garcia, A. Gaus, R. Granger, G. Greene, P. Hirst, E. Hoover, S. Johnson, M. Kushad, R. Moran, C. Mullins, S. Myers, R. Perry, C. Rom, J. Schupp, K. Taylor, M. Warmund, J. Warner and D. Wolfe. 2003. Performance of Cornell-Geneva apple rootstocks with 'Liberty' as the scion in NC-140 trials across North America. Acta Hort. 622:521-530.

Progress 01/01/02 to 12/31/02

Outputs
A 9-year-old NC-140 Gala dwarfing rootstock trial included 6 clones of M.9. Only M.9 Fleuren 56 trees were smaller than the other M.9 clones, and all M.9 clones had similar cumulative yield efficiency. Trees on B.9 were similar in yield and smaller in tree size than trees on M.9 clones. Trees on P.22, M.27E and B.491 were significantly smaller and had higher yield efficiency than trees on M.9, and trees on M.26E and V.1 were significantly larger and had significantly lower yield efficiency than trees on M.9. In a 9-year-old semi-dwarf NC-140 Gala trial M.26E, V.2 and G.30 were similar in tree size and yield efficiency. Preliminary data have been collected from trials of new Cornell-Geneva rootstocks established in 1998 and 1999.

Impacts
Data from trials help apple growers select adapted rootstocks that are most productive. M.9, M.26 and B.9 rootstocks are recommended based on current observations.

Publications

Robinson, T., L. Anderson, A. Azarenko, B. Barritt, G. Brown, J. Cline, R. Crassweller, P. Domoto, C. Embree, A. Fennell, D. Ferree, E. Garcia, A. Gaus, G. Greene, C. Hampson, P. Hirst, E. Hoover, S. Johnson, M. Kushad, R. Marini, R. Moran, C. Mullins, M. Parker, R. Perry, J.P. Prive, G. Reighard, C. Rom, T. Roper, J. Schupp and M. Warmund. 2002. Performance of Cornell-Geneva rootstocks in the North American NC-140 rootstock trials. Compact Fruit Tree 35(4):99-102.

Progress 01/01/01 to 12/31/01

Outputs
An 8-year-old NC-140 Gala dwarfing rootstock trial included 6 clones of M.9. Only M.9 Fleuren 56 trees were smaller than the other M.9 clones, and all M.9 clones had similar yield efficiency. Severe southwest trunk injury occurred on trunks of 9-year-old Fuji trees on 25 dwarfing rootstocks. The extent of trunk damage was associated with tree death during the subsequent years. The 13 clones of M.9 showed the most severe injury and highest tree mortality. A 1992 orchard systems trial with Fuji/M.9 and Braeburn/M.26 compared three orchard systems (Tatura trellis, double row and 'V' spindle) at 2500 trees/hectare with the hybrid tree cone (HYTEC) system at 1667 trees/hectare. There was no significant difference in cumulative yield through year 10 between the three orchard systems planted at 2500 trees/hectare, but each was more productive than the lower density HYTEC system. Preliminary data have been collected from trials of new Cornell-Geneva rootstocks established in 1998 and 1999.

Impacts
Data from trials help apple growers select adapted rootstocks that are most productive. M.9, M.26 and B.9 rootstocks are recommended based on current observations.

Publications

Hirst, P.M., Marini, R.P., Anderson, J.L., Autio, W.R., Barden, J.A., Barritt, B.H., Brown, G.R., Cline, J.A., Cowgill, W.P., Crassweller, R.M., Domoto, P.A., Ferree, D.C., Garner, J.M., Gaus, A., Greene, G.M., Hampson, C.R., Kushad, M.M., Meilke, E., Mullins, C.A., Parker, M.L., Perry, R.L., Prive, J.P., Reighard, G.L., Robinson, T.L., Rom, C.R., Roper, T., Schupp, J.R., Stover E., and Unrath, C.R. 2001. Early performance of 'Gala' on 18 dwarf and 4 semi-dwarf rootstocks growing at 24 sites in North America. Acta Hort. 557:199-208.
Marini, R.P., Barritt, B.H., Barden, J.A., Cline, J., Hoover, E.E., Granger, R.L., Kushad, M.M., Parker, M., Perry, R.L., Robinson, T., Khanizadeh, S., and Unrath, C.R. 2001. Performance of ten apple orchard systems: ten-year summary of the 1990 NC-140 systems trial. J. Amer. Pomological Soc. 55(4):222-238.
Marini, R.P., Barritt, B.H., Barden, J.A., Cline, J., Granger, R.L., Kushad, M.M., Parker, M., Perry, R.L., Robinson, T., Khanizadeh S., and Unrath, C.R. 2001. Performance of 'Gala' apple on eight dwarf rootstocks: ten-year summary of the 1990 NC-140 rootstock trial. J. Amer. Pomological Soc. 55(4):197-204.

Progress 01/01/00 to 12/31/00

Outputs
In a 9-year-old Liberty trial of 9 semi-dwarfing rootstocks G.30 was the most yield efficient, being much more productive than the industry standard, M.7. A 7-year-old Gala dwarfing rootstock trial included 6 clones of M.9. Only M.9 Fleuren 56 trees were smaller than the other M.9 clones, and all M.9 clones had similar yield efficiency. Severe southwest trunk injury occurred on Fuji trunks of trees on 25 dwarfing rootstocks. The extent of trunk damage was associated with tree death during the subsequent years. The 13 clones of M.9 showed the most severe injury and highest tree mortality. A 1992 orchard systems trial with Fuji/M.9 and Braeburn/M.26 compared three orchard systems (Tatura trellis, double row and 'V' spindle) at 2500 trees/hectare with the hybrid tree cone (HYTEC) system at 1667 trees/hectare. There was no significant difference in cumulative yield through year 9 between the three orchard systems planted at 2500 trees/hectare, but each was more productive than the lower density HYTEC system. Preliminary data have been collected from trials of new Cornell-Geneva rootstocks established in 1998 and 1999.

Impacts
Data from trials help apple growers select adapted rootstocks that are most productive. M.9, M.26 and B.9 rootstocks are recommended based on current observations.

Publications

Barritt, B.H. 2000. Selecting an orchard system for apples. Compact Fruit Tree 33(3):89-92.
Barritt, B.H. 2000. The HYTEC (Hybrid Tree Cone) orchard system for apples. Proceeding of the XXV International Horticultural Congress, Part 3. Acta Hort. 513:303-309.
Marini, R.P., Anderson, J.L., Barritt, B.H., Brown, G.R., Cline, J., Cowgill Jr., W.P., Domoto, P.A., Ferree, D.C., Garner, J., Greene, G.M., Hampson, C., Hirst, P., Kushad, M.M., Mielke, E., Mullins, C.A., Parker, M., Perry, R.L., Prive, J.P., Reighard, G.L., Robinson, T., Rom, C.R., Roper, T., Schupp, J.R., Stover, E., and Unrath, R. 2000. Performance of 'Gala' apple on four semi-dwarf rootstocks: A five-year summary of the 1994 NC-140 semi-dwarf rootstock trial. J. Amer. Pomological Soc. 54(2):84-91.
Marini, R.P., Anderson, J.L., Autio, W.R., Barritt, B.H., Cline, J.A., Cowgill Jr., W.P., Crassweller, R.M., Domoto, P.A., Ferree, D.C., Garner, J., Gaus, A., Greene, G.M., Hampson, C., Hirst, P., Kushad, M.M., Mielke, E., Mullins, C.A., Parker, M., Perry, R.L., Prive, J.P., Reighard, G.L., Robinson, T., Rom, C.R., Roper, T.R., Schupp, J.R., Stover, E., and Unrath, R. 2000. Performance of 'Gala' apple on 18 dwarf rootstocks: Five-year summary of the 1994 NC-140 dwarf rootstock trial. J. Amer. Pomological Soc. 54(2):92-107.

Progress 01/01/99 to 12/31/99

Outputs
In a 10-year-old Gala trial of 7 dwarfing rootstocks M.9 and B.9 had the highest yield efficiency. They had similar tree size and each produced larger trees than M.27 and smaller trees than M.26. In an 8-year-old Liberty trial of 9 semi-dwarfing rootstocks G.30 was the most yield efficient, being much more productive than the industry standard, M.7. A 6-year-old Gala dwarfing rootstock trial included 6 clones of M.9. Only M.9 Fleuren 56 trees were smaller than the other M.9 clones and all M.9 clones had similar yield efficiency. In a 1990 NC-140 orchard systems trial with Fuji and Braeburn, cumulative production through year 10 was closely related to initial tree density. A 1992 orchard systems trial with Fuji/M.9 and Braeburn/M.26 compared three orchard systems (Tatura trellis, double row and 'V' spindle) at 2500 trees/hectare with the hybrid tree cone (HYTEC) system at 1667 trees/hectare. There was no significant difference in cumulative yield through year 8 between the three orchard systems planted at 2500 trees/hectare but each was more productive than the lower density HYTEC system.

Impacts
(N/A)

Publications

Barritt, B.H. 1999. Batjer Memorial Lecture: Apple orchard systems--a global perspective. Proc. Wash. Sta. Hort. Assoc. 94:16-20, 22-39.
Barritt, B.H. 1999. Sistemas de conducao comporta-enxertos anoes em macieira (Apple orchard management). Proceedings (pp. 1-8) of Encontro Nacional Sobre Fruticultura de Clima Temperado (II ENFRUTE). Fraiburgo, Santa Catarina, Brazil.
Konishi, B.S. and B.H. Barritt. 1999. Performance of apple rootstocks in Washington: the influence of site and scion variety. Good Fruit Grower 50(16):55-58.

Progress 01/01/98 to 12/31/98

Outputs
In a 9-year-old Gala trial of 7 dwarfing rootstocks M.9 and B.9 had the highest yield efficiency. They had similar tree size and each produced larger trees than M.27 and smaller trees than M.26. In a 7-year-old Liberty trial of 9 semi-dwarfing rootstocks G.30 was the most productive, followed by M.7 and CG.210. A 5-year-old Gala dwarfing rootstock trial included 6 clones of M.9. Only M.9 Fleuren 56 trees were smaller than the other M.9 clones and all M.9 clones had similar yield efficiency. A 6-year-old Fuji trial of 28 dwarfing rootstocks planted at 3 sites included 13 clones of M.9. The most yield-efficient rootstocks were P.16 and P.22 (both extremely dwarfing), M.9 NAKB T339, V.3, P.2, M.9 NAKB T337 and B.9. The least yield efficient were MAC.39, O.3 (infected with virus), V.1, B.146, CG.10 and M.26. In a 1990 NC-140 orchard systems trial with Fuji and Braeburn, cumulative production through year 9 was closely related to initial tree density. A 1992 orchard systems trial with Fuji/M.9 and Braeburn/M.26 compared three orchard systems (Tatura trellis, double row and angled spindle) at 2500 trees/hectare with the hybrid tree cone (HYTEC) system at 1667 trees/hectare. There was no significant difference in cumulative yield through year 7 between the three orchard systems planted at 2500 trees/hectare but each was more productive than the lower density HYTEC system.

Impacts
(N/A)

Publications

Barritt, B.H. 1998. Orchard management systems for Fuji apples. Compact Fruit Tree 31(1):10-12.
Barritt, B.H. 1998. Sistemas de conduccion y poda en manzano-posicionamiento de las ramas principales (Apple tree training-pruning and limb positioning). Chpt. 6, pp. 1-20 in Curso Internacional de Fruticultura de Clima Templado-Frio. Mendoza, Argentina.

Progress 01/01/97 to 12/31/97

Outputs
Gala trees with 8 dwarfing rootstocks were compared in a 1990 NC-140 trial. M.27 was most dwarfing; Mark, B.9, MAC.39 & M.9 EMLA were intermediate; & O.3 & M.26 EMLA were most vigorous. Production efficiency (yield/tree divided by trunk cross-sectional area) was similar for M.27, Mark, B.9, MAC.39 & M.9, & was lower for O.3 & M.26. In a 1992 trial of Liberty with semi-dwarf rootstocks, the G.30 rootstock was similar in tree size to M.7 (a commercial standard) but G.30 was much more productive. In the 1994 NC-140 trial with Gala, five clones of M.9 were similar in tree vigor & productivity & were all larger than a sixth clone, M.9 Fleuren 56. In this trial, B.9 & V.3 were smaller trees than M.9 EMLA & had similar productivity to M.9. The largest & least productive trees in the trial were M.26 & V.1. Of the rootstocks tested in the 1987-88 NC-140 cherry rootstock trial, three are currently recommended for advanced orchard evaluation by growers: Gisela 5, a dwarfing precocious rootstock; Gisela 12, a semi-dwarfing precocious rootstock; & Gisela 6, a standard size precocious rootstock. These three rootstocks exhibited excellent precocity, productivity & apparent tolerance to viruses, excellent winter hardiness, good anchorage & low suckering.

Impacts
(N/A)

Publications

Barritt, B. H., et al. 1997 Performance of 'Gala' at year 5 with eight apple rootstocks in an 8-location North American NC-140 trial. Acta Hort. 451: In Press.
Barritt, B. H., S. R. Drake, B. S. Konishi & C. R. Rom. 1997. Influence of sunlight level & rootstock on apple fruit quality. Acta
Barritt, B. H., B. S. Konishi & M. A. Dilley. 1997. Tree size, yield & biennial bearing relationships with 40 apple rootstocks & three scion cultivars. Acta Hort. 451: In Press.
Lang, G., W. Howell, D. Ophardt & G. Mink. 1997. Biotic & abiotic stress responses of interspecific hybrid cherry rootstocks. Acta.
Perry, R., et al. 1997. Performance of the NC-140 cherry rootstock trials in North America. Acta Hort. 451: In Press.
Lang, G. 1997. Rootstock research & cherry breeding at WSU/Prosser. Proc. Wash. Sta. Hort. Assoc. 92: 275-280.
Lang, G., W. Howell & G. Mink. 1997. Virus tolerance & sensitivity of cherry rootstocks. Good Fruit Grower 48(10):22-26.
Lang, G. & L. Long. 1997. The sweet cherry genotype research consortium. Good Fruit Grower 48(10):14-15.

Progress 01/01/96 to 12/30/96

Outputs
In the 1990 Gala trial with 7 rootstocks, M.27 trees were smallest and O.3 and M.26 trees were largest. Cumulative yield efficiency was highest for M.9 EMLA, B.9 and Mark and lowest for M.26. In the 1992 Liberty trial with semi-vigorous rootstocks, trees on CG.179, CG.222, CG.30 and CG.210 were similar in size to M.7A. Yield efficiency was highest for CG.30. In the 1994 Gala trial with 21 dwarfing rootstocks, preliminary data to year 3 showed highest yield efficiency for B.491, P.16, V.3, M.9 Fleuren 56, O.3 and M.9 Nic 29. Differences in tree size and yield among six clones of M.9 were small.

Impacts
(N/A)

Publications

(B. H. Barritt one of 39 authors). 1996. Performance of the NC-140 cooperative apple rootstock planting: II. A 10-year summary of TCA, yield and yield efficiency at 31 sites. Fruit Var. J. 50:11-18.
Barritt, B. H. 1995. Apple rootstocks for intensive orchard systems. Michigan St. Hort. Soc. 125:57-65.
Barritt, B. H., B. S. Konishi and M. A. Dilley. 1996. Performance of three apple cultivars with 18 vigorous rootstocks during nine seasons in Washington. Fruit Var. J. 50:88-98. NC-140.
(B. H. Barritt one of 39 authors). 1996. Performance of the NC-140 cooperative apple rootstock planting: I. Survival, tree size, yield and fruit size. Fruit Var. J. 50:6-11. NC-140.

Progress 01/01/95 to 12/30/95

Outputs
Through 10 seasons & 3 cultivars, dwarfing rootstocks had significant effect on tree size & yield efficiency. With 23 dwarfing rootstocks, as tree size (trunk cross-sectional area, TCA) increased, yield efficiency (kg/cm2 TCA) decreased. For tree size & yield efficiency, ranking of rootstocks was generally similar with each cultivar. Fruit weight was not related to vigor of rootstocks. B.9, M.9 EMLA, O.3 & M.26 EMLA had largest fruit size. Most promising rootstocks were V.3, P.2, M.9 EMLA, V.1, B.9, O.3 & M.26 EMLA. Through year 9 w/3 cultivars & 18 vigorous rootstocks, largest rootstocks generally had lowest yield efficiency. For tree size & cumulative yield efficiency, rootstock ranking was generally similar w/each variety. Number of root suckers was highest w/MAC.24, M.7A, M.4, M.7 EMLA & A.313, & poorest anchorage occurred w/M.2 EMLA. M.7A, B.118, M.4 & M.7 EMLA. Most precocious rootstocks (based on 3rd year bloom) were B.118, MM.106, MM.111 EMLA, MM.106 EMLA & M.7 EMLA. Fruit size differences between rootstocks were small. Best overall performance occurred w/MM.106, M.7 & MM.111. In 6th year of Gala trial w/7 dwarfing rootstocks, M.27 EMLA had smallest tree size. Mark, B.9, MAC.39 & M.9 EMLA were similar in size & larger than M.27 EMLA. O.3 & M.26 EMLA had largest tree size. Cumulative yield/tree was highest w/M.9 EMLA & 0.3, & yield efficiency was highest for M.9 EMLA, Mark & B.9. In year 6, Mark & M.27 EMLA had significantly smaller fruit size than other 5 rootstocks.

Impacts
(N/A)

Publications

Progress 01/01/94 to 12/30/94

Outputs
In an evaluation of 23 rootstocks with Golden Delicious, Granny Smith and Delicious during eight seasons, rootstocks in the very dwarf category, P.16, P.22 and V.3, had greater yield efficiency and had larger fruit size than the super dwarf standard M.27E. P.2, V.1, B.9 and O.3, in comparison with M.9E, had similar precocity and large fruit size. Mark performed poorly with declining vigor, small fruit size, extensive root suckering and swelling at the soil line. In the M.26E to M.7A size range, V.2 and V.7 showed promise. P.1 and OAR.1, similar to M.7A in tree size, have low production and small fruit size. Although the weakest rootstocks, P.16, P.22 and V.3, had high yield efficiency, they produced very short shoots and insufficient leaf area to protect fruit from sunburn. Rootstock ranking for tree size and yield efficiency were generally similar with each cultivar. In a 1990 Gala trial, M.26E and O.3 trees were larger than trees with B.9, M.9E, Mark and MAC.39 which were larger than M.27E trees. M.9E and O.3 had the highest production per hectare. Yield efficiency was highest with M.9E and lowest with M.26E. A 1992 trial with 12 new Cornell-Geneva (CG) fire blight and collar rot resistant rootstocks was productive in 1994 but third year performance is not conclusive. In 1994 an NC-140 Gala trial of 25 new rootstocks, including six clones of M.9 and 4 CG rootstocks, was established at TFREC and at 25 other North American sites.

Impacts
(N/A)

Publications

Progress 01/01/93 to 12/30/93

Outputs
1984 NC-140 Apple Rootstock Trial (Starkspur Supreme Delicious). In the tenth year, two very dwarfing rootstocks, P.22 and P.16, produced trees one-third the size of trees on M.26E with cumulative yield efficiency twice that of M.26E. Four rootstocks, P.2, CG.10, B.9 and MAC.9, produced trees similar to our slightly smaller than M.26E with yield efficiency generally similar to M.26E. Of the more vigorous rootstocks in the trial (M.7E, P.1, M.4, MAC.1, B.490, seedling, A.313 and P.18), M.7E produced the smallest trees and had the highest yield efficiency. 1986 Dwarf Apple Rootstock Trial (Golden Delicious, Granny Smith and Delicious). After year 8, rootstocks fell into the following three categories (for comparison M.9E=100): 1) very dwarf: M.27E (35), P.16 (43), P.22 (57), MAC.39 (58), V.3 (59), B.146 (60), Mark (66), M.9 with virus (72) and CG.10 (79); 2) dwarf: P.2 (87), M.9E (100), V.1 (105), B.9 (117), O.3 (128), MAC.39 (134) and M.26E (155); and 3) semi-dwarf: C6 (173), V.7 (174), V.2 (189), M.7A (193), OAR.1 (234), P.1 (272) and V.4 (274). Yield efficiency was generally highest for the very dwarf, intermediate for the dwarf and lowest for the semi-dwarf rootstocks. Fruit size, averaged over 5 years with three varieties and adjusted for crop load, was generally large except for OAR.1, P.1, MAC.9, M.27E, B.146 and Mark, which had smaller fruit. The most promising rootstocks for high density plantings based on this trial are P.2, M.9E, V.1, B.9, O.3 and M.26E.

Impacts
(N/A)

Publications

Progress 01/01/92 to 12/30/92

Outputs
Rootstock Trial (Starkspur Supreme Delicious). P.22 and P.16 produced much smaller trees than P.2, CG.10, Bud.9 and MAC.39, which fell between M.9 and M.26 in tree size. Yield efficiency in kg/trunk cross-sectional area (kg/TCSA) for years 1990 through 1992 was highest for the more dwarfing rootstocks with P.16, Bud.9, P.22 and P.2 being the highest. 1986 Dwarfing Rootstock Trial (Golden Delicious, Granny Smith and Delicious). In year 7 tree size in comparison with M.9 EMLA (=100) was M.27 EMLA (39), P.16 (48), V.3 (61), P.22 (61), Mark (69), M.9 (not virus-free) (72), P.2 (89), V.1 (108) and Bud.9 (118). Yield efficiency (kg/TCSA) for these rootstocks was generally equal to M.9 EMLA except for M.27 EMLA, which was lower. Tree size for rootstocks in the M.26 size range (size=157 compared with M.9 EMLA=100) include O.3 (135), V.7 (156) and V.2 (183). Yield efficiency of these rootstocks was lower than M.9 EMLA and comparable to M.26 EMLA. Three rootstocks in the M.7 vigor range, V.4, P.1 and OAR.1, had low yield efficiency. 1986 Vigorous Rootstock Trial (Golden Delicious, Granny Smith and Delicious). In year 6 tree size comparisons with MM.106 EMLA (=100) were M.7A (78), M.7 EMLA (94), A.306 (95), M.2 EMLA (102), MM.111 (104), P.13 (112), M.4 (118), MAC.16 (122), MAC.1 (124), Bud.118 (128), MM.104 (125), P.18 (137), A.313 (146), MAC.4 (145) and MAC.24 (175). Yield efficiency (kg/TCSA) was relatively high and similar to MM.106 EMLA for M.7A, P.13, Bud.118 and MAC.4.

Impacts
(N/A)

Publications

Progress 01/01/91 to 12/30/91

Outputs
1984 NC-140 Apple Rootstock Trial. In the eighth year with 'Starkspur Supreme Delicious' the dwarf rootstocks P.22, P.16 and P.2 produced smaller trees (smallest trunk cross-sectional area (TCSA)) than M.26 while C.6, MAC.39, Bud.9 and CG.10 produced trees similar to M.26 in size. All of the above rootstocks produced smaller trees than M.7 and the more vigorous rootstocks (in order of increasing tree size) were CG.24, P.1, MAC.1, Seedling, Bud.490, A.313, M.4 and P.18. Yield efficiency (kg/cm2 TCSA) was greatest for P.2, P.16, Bud.9, P.22 and M.26. 1986 Dwarf Apple Rootstock Trial. In 1986 ten trees each of 'Smoothee Golden Delicious', 'Granny Smith' and 'Redchief Delicious' were planted on 22 dwarfing rootstocks. Each tree was supported with a stake and trained to the slender spindle system. Based on TCSA, trees that were smaller than M.9 EMLA were M.27, P.16, V.5-3, P.22, Bud.146, MAC.9, M.9 and Mark. Trees that were similar to M.9 EMLA in size were P.2, CG.10, V.5-1 and Bud.9. Trees that were larger than M.9 EMLA were on MAC.39, O.3, M.26, V.5-7, C6 and V.5-2. The largest trees in the trial, equivalent in size to M.7, were OAR.1, P.1 and V.5-4. Cumulative yield efficiency (kg/cm2 TCSA for years 3-6) with 'Golden Delicious' and 'Granny Smith' was highest for V.5-3, P.16, MAC.9, P.22 and Mark and lowest for the most vigorous rootstocks C6, V.5-2, OAR.1, P.1 and V.5-4. With 'Delicious', the most yield efficient rootstocks were V.5-7, Bud.9, P.2, O.3 and M.9 EMLA.

Impacts
(N/A)

Publications

Progress 01/01/90 to 12/30/90

Outputs
1984 NC-140 Apple Rootstock Trial ('Starkspur Supreme Delicious' scion). Of the weak group of rootstocks, P.22 and P.16 had smaller tree size than M.26 EMLA, while P.2, CG.10, B.9 and MAC.39 were similar to M.26 EMLA. Of the strong group of rootstocks P.1 was similar to M.7 EMLA while the remaining rootstocks (MAC.1, Seedling, B.490, M.4, A.313, P.18) had greater tree size than M.7 EMLA. Yield efficiency (kg/TCSA) was greatest for P.22 and P.16 followed by B.9, P.2, CG.10 and C6. The rootstocks larger than M.7 EMLA had low yield efficiency. 1986 Dwarfing Rootstock Trial. In 1986 ten trees each of 'Smoothee Golden Delicious' 'Granny Smith' and 'Redchief Delicious' were planted on 22 dwarfing rootstocks. Each tree was supported with a stake and trained to the slender spindle system. Trees that were smaller than M.9 EMLA were M.27 EMLA, P.16, P.22, V 5-3, Mark, MAC.9, EM.9 and B.146. Trees that were similar to M.9 EMLA in size were CG.10, P.2, V 5-1 and MAC.39. Trees that were larger than M.9 EMLA were Ott 3, B.9, C6 V 5-2, V 5-7 and M.26 EMLA. The most yield efficient group of rootstocks included V 5-3, M.9 EMLA, V 5-1 and MAC.9. The rootstocks C.6, M.27 EMLA and M.26 EMLA had low hield efficiency. 1986 Vigorous Rootstock Trial. Three varieties, each on 20 vigorous apple rootstocks, were planted as free-standing trees and central leader trained. The most yield efficient rootstocks were MM.106, M.4, B.118 and the least efficient were MAC.24, ANT 313, ANT 306 and MAC.16.

Impacts
(N/A)

Publications

Progress 01/01/89 to 12/30/89

Outputs
1980 NC-140 Apple Rootstock Trial (`Starkspur Supreme Delicious' scion): Fruit production/acre in the 10th year, adjusted for an appropriate tree density based on actual tree size, was greatest for EMLA 26 and EMLA 27, slightly lower for Ott 3, EMLA 7, M 9 and EMLA 9 and considerably lower for MAC 9, OAR 1 and MAC 24. With MAC 9 extensive tumor and gall-like growth which was infested with woolly apple aphid occurred all the way around the rootstock near the soil line. 1984 NC-140 Apple Rootstock Trial (`Starkspur Supreme Delicious' scion): Among the vigorous rootstocks (in order of decreasing tree size) P 18, Ant 313, Seedling, M 4, MAC 1, Bud 490, P 1, EMLA 7 and CG 24, only EMLA 7 (26.8 kg/tree) was highly productive in years 4 to 6. Dwarf rootstocks in the trial had the following cumulative yield (kg/tree) in years 4 to 6: (in order of decreasing tree size) C 6 (25.1), Bud 9 (20.8), MAC 39 (12.8), CG 10 (13.1), EMLA 26 (22.7), P2 (16.0), P 16 (12.0) and P 22 (8.6). The dwarfing rootstocks had greater yield/ha than EMLA 7 and the more vigorous rootstocks when yield/tree was adjusted for the appropriate tree density. 1986z Dwarfing Rootstock Trial: This planting includes 25 dwarfing rootstocks each with `Smoothee Golden Delicious', `Granny Smith' and `Redchief Delicious' scions. Rootstocks with tree size similar to EMLA 26 were Ott 3, C 6, V5-7 and V5-2. In this group, V5-2 and V5-7 and EMLA 26 had the highest cumulative third and fourth year production.

Impacts
(N/A)

Publications

Progress 01/01/88 to 12/30/88

Outputs
In the 1980 NC-140 rootstock trial with Starkspur Supreme Delicious scion the largest trees, MAC 24 and EMLA 7, had the highest yield per tree, and the smallest trees, EMLA 9, M9, MAC 9 (Mark) and EMLA 27, had the smallest yield per tree. When rootstock yield was adjusted for the appropriate tree density based on actual tree size the most productive rootstocks were EMLA 27, Ottawa 3, MAC 9 (Mark) and EMLA 7, and the least productive were MAC 24 and OAR 1. After 9 years of evaluation Mark can be recommended for commercial use while MAC 24 and OAR 1 will not be recommended for commercial use. In the 1984 NC-140 trial with Starkspur Supreme Delicious scion nine rootstocks produced trees equal to or larger than EMLA 7 (in order of decreasing size, P 18, M 4, seedling, MAC 1, Ant 313, P 1, Bud 490, EMLA 7 and CG 24); and eight rootstocks produced trees that were equal to or smaller than EMLA 26 (in order of decreasing tree size, C 6, Bud 9, EMLA 26, CG 10, MAC 39, P 2, P 16, and P 22). The greatest combined fourth and fifth year production per tree occurred with C 6, EMLA 7, Bud 9 and EMLA 26. The lowest production was with Ant 313, seedling and MAC 1, all vigorous rootstocks. The 1986 trial of 25 dwarf and 20 vigorous rootstocks each with three varieties, Granny Smith, Smoothee Golden Delicious and Redchief Delicious grew well and had a light crop in 1988. The 1987 trial of 100 New York apple rootstock selections grew well but did not crop in 1988.

Impacts
(N/A)

Publications

Progress 01/01/87 to 12/30/87

Outputs
In the 1980 rootstock trial (Regional Project NC-140) with Starkspur Supreme Delicious, MAC 24 trees were largest, suckered badly and cropped poorly. OAR 1 and EMLA 7 were similar in tree size but smaller than MAC 24 and had the highest yield/tree and, when adjusted to an appropriate tree density, had the highest per-acre yields. EMLA 26 and Ott 3 were similar in size and production and were less productive than OAR 1 and EMLA 7. EMLA 9, MAC 9 (Mark) and M 9 were equal in tree size and productivity. EMLA 27 was extremely stunted and unproductive. Rootstocks with less vigor than EMLA 7 have not been suitable for this weak growing spur strain of Delicious. In the 1984 trial with Starkspur Supreme, rootstocks fell into two distinct vigor groups (listed from largest to smallest): the vigorous group, P 18, M 4, P 1, seedling, ANT 313, MAC 1, EMLA 7, Bud 490 and CG 24; and the dwarf group, C6, Bud 9, EMLA 26, MAC 39, CG 10, P 2, P 22 and P 16. The greatest fourth leaf production (kg/tree) was with C6 (6.8), EMLA 27 (6.0) and P 2 (5.4). The trial of 45 apple rootstocks each with three scion cultivars, Granny Smith, Golden Delicious and Redchief Delicious, grew well in 1987 but did not have a crop. A trial of 150 NY rootstock selections was established.

Impacts
(N/A)

Publications

Progress 01/01/86 to 12/30/86

Outputs
The apple dwarfing rootstock trial planted in 1980 (Regional Project NC-140) with Starkspur Supreme Delicious fruited for the third year. Cumulative yields (kg/tree) for rootstocks listed in order of decreasing tree size were: MAC 24, 2.0; EMLA 7, 9.1; OAR 1, 5.8; Ottawa 3, 7.7; EMLA 26, 3.8; MAC 9 (Mark), 3.5; EMLA 9, 4.6; M 9, 1.1; and M27, 0.4. MAC 24 was vigorous, unproductive and suckered badly. The trees in the trial continue to show poor growth due to site and replant problems. In the 1984 NC-140 rootstock trial with Starkspur Supreme Delicious the rootstocks fell into two fairly distinct groups. The vigorous group (P 18, P 1, MAC 1, seedling, M.4, EMLA 7, Ant 313, Bud 491, CG 24, Bud 490 and own root) had the largest trunk circumference, tree height and spread and had very few flower clusters. The dwarf group (C 6, Bud 9, EMLA 26, MAC 39, P 2, CG 10, P 22 and P 16) were all smaller in circumference and height than any rootstock in the vigorous group and had a greater number of flower clusters per tree. Two trees each of CG 24, P 2, P 16 and own root and one tree each of P 22, C 6 and CG 10 showed severe leaning. Trees in the trial continue to grow well. Granny Smith, Smoothee Golden Delicious and Redchief (Campbell) Delicious were each planted on 45 rootstocks with 10 individual tree replications of each rootstock/scion combination.

Impacts
(N/A)

Publications

Progress 01/01/85 to 12/30/85

Outputs
The apple dwarfing rootstock trial planted in 1980 (Regional Project NC-140) with Starkspur Supreme Delicious fruited for the second year. Cumulative yields (kg/tree) for rootstocks listed in order of decreasing tree size were: MAC 24, 1.0; EMLA 7, 4.5; OAR 1, 3.8; Ottawa 3, 6.9; EMLA 26, 3.0; MAC 9 (Mark), 2.9; EMLA 9, 3.6; M 9, 1.1; and M 27, 0.2. MAC 24 was vigorous, unproductive and suckered badly. Ottawa 3 tress leaned badly. In the 1984 rootstock trial with Starkspur Supreme Delicious the most vigorous rootstocks with growth greater than M 7 were seedling, ANT 313, P 1, P 18 and M 4. Rootstocks with intermediate tree size between M 7 and M 26 were MAC 1, CG 24, BUD 491, BUD 490, BUD 9, and C 6. Rootstocks with less tree growth than M 26 were P 22, MAC 39, CG 10, P 16 and P 2. Resistance of apple rootstocks to collar rot caused by Phytophthora cactorum was evaluated using laboratory inoculation techniques. Rootstocks P 18, EMLA 106, MAC 1, P 1 and BUD 490 were very susceptible; M 4, EMLA 7 and EMLA 26 were susceptible; C 6 and CG 24 were moderately resistant; and P 2, P 22, B 9, MAC 39 and Mark were resistant.

Impacts
(N/A)

Publications

Progress 01/01/84 to 12/30/84

Outputs
The apple dwarf rootstock trail planted in 1980 (Regional Project NC-140) with Starkspur Supreme Delicious scion fruited for the first time in 1984. Yields (kg/tree) for rootstocks listed in order of decreasing tree size were as follows: MAC 24, 0.3; EMLA 7, 3.5; OAR 1, 2.9; Ottawa 3, 3.7; EMLA 26, 2.0; Mark, 1.5; EMLA 9, 1.8; M 9, 0.6; and EMLA 27, 0.2. Ottawa 3 trunks leaned severely and MAC 24 trees suckered badly and lacked precosity. A new apple rootstock trial was planted in 1984 with Starkspur Supreme Delicious as the scion. The following rootstocks were included: P (Poland) 1, kP 2, P 16, P 18, P 22, Bud (Budagovski, Russian) 9, Bud 490, Bud 491, MAC (Michigan apple clone) 1, MAC 39, CG (Cornell-Geneva) 10, CG 24, M 4, C 6, Antonovka 313, EMLA 7, EMLA 26, seedling and own-rooted scion.

Impacts
(N/A)

Publications

Progress 01/01/83 to 12/30/83

Outputs
The dwarfing rootstock trial, Regional Project NC-140, in its fourth leaf with Starkspur Supreme Delicious scion did not crop in 1983. Trees on M 27 were 10% smaller, based on trunk circumference, than trees on M 9 which in turn were 27% smaller than trees on EMLA 9. Mark and M 26 trees were similar in size to those on EMLA 9. Ottawa 3 trees were 60% larger and OAR 1 trees 70% larger than trees on M 9. The largest trees were on M 7 and MAC 24, 106% and 130% larger than M 9, respectively. MAC 24 trees suckered badly. In laboratory screening tests for susceptibility to collar rot, caused by Phytophthora cactorum, MM 106 and MAC 24 wee susceptible and M 9 and Mark fairly resistant. Rootstock susceptibility varied depending on the date samples were taken from the field. M 27 was susceptible in April but resistant in June while M 26 was resistant in April and susceptible in June. Tree sites for a replicated 19-rootstock trial were fumigated and the irrigation system installed in preparation for spring 1984 planting.

Impacts
(N/A)

Publications

Progress 01/01/82 to 12/30/82

Outputs
As part of a national (NC-140) rootstock evaluation project including 22 states,9 dwarfing rootstocks with 'Starkspur Supreme Delicious' as the scion were planted in 1980 and 1981. None fruited in 1982. Trunk circumference growth was used to evaluate vegetative growth. EMLA 27 was very dwarfing with 10% less growth than the standard dwarfing rootstock M 9. In relation to M 9 and in order of increasing tree vigor were EMLA 9 (20% increase), EMLA 26 (21% increase), Mark (26% increase), Ottawa 3 (45% increase), OAR 1 (56% increase), EMLA 7 (68% increase), and MAC 24 (100% increase). The relative growth rate of these rootstocks in Washington has been similar to that observed in the other 22 states.

Impacts
(N/A)

Publications

Progress 01/01/81 to 12/30/81

Outputs
Five replications of a national apple rootstocktrial (NC 140) were planted adjacent to five replications that were planted in 1980. The scion variety is 'Starkspur Supreme Delicious'. The nine rootstocks were selected for their potential to control growth of the scion. As a measure of tree vigor trunk circumference measurements were made in 1981 on the trees planted in 1980. The growth controlling characteristics in relation to the dwarfing M 9 rootstock were as follows EMLA 27 had a decrease of 7% in growth compared to M 9; EMLA 26, EMLA 9, OAR 1, 'Marc' (MAC 9), Ottawa 3, EMLA 7 and MAC 24 all had increased growth over M 9 of 30, 32, 39, 41, 57, 64 and 89% respectively. Trees on an additional 20 rootstocks are being propagated for a 1984 planting.

Impacts
(N/A)

Publications

Progress 01/01/80 to 12/30/80

Outputs
A planting of Starkspur Supreme Delicious was made in 1980 on nine rootstocks: M 9, EMLA 7, 9, 26 and 27, Ottawa 3, ORA 1, MAC 9 and 24. Pollenizers were Macspur and Starkspur Golden Delicious on M 26. Five replication were planted. This is part of the national NC-140 project to evaluate apple rootstocks. Five additional replications will be planted in 1981 and planning is underway for planting of 10 new rootstocks.

Impacts
(N/A)

Publications

Progress 01/01/79 to 12/30/79

Outputs
The effect of commonly used rootstocks on growth and productivity of 'Delicious'and 'Golden Delicisou' apple trees has been investigated. During the first nine years the fruiting habit of the scion had as strong an influence on growth and productivity as did any of the rootstocks tested. In subsequent years, however, the dwarfing effect of the clonal rootstock became apparent and it was much easier to maintain trees on clonal dwarfing rootstocks in a productive condition. The spur-type fruiting habit of the scion was also found to be important in this respect. Preparations have been made to establish a new rootstock planting in the Spring of 1980 which will include EMLA 7, 9, 26, ORA 1, MAC 9, 14 and Ottawa 3. This is the first scientific trial in the northwest in which these materials have been included. Preparations are being made for additional trials including a 1983 planting which will include selections from the Polish, Budgaovsky, MAC and Ottawa series.

Impacts
(N/A)

Publications