November 1997



Project Leader: Wesley R. Autio

Cooperators: Duane W. Greene & Daniel R. Cooley



PROGRESS AND PRINCIPAL ACCOMPLISHMENTS



1990 NC-140 Apple Cultivar/Rootstock Trial

As part of the 1990 NC-140 Apple Cultivar/Rootstock Trial, Golden Delicious, Jonagold, Empire, and Rome trees on M.9 EMLA, B.9, Mark, O.3, and M.26 EMLA were planted in a randomized-complete-block/split-plot design with five replications at the University of Massachusetts Horticultural Research Center (Belchertown, MA). Scion cultivar represented the whole plot, and rootstock represented the split plot. Scion cultivar and rootstock interacted to affect trunk cross-sectional area (TCA) at the end of the 1997 growing season (Table 1). Generally, differences among rootstocks were greatest for Jonagold and Empire and nonsignificant for Golden Delicious. Using, the results of mean separation to identify consistent rootstock effects, it can be seen that trees on Mark and those on B.9 consistently were in the lowest category with each scion cultivar. Further, trees on M.26 EMLA were consistently in the highest category with each scion cultivar. Trees on O.3 were similar to those on M.26 EMLA for Golden Delicious and Rome and significantly smaller with Empire. Trees on M.9 EMLA were in the smallest statistical grouping, except with Rome, where they were similar in size to trees on M.26 EMLA. Overall rootstocks, the TCA of Rome and Jonagold trees were significantly greater than TCA of Golden Delicious and Empire trees.

Rootstock and scion cultivar affected yield per tree in 1997 but did not interact significantly (Table 1). Greatest yields were harvested from trees on O.3 and M.26 EMLA, and the lowest yields were harvested from trees on Mark. Trees on M.9 EMLA and those on B.9 were intermediate. Rome trees yielded the most in 1997, and Empire tree yielded the least.

Cumulative yields per tree (1992-97) were affected by rootstock, scion cultivar, and the interaction of the two (Table 1). Overall scion cultivars, O.3 resulted in the greatest cumulative yields per tree, and B.9 and Mark resulted in the lowest. Likewise, O.3 was in the highest statistical category consistently across scion cultivars, and Mark and B.9 were consistently in the lowest category across cultivars. M.9 EMLA resulted in cumulative yields in the lowest category for Golden Delicious and Jonagold and in the highest category for Empire and Rome. M.26 EMLA resulted in yields in the lowest category for Golden Delicious, the highest category for Jonagold, and intermediate for Empire and Rome. Across all rootstocks, Rome resulted in the greatest cumulative yields, and Empire resulted in the lowest.

Scion cultivar did not affect yield efficiency in 1997 or cumulatively (1992-97), and scion cultivar and rootstock did not interact to affect either assessment (Table 2). Rootstock, however, affected yield efficiency both in 1997 and cumulatively. In both situations, M.26 EMLA resulted in the lowest efficiency, and the other rootstocks resulted in similar efficiencies.

Rootstock and the interaction of rootstock and scion cultivar did not affect fruit weight in 1997 (Table 2). All scion cultivars, however, differed from each other. Largest fruit were from Rome, followed by Jonagold, Golden Delicious, and Empire, in descending order.

Trees in the Massachusetts portion of the 1990 NC-140 Apple Cultivar/Rootstock Trial were somewhat poor at the outset. Lateral branching has been uneven with some trees, and scion rooting has been a constant concern. With these problems, however, trees have done well, with average cumulative yield exceeding 108 kg per tree. In 1997, yields per tree exceeded 22 kg on average, and fruit size was nearly 210 g (approximately 90 count). Although scion cultivar and rootstock have interacted to affect tree size and yield per tree in this planting, no startling interactions have occurred.



1994 NC-140 Apple Rootstock Trial

As part of the 1994 NC-140 Apple Rootstock Trial, a planting of Gala on 17 rootstock was established at the University of Massachusetts Horticultural Research Center in 1994. The planting included ten replications in a randomized-complete-block design. TCA, yield per tree, and yield efficiency in 1997 all were affected by rootstock in this trial (Table 3). Largest trees were on V.1, Pajam 1, and M.26 EMLA, and the smallest trees were on P.16, B.491, and P.16. In 1997, trees on Mark and V.1 yielded the most, and those on M.9 RN29, M.9 Fleuren 56, P.22, M.9 EMLA, and M.27 EMLA yielded the least. Cumulatively (1996-97), trees on Mark and V.1 yielded the most and those on P.22, P.2, and M.27 EMLA yielded the least. The most yield-efficient trees in 1997 were on B.9, P.16, B.491, and P.22, and the least yield-efficient trees were on M.9 Pajam 1, M.26 EMLA, M.9 Pajam 2, P.2, M.9 EMLA, and M.9 RN29. Rootstock did not affect fruit weight in 1997 (Table 3).

Bloom density was affected by rootstock in 1997 (Table 4). P.16, P.22, Mark, and B.469 resulted in the greatest spur bloom density, and M.9 Pajam 1, M.9 Pajam 2, and M.9 EMLA resulted in the lowest spur bloom density. The density of blossoms borne laterally on one-year-old wood was not affected by rootstock in 1997. Total bloom density was greatest for trees on O.3, B.9, P.22, B.491, and B.469 and lowest for trees on M.9 Pajam 1, M.9 EMLA, and P.2.

Fruit set also was affected by rootstock in 1997 (Table 5). Total fruit set, expressed as the number per cm2 limb cross-sectional area, was greatest for trees on Mark and P.22 and lowest for trees on M.26 EMLA, M.9 RN29, M.9 EMLA, and P.2. Total fruit set, expressed as the number per 100 blossom clusters, was also greatest for trees on Mark and P.22 and lowest for trees on M.9 Pajam 2, M.26 EMLA, M.9 RN29, M.9 EMLA, and P.2. Because there is a significant difference in fruit size for laterally-borne and spur-borne Gala fruit, the portion of total set that occurred laterally on one-year-old wood also was assessed (Table 5, Figure 1). Over 40% of the crop on trees on M.9 NAKBT337 and M.9 RN29 was borne laterally on one-year-old wood. On the other hand, less than 20% of the crop on trees on M.26 EMLA, Mark, and P.2 was borne laterally on one-year-old wood. Enhancement of the percent of the crop borne on spurs may be a criterion for selecting rootstocks to be used with Gala as the scion.

Since there are several strains of M.9 included in this study, it is interesting to isolate and compare them specifically. Strain differences affected TCA (Table 4), with trees on M.9 Pajam 1 the largest, followed, in descending order, by those on M.9 RN29, M.9 Pajam 1, M.9 EMLA, M.9 NAKBT337, and M.9 Fleuren 56. Trees on M.9 Fleuren 56 on average were only 55% of those on M.9 Pajam 2. Yield was not affected by M.9 strain, but bloom density was altered (Table 5). Trees on M.9 NAKBT337 had a significantly higher spur bloom density than trees on M.9 EMLA, with other strains resulting in intermediate densities. Total bloom density of trees on M.9 NAKBT337 and M.9 RN29 was significantly greater than the bloom density of trees on M.9 Pajam 1 and M.9 EMLA. M.9 Pajam 2 and M.9 Fleuren 56 resulted in intermediate total bloom density. Total fruit set was not affected by M.9 strain, but the percent of set on one-year-old wood was significantly greater for trees on M.9 RN29 than those on M.9 NAKBT337 (Table 5, Figure 1). Other strains resulted in intermediate percentages.



1994 NC-140 Peach Rootstock Trial

As part of the 1994 NC-140 Peach Rootstock Trial, a planting of Redhaven on 13 rootstocks was established at the University of Massachusetts Horticultural Research Center in 1994. The planting included eight replications in a randomized-complete-block design. Rootstock affected TCA of trees at the end of the 1997 growing season (Table 6). Trees on Guardian and Lovell were the largest, and those on Rubira and Ishtara were the smallest. The TCA of trees on Rubira and Ishtara was 59% and 39%, respectively, of the TCA of trees on Lovell. Date of 90% bloom was not affected by rootstock in 1997 (Table 6), but rootstock affected the date of 10% maturity (as measured by commercial harvest). Trees on Ta Tao/Lovell were significantly later than all others, but there were no differences among the trees on the other rootstocks. Some peach tree borer damage has occurred in this planting. In 1997, the extent of damage was rated, and it was observed that the lowest borer damage occurred in trees on Ishtara (Table 6).

Fruit weight, yield in 1997, and cumulative yield (1996-97) were not affected by rootstock; however, rootstock affected yield efficiency (Table 7). Both in 1997 and cumulatively, trees on Ishtara were the most yield efficient, and trees on Montclar were the least yield efficient.



1990 Liberty Rootstock Trial

In the guard rows of the 1990 Apple Cultivar/Rootstock Trial, a small trial was established in 1990. It includes Liberty on M.7, M.9, and M.26 in a randomized-complete-block design with seven replications (Table 8). At the end of the 1997 growing season, the largest Liberty trees were on M.7, followed by those on M.26, and those on M.9 were the smallest. Trees on M.7 yielded significantly less in 1997 than trees on M.26, and trees on M.9 yielded intermediately . Cumulatively (1992-97), trees on M.26 yielded the most, followed by those on M.7 and M.9. Yield efficiency in 1997 and cumulatively was significantly greater for trees on M.9 and M.26 than for trees on M.7. Fruit weight was greatest in 1997 from trees on M.7.



1990 McIntosh Rootstock Trial

A second planting was included in the guard rows of the 1990 Apple Cultivar/Rootstock Trial including Marshall McIntosh on M.9 EMLA, B.9, and M.26 EMLA in a randomized-complete-block design with five replications (Table 9). Trees on M.26 EMLA were the largest at the end of the 1997 growing season, followed by those on M.9 EMLA, and those on B.9. Rootstock did not affect yield per tree in 1997 or cumulative yield per tree (1992-97). Yield efficiency in 1997 was greatest for trees on B.9, followed by those on M.9 EMLA, and those on M.26 EMLA. Cumulatively, trees on M.9 EMLA and B.9 were significantly more efficient than those on M.26 EMLA. M.26 EMLA resulted in significantly larger fruit than did the other two rootstocks in 1997.



1991 Massachusetts-Maine McIntosh Strain/Rootstock Trial



In 1991, two plantings of three strains of McIntosh (Marshall, Chic-A-Dee, and Rogers Red) and one seedling of McIntosh (Pioneer Mac) on four rootstocks (Mark, M.7 EMLA, M.27 EMLA, and M.26 EMLA) were established, one at the University of Massachusetts Horticultural Research Center in Belchertown and one at the University of Maine Highmoor Farm in Monmouth. Each planting was a randomized-complete-block/split-plot design with seven replications. Scion represented the whole plot, and rootstock was the split plot. This report includes only data from the Massachusetts planting.

Rootstock, scion, and the interaction of rootstock and scion affected TCA, yield per tree in 1997, and yield per tree cumulatively (1993-97) (Table 10). Over all scions, M.7 EMLA resulted in the largest trees, followed by M.26 EMLA, Mark, and M.27 EMLA. Greatest yields per tree in 1997 were harvested from trees on M.26 EMLA, followed by trees on Mark, M.7 EMLA, and M.27 EMLA. Cumulatively, M.26 EMLA and Mark resulted in the greatest yields per tree, followed by M.7 EMLA and M.27 EMLA. Over all rootstocks, Pioneer Mac and Marshall McIntosh were significantly larger than Chic-A-Dee McIntosh, and Rogers Red McIntosh was intermediate. Pioneer Mac yielded the most in 1997, followed by Marshall McIntosh, Chic-A-Dee McIntosh, and Rogers Red McIntosh. Cumulatively, Pioneer Mac yielded more than all of the other scions.

Table 10 also presents, as a view of the significant interactions, separations of rootstock within each scion. Figure 2 shows TCA as affected by the interaction of scion and rootstock. The significant deviation from the overall relationship among rootstocks was seen with Marshall as the scion. Trees on M.26 EMLA and those on M.7 EMLA had similar TCA; whereas, for all other scions, trees on M.7 EMLA were larger than those on M.26 EMLA. Figure 3 shows cumulative yield per tree as affected by the interaction of scion and rootstock. With Marshall McIntosh as the scion, trees on M.7 EMLA yielded significantly less than trees on M.26 EMLA; whereas, they yielded similarly for all other scions. Additionally, Rogers Red McIntosh trees on Mark yielded significantly more than those on M.26 EMLA, and these two rootstock resulted in similar yields for all other scions.

Yield efficiency in 1997 was affected by rootstock but not scion or the interaction of the two (Table 11). M.27 EMLA resulted in the most efficient trees, followed by Mark, M.26 EMLA, and M.7 EMLA. Cumulatively (1993-97), M.27 EMLA and Mark resulted in the most efficient trees, followed by M.26 EMLA and M.7 EMLA. Cumulatively, Chic-A-Dee McIntosh and Pioneer Mac were more efficient than Marshall McIntosh, and Rogers Red McIntosh was intermediate.

Fruit weight in 1997 was not affected by rootstock, but was affected by scion (Table 11). Chic-A-Dee McIntosh produced the largest fruit, followed by Rogers Red McIntosh, Marshall McIntosh, and Pioneer Mac.

Fruit characteristics in 1997 were not affected by the interaction of rootstock and scion; however, scion alone and rootstock alone affected a number of properties (Table 12). Specifically, Pioneer Mac had the lowest soluble solids concentration and lowest flesh firmness. The three other scions were similar for soluble solids and flesh firmness. Scion did not affect starch index value, internal ethylene concentration, or date when the average of internal ethylene concentration reached 1 ppm (log ppm = 0). M.27 EMLA resulted in the highest soluble solids concentration, followed by Mark, M.26 EMLA, and M.7 EMLA. Rootstock did not affect flesh firmness or starch index value. M.26 EMLA resulted in significantly higher internal ethylene concentration than did Mark and M.27 EMLA, and M.7 EMLA resulted in an intermediate concentration. Fruit from trees on M.26 EMLA reached an average internal concentration of 1 ppm (log ppm = 0) first, followed by those from trees on Mark, M.7 EMLA, and M.27 EMLA.

To date, no consistent patterns of fruit ripening effects have occurred in this trial.



1995 Massachusetts-Maine-Nova Scotia Scion/Rootstock Trial

In 1995, a trial was established at three locations (Belchertown, MA, Monmouth, ME, and Kentville, NS) including Rogers Red McIntosh, Cortland, Macoun, and Pioneer Mac on 12 different rootstocks. The experiment was a randomized-complete-block/split-plot design at each site, with scion as the whole plot and rootstock as the split plot. Each site included seven replications. Only Massachusetts data are presented in this report.

Scion cultivar and rootstock did not interact to affect TCA, yield per tree, yield efficiency, or fruit size in 1997 (Table 13). Scion cultivar overall did not affect TCA. McIntosh and Pioneer Mac yielded the most in 1997, followed by Macoun and Cortland. McIntosh, Macoun, and Pioneer Mac were significantly more yield efficient than Cortland. Cortland resulted in the largest fruit, followed by Macoun, McIntosh, and Pioneer Mac.

Over all scion cultivars, trees on Mark were the largest at the end of the 1997 growing season, and those on B.491, P.22, B.146, and P.16 were the smallest (Table 13). Mark also resulted in trees with the greatest yield, and B.146 resulted in trees with the lowest yield. The most yield efficient trees were on P.16, B.491, and P.22, and the least efficient were on Mark, M.9, and V.1. Rootstock did not affect fruit weight in 1997.



1995 Massachusetts-New Brunswick-Pennsylvania Ginger Gold Rootstock Trial

In 1995 a trial was established in Belchertown, MA, University Park, PA, and Bouctouche, NB including Ginger Gold on 10 rootstocks. The experiment was a randomized-complete-block design with 10 replications at each site. Only Massachusetts data are reported here. In 1997, rootstock affected TCA and yield per tree, but did not affect yield efficiency or fruit weight (Table 14). At the end of the 1997 growing season, trees on Mark were the largest and those on P.16, V.3, B.491, and B.469 were the smallest. Trees on Mark yielded significantly more per tree in 1997 than trees on any other rootstock, and there were no significant differences among trees on the other rootstocks.



1995 Liberty Rootstock Trial

A trial was established in 1995 at the University of Massachusetts Horticultural Research Center, including Liberty on six Cornell-Geneva selections in comparison with Liberty on M.9 EMLA. The experiment was a randomized-complete-block design with eight replications. In 1997, rootstock affected TCA and yield efficiency but did not affect yield per tree or fruit weight (Table 15). Specifically, the largest trees were on CG-159. All other trees were similar in size. Trees on CG-995, M.9 EMLA, CG-29, and CG-210 were significantly more yield efficient than trees on CG-159. Trees on CG-214 and CG-710 were intermediate in efficiency.



1996 McIntosh Rootstock Trial

In 1996, a trial was established at the University of Massachusetts Horticultural Research Center including Rogers Red McIntosh on V.1, V.2, V.3, V.4, V.7, and M.26 EMLA. The experiment was a randomized-complete-block design with seven replications. After the second growing season, trees on V.4 had the largest TCA, followed by those on V.7 (Table 16). Trees on V.1, V.2, V.3, and M.26 EMLA were the smallest and similar in size.



USEFULNESS OF FINDINGS



We have defined further the characteristics of several rootstocks grown under Massachusetts conditions with McIntosh, Liberty, Golden Delicious, Jonagold, Empire, Rome, Pioneer Mac, Gala, Ginger Gold, Cortland, and Macoun as apple scion cultivars and Redhaven as a peach scion cultivar. Several rootstocks in the older plantings show great promise for potential commercial adoption. B.9, particularly, is ready for significant grower trial.

In addition to the economic benefits associated with the greater yield efficiency and fruit size of trees on some of these dwarfing rootstocks, significant benefits are realized by growers in Massachusetts selling using pick-your-own techniques. These fully dwarf trees seem particularly suited to pick-your-own marketing, providing for significantly less loss due to fruit drop and poor quality.



WORK PLANNED FOR 1998



All existing plantings will be maintained in 1998. Further, sixteen sites will be selected throughout New England for a 1998 rootstock trial comparing M.9 EMLA, B.9, P.2, and O.3 with Pioneer Mac as the scion cultivar. Each site will be a commercial orchard and will include 10 replications in a randomized-complete-block design. The intent of this study is to take some of the most promising rootstocks to a wider range of soil and climatic conditions in the New England Region than is demonstrated at the university-based research farms. The trial will be coordinated by Maine and Massachusetts. Further, two sites will be selected in Massachusetts for a 1988 trial including Honeycrisp, Fortune, and Cortland in all combinations on M.9 RN19, M.9 RN29, M.9 RN8, M.9 NAKBT337, B.9 V.1, V.3, and M.26 EMLA.



PUBLICATIONS



Refereed Journals

Published articles

Autio, W. R., D. W. Greene, and W. J. Lord. 1996. Performance of 'McIntosh' apple trees on seven rootstocks over 10 years and a comparison of methods of productivity assessment. HortScience 31:1160-1163.

Accepted articles

Autio, W. R., J. R. Schupp, D. C. Ferree, R. Glavin, and D. L. Mulcahy. 1997. Application of RAPDs to DNA extracted from apple rootstocks. HortScience 32: in press.



Non-refereed Publications

Proceedings

Autio, W. R. 1996. The 1994 NC-140 Apple Rootstock Trial in Massachusetts. Proc. New England Fruit Meetings 102:96-97.

Autio, W. R. 1996. The 1994 NC-140 Peach Rootstock Trial in Massachusetts. Proc. New England Fruit Meetings 102:98.

Autio, W. R., J. L. Anderson, J. A. Barden, G. R. Brown, P. A. Domoto, D. C. Ferree, a. Gaus, R. L. Granger, R. A. Hayden, F. Morrison, C. A. Mullins, S. C. Myers, R. L. Perry, C. R. Rom, J. R. Schupp, and L. D. Tukey. 1997. Apple rootstock and scion cultivar interact to affect tree performance in the 1990 NC-140 Cultivar/Rootstock Trial. Compact Fruit Tree 30: in press.

Periodicals

Autio, W. R. 1997. An update on the 1994 NC-140 Apple Rootstock Trial. Fruit Notes 62(2):17-19.

Autio, W. R. 1997. An update on the 1994 NC-140 Peach Rootstock Trial. Fruit Notes 62(2): 20-22.

Extension Bulletins

Autio, W. R. 1997. Update on rootstock research in Massachusetts. University of Massachusetts Extension Factsheet F-123 (10 pp).



Table 1. Trunk cross-sectional area and yield in 1997 of trees in the Massachusetts planting of the 1990 NC-140 Cultivar/Rootstock Trial. All values are least-squares means adjusted for missing subclasses.z
Golden
Rootstock Delicious Jonagold Empire Rome Average
Trunk cross-sectional area (cm2)
M.9 EMLA 27.1 a 27.1 b 27.0 bc 45.3 a 31.8 bc
B.9 28.0 a 33.6 b 25.7 bc 31.2 b 29.6 c
Mark 27.0 a 26.0 b 15.8 c 40.5 ab 26.8 c
0.3 36.0 a 33.8 b 44.7 a 38.9 b
M.26 EMLA 36.8 a 57.5 a 47.9 a 46.0 a 47.1 a
Average 31.1 b 37.0 a 30.1 b 41.1 a
Yield per tree (kg, 1997)
M.9 EMLA 19 21 22 32 23 ab
B.9 21 22 15 23 20 bc
Mark 18 14 10 30 17 c
0.3 24 21 31 25 a
M.26 EMLA 23 29 20 29 25 a
Average 21 bc 22 b 17 c 28 a
Cumulative yield per tree (kg, 1992-97)
M.9 EMLA 93 b 98 b 110 a 149 a 110 ab
B.9 99 b 102 b 79 ab 112 b 98 b
Mark 104 b 94 b 63 b 138 ab 98 b
0.3 133 a 102 a 140 ab 126 a
M.26 EMLA 102 b 134 a 78 ab 135 ab 112 ab
Average 107 b 111 b 84 c 134 a
z Rootstock means within cutivar, overall rootstock means, and overall cultivar means separated by Duncan's New Multiple Range Test (P = 0.05).


Table 2. Yield efficiency and fruit weight in 1997 of trees in the Massachusetts planting of the 1990 NC-140 Cultivar/Rootstock Trial. All values are least-squares means adjusted for missing subclasses and additionally for crop load in the case of fruit weight.z
Yield efficiency (kg/cm2 TCA) Fruit
Cultivar or Cumulative weight
Rootstock 1997 (1992-97) (g)
Golden Delicious 0.70 a 3.54 a 196 c
Jonagold 0.63 a 3.18 a 226 b
Empire 0.60 a 3.15 a 166 d
Rome 0.70 a 3.33 a 249 a
M.9 EMLA 0.72 a 3.50 a 213 a
B.9 0.69 a 3.40 a 206 a
Mark 0.64 a 3.80 a 202 a
0.3 0.69 a 3.35 a 210 a
M.26 EMLA 0.55 b 2.45 b 215 a
z Rootstock means and cultivar means separated by Duncan's New Multiple Range Test (P = 0.05).


Table 3. Trunk cross-sectional area, yield, yield efficiency, and fruit weight in 1997 of Gala trees on several rootstocks in the Massachusetts planting of the 1994 NC-140 Apple Rootstock Trial.z
Yield efficiency
Trunk cross- Yield per tree (kg) (kg/cm2 TCA) Fruit
sectional Cumulative Cumulative weight
Rootstock area (cm2) 1997 (1996-97) 1997 (1996-97) (g)
M.9 EMLA 19.6 de 2.8 ef 5.1 defg 0.18 d 0.31 g 161 bc
M.26 EMLA 26.8 ab 5.7 cdef 6.7 cdefg 0.23 d 0.27 g 164 bc
M.27 EMLA 5.7 g 2.0 f 2.5 g 0.33 cd 0.43 defg 143 bc
M.9 RN29 23.9 bc 3.8 ef 6.4 cdefg 0.17 d 0.27 g 170 bc
M.9 Pajam 1 22.1 cd 5.1 cdef 7.9 cdef 0.23 d 0.37 fg 150 bc
M.9 Pajam 2 27.4 ab 5.7 cdef 9.8 cd 0.21 d 0.37 fg 196 b
B.9 15.4 e 7.8 bcd 9.6 cde 0.54 ab 0.69 bcde 149 bc
B.491 7.6 fg 4.1 def 5.3 defg 0.55 ab 0.70 bcd 159 bc
0.3 18.3 de 8.2 bc 10.7 bc 0.45 bc 0.60 cdef 148 bc
V.1 29.2 a 10.0 ab 14.4 ab 0.34 cd 0.49 defg 159 bc
P.2 19.1 de 4.2 def 4.4 fg 0.21 d 0.22 g 151 bc
P.16 9.4 fg 5.2 cdef 6.1 cdefg 0.54 ab 0.64 bcdef 145 bc
Mark 17.6 e 10.4 ab 14.7 ab 0.58 ab 0.84 abc 121 c
P.22 5.3 g 3.3 ef 4.8 efg 0.62 ab 0.91 ab 134 bc
B.469 10.4 f 6.4 cde 8.6 cdef 0.62 ab 0.83 abc 128 bc
M.9 Fleuren 56 15.2 e 3.7 ef 5.0 defg 0.27 cd 0.37 fg 173 bc
M.9 NAKBT337 17.1 e 5.6 cdef 7.3 cdefg 0.31 cd 0.42 efg 165 bc
Delicious/M.26 EMLA 16.8 e 3.8 ef 4.4 fg 0.23 d 0.28 g 290 a
Liberty/M.9 NAKBT337 16.6 e 11.2 ab 17.1 a 0.68 a 1.05 a 183 bc
Fuji/Mark 17.7 e 12.3 a 16.2 a 0.70 a 0.92 ab 147 bc
z Mean separation within columns by Duncan's New Multiple Range Test (P = 0.05).


Table 4. Bloom in 1997 of Gala trees on several rootstocks in the Massachusetts planting of the 1994 NC-140 Apple Rootstock Trial.z
Bloom density (clusters/cm2 LCA)
Rootstock Spur Lateral Total
M.9 EMLA 9.0 gh 13.6 ab 22.6 c
M.26 EMLA 11.2 cdefg 14.8 ab 26.0 bc
M.27 EMLA 12.7 cdef 13.0 ab 25.7 bc
M.9 RN29 11.1 defg 15.0 ab 26.0 bc
M.9 Pajam 1 10.7 efg 12.0 ab 22.7 c
M.9 Pajam 2 10.6 efg 14.0 ab 24.7 bc
B.9 12.2 cdef 17.0 a 29.2 ab
B.491 13.9 cde 15.7 a 29.6 ab
0.3 12.9 cde 16.0 a 28.8 ab
V.1 11.4 cdefg 12.4 ab 23.8 bc
P.2 9.5 fgh 12.4 ab 21.9 c
P.16 14.3 abc 13.0 ab 27.3 abc
Mark 16.4 ab 11.6 ab 28.0 abc
P.22 16.1 ab 13.2 ab 29.3 ab
B.469 17.1 a 15.4 a 32.5 a
M.9 Fleuren 56 11.3 cdefg 12.3 ab 23.6 bc
M.9 NAKBT337 12.5 cdef 16.7 a 29.2 ab
Delicious/M.26 EMLA 7.2 h 4.0 c 11.2 e
Liberty/M.9 NAKBT337 9.0 gh 13.2 ab 22.1 c
Fuji/Mark 6.9 h 9.8 b 16.7 d
z Mean separation within columns by Duncan's New Multiple Range Test (P = 0.05).


Table 5. Fruit set in 1997 of Gala trees on several rootstocks in the Massachusetts planting of the 1994 NC-140 Apple Rootstock Trial.z
Fruit set Fruit set Lateral
(number/cm2 LCA) (number/100 blossom clusters) fruit set
Rootstock Spur Lateral Total Spur Lateral Total (% of total)
M.9 EMLA 0.5 g 0.4 f 0.9 f 5.8 h 3.4 de 4.1 g 38 abcd
M.26 EMLA 1.0 efg 0.2 f 1.2 f 8.4 fgh 2.3 de 5.1 g 18 cd
M.27 EMLA 1.7 cdefg 0.6 def 2.3 def 13.5 efgh 5.1 de 9.2 efg 25 abcd
M.9 RN29 0.7 g 0.5 ef 1.2 f 5.7 h 4.2 de 4.8 g 48 a
M.9 Pajam 1 0.9 fg 0.5 ef 1.4 ef 7.8 fgh 4.4 de 6.5 efg 34 abcd
M.9 Pajam 2 1.0 efg 0.4 f 1.4 ef 9.3 fgh 3.0 de 5.8 g 26 abcd
B.9 2.4 cde 1.5 abcd 4.0 cd 19.2 def 8.7 cde 13.4 de 35 abcd
B.491 2.2 cdef 0.9 cdef 3.1 de 14.1 efgh 6.1 de 10.3 efg 27 abcd
0.3 1.9 cdefg 0.7 def 2.6 def 14.6 efgh 4.0 de 8.5 efg 25 abcd
V.1 1.7 cdefg 0.6 def 2.4 def 15.2 efgh 5.6 de 9.9 efg 23 abcd
P.2 0.8 g 0.2 f 0.9 f 7.4 gh 1.2 e 4.1 g 15 d
P.16 2.4 cd 1.4 bcde 3.8 cd 17.8 efg 9.1 cde 13.2 def 39 abcd
Mark 6.3 a 1.2 bcdef 7.4 a 37.4 b 17.1 bc 26.2 b 17 cd
P.22 4.0 b 1.9 ab 5.9 ab 28.9 bcd 18.4 abc 21.5 bc 33 abcd
B.469 3.9 b 1.7 abc 5.6 b 23.1 cde 12.3 bcd 17.0 cd 27 abcd
M.9 Fleuren 56 1.2 defg 0.2 f 1.5 ef 11.5 fgh 1.7 de 6.2 fg 20 bcd
M.9 NAKBT337 1.4 defg 0.9 cdef 2.2 def 12.4 efgh 5.9 de 7.3 efg 43 abc
Delicious/M.26 EMLA 0.6 g 0.3 f 0.9 f 6.7 gh 9.6 cde 6.9 efg 33 abcd
Liberty/M.9 NAKBT337 2.8 bc 2.5 a 5.3 bc 31.6 bc 19.9 ab 24.2 b 46 ab
Fuji/Mark 3.8 b 2.0 ab 5.9 ab 55.7 a 27.1 a 36.1 a 36 abcd
z Mean separation within columns by Duncan's New Multiple Range Test (P = 0.05).


Table 6. Trunk cross-sectional area, date of 90% bloom, date of 10% fruit maturity, and extent of borer damage of Redhaven peach trees planted in Massachusetts as part of the 1994 NC-140 Peach Rootstock Trial. All values are least-squares means adjusted for missing subclasses.z
Trunk cross- Date of Date of 10% Borer
sectional area 90% bloom fruit maturity rating
Rootstock (cm2) (Julian) (Julian) (0-4)y
Lovell 63.2 a 136 a 227 b 1.1 ab
Bailey 52.8 abc 136 a 226 b 1.9 a
TN 281-1 56.2 abc 135 a 227 b 1.4 a
Stark's Redleaf 47.7 abcd 135 a 226 b 1.8 a
GF 305 47.7 abcd 136 a 226 b 1.9 a
Higama 57.2 ab 137 a 227 b 1.7 a
Montclar 56.6 ab 136 a 227 b 1.0 ab
Rubira 37.7 d 134 a 227 b 1.3 a
Ishtara 24.9 e 133 a 227 b 0.1 b
H7338019 40.0 cd 136 a 226 b 1.5 a
BY520-8 45.0 bcd 136 a 227 b 1.5 a
Guardian 63.1 a 134 a 227 b 1.3 a
TaTao 5/Lovell 44.7 bcd 136 a 230 a 1.0 ab
z Mean separation within columns by Duncan's New Multiple Range Test (P = 0.05).
y Borer rating: 0 = no evidence of borer damage, 4 = extensive borer damage.


Table 7. Fruit weight, yield, and yield efficiency of Redhaven peach trees planted in Massachusetts as part of the 1994 NC-140 Peach Rootstock Trial. All values are least-squares means adjusted for missing subclasses.z
Fruit Yield per tree (kg) Yield efficiency (kg/cm2 TCA)
weight Cumulative Cumulative
Rootstock (g) 1997 (1996-97) 1997 (1996-97)
Lovell 241 a 14 a 23 a 0.23 bc 0.38 bcd
Bailey 253 a 13 a 26 a 0.25 bc 0.52 bcd
TN281-1 237 a 13 a 21 a 0.24 bc 0.39 bcd
Stark's Redleaf 257 a 12 a 25 a 0.26 bc 0.52 bcd
GF305 244 a 14 a 26 a 0.30 bc 0.57 bc
Higama 225 a 14 a 29 a 0.24 bc 0.51 bcd
Montclar 238 a 8 a 17 a 0.15 c 0.32 d
Rubira 248 a 14 a 22 a 0.37 b 0.61 b
Ishtara 244 a 17 a 22 a 0.68 a 0.89 a
H7338019 252 a 13 a 20 a 0.31 bc 0.49 bcd
BY520-8 221 a 9 a 18 a 0.19 bc 0.38 cd
Guardian 225 a 16 a 27 a 0.26 bc 0.44 bcd
TaTao5/Lovell 227 a 12 a 20 a 0.25 bc 0.43 bcd
z Mean separation within columns by Duncan's New Multiple Range Test (P = 0.05).


Table 8. Characteristics in 1997 of Liberty trees on three rootstocks planted in 1990.z
Yield efficiency
Trunk cross- Yield per tree (kg) (kg/cm2 TCA) Fruit
sectional area Cumulative Cumulative weight
Rootstock (cm2) 1997 (1992-97) 1997 (1992-97) (g)
M.7 109.2 a 14 b 114 b 0.13 b 1.04 b 162 a
M.9 22.6 c 18 ab 92 c 0.86 a 4.24 a 146 b
M.26 37.1 b 23 a 135 a 0.65 a 3.88 a 148 b
z Mean separation within column by Duncan's New Multiple Range Test (P = 0.05).


Table 9. Characteristics in 1997 of Marshall McIntosh trees on three rootstocks planted in 1990.z
Yield efficiency
Trunk cross- Yield per tree (kg) (kg/cm2 TCA) Fruit
sectional area Cumulative Cumulative weight
Rootstock (cm2) 1997 (1992-97) 1997 (1992-97) (g)
M.9 EMLA 30.5 b 15 a 84 a 0.50 b 2.81 a 152 b
B.9 22.0 c 16 a 71 a 0.72 a 3.28 a 151 b
M.26 EMLA 53.0 a 16 a 82 a 0.30 c 1.60 b 172 a
z Mean separation within column by Duncan's New Multiple Range Test (P = 0.05).


Table 10. Trunk cross-sectional area and yield in 1997 of three strains of McIntosh and one McIntosh seedling on four rootstocks planted in 1991.z
Pioneer Marshall Chic-A-Dee Rogers Red
Rootstock Mac McIntosh McIntosh McIntosh Average

Trunk cross-sectional area (cm2)

Mark 30.4 c 30.7 b 26.3 b 37.2 a 31.2 c
M.7 EMLA 72.8 a 49.3 a 46.7 a 47.8 a 54.2 a
M.27 EMLA 10.9 d 9.8 c 7.2 c 7.9 b 9.0 d
M.26 EMLA 41.8 b 54.3 a 29.1 b 37.0 a 40.6 b
Average 39.0 a 36.0 a 27.3 b 32.4 ab
Yield per tree (kg, 1997)
Mark 23 b 26 a 18 a 20 a 22 ab
M.7 EMLA 24 ab 14 b 19 a 18 a 19 b
M.27 EMLA 10 c 9 b 8 b 9 b 9 c
M.26 EMLA 32 a 31 a 20 a 12 ab 24 a
Average 23 a 20 ab 16 bc 15 c
Cumulative yield per tree (kg, 1993-97)
Mark 91 a 76 a 59 a 84 a 77 a
M.7 EMLA 93 a 44 b 67 a 59 b 66 b
M.27 EMLA 32 b 20 c 23 b 24 c 25 c
M.26 EMLA 106 a 93 a 70 a 65 b 83 a
Average 80 a 58 b 55 b 58 b
z Mean separation of rootstock within cultivar, rootstock overall, and cultivar overall by Duncan's New Multiple Range Test (P = 0.05).



Table 11. Yield efficiency and fruit weight in 1997 of three strains of McIntosh and one McIntosh seedling on four rootstocks planted in 1991.z
Yield efficiency (kg/cm2 TCA) Fruit
Cumulative weight
Rootstock/Cultivar 1997 (1993-97) (g)
Mark 0.77 b 2.60 a 157 a
M.7 EMLA 0.35 c 1.19 c 157 a
M.27 EMLA 1.04 a 2.81 a 146 a
M.26 EMLA 0.63 b 2.21 b 156 a
Pioneer Mac 0.74 a 2.48 a 145 c
Marshall McIntosh 0.70 a 1.84 b 151 bc
Chic-A-Dee McIntosh 0.76 a 2.40 a 161 a
Rogers Red McIntosh 0.59 a 2.09 ab 157 ab
z Mean separation within rootstock and within cultivars by Duncan's New Multiple Range Test (P = 0.05).
Table 12. Characteristics in 1997 of fruit from three strains of McIntosh and one McIntosh seedling on four rootstocks planted in 1991. Flesh firmness values are least-squares means adjusted for fruit weight.z
Internal C2H4 Date
Soluble Flesh Starch concentration average
solids firmness index 17 Sept. 1997 log ppm
Rootstock/Cultivar (%) (N) valuey (ppm) C2H4 = 0
Mark 11.4 b 70.3 a 4.6 a 0.3 b 23 Sept. b
M.7 EMLA 11.1 c 70.8 a 4.5 a 0.5 ab 21 Sept. bc
M.27 EMLA 11.7 a 69.8 a 4.1 a 0.2 b 27 Sept. a
M.26 EMLA 11.3 bc 70.3 a 4.6 a 1.0 a 19 Sept. c
Pioneer Mac 10.8 b 67.2 b 4.9 a 0.4 a 23 Sept. a
Marshall McIntosh 11.7 a 71.1 a 4.3 a 0.5 a 21 Sept. a
Chic-A-Dee McIntosh 11.3 a 71.1 a 4.3 a 0.3 a 24 Sept. a
Rogers Red McIntosh 11.6 a 71.6 a 4.3 a 0.4 a 21 Sept. a
Z Mean separation within rootstock and within cultivar by Duncan's New Multiple Range Test (P = 0.05).
y Starch index: 1 = dense starch staining, very immature; 9 = no starch staining, very overmature.


Table 13. Trunk cross-sectional area, yield per tree, yield efficiency, and fruit weight in 1997 of Cortland, Rogers Red McIntosh, Macoun, and Pioneer Mac trees on several rootstocks planted in 1995. All values are least-squares adjusted for missing subclasses.z
Trunk cross- Yield per Yield Fruit
sectional area tree efficiency weight
Cultivar/Rootstock (cm2) (kg) (kg/cm2 TCA) (g)
Cortland 4.7 a 0.7 c 0.19 b 218 a
Rogers Red McIntosh 4.7 a 1.9 a 0.45 a 153 c
Macoun 4.3 a 1.4 b 0.40 a 192 b
Pioneer Mac 4.8 a 1.9 a 0.46 a 157 c
B.491 2.3 e 1.4 bc 0.58 ab 185 a
B.146 1.8 e 0.4 d 0.31 bcd 162 a
P.2 5.0 c 1.9 b 0.40 abcd 180 a
P.22 2.1 e 1.3 bcd 0.66 a 177 a
V.1 7.0 b 1.1 cd 0.15 d 178 a
V.3 4.9 c 2.0 b 0.38 bcd 189 a
B.469 3.4 d 1.1 cd 0.31 cd 180 a
P.16 1.8 e 1.1 cd 0.54 abc 170 a
B.9 5.7 c 1.8 bc 0.36 bcd 182 a
M.9 5.2 c 1.3 bcd 0.26 d 193 a
M.9 NAKBT337 5.2 c 1.5 bc 0.29 cd 179 a
Mark 10.6 a 2.9 a 0.26 d 187 a
z Mean separation within cultivars and within rootstocks by Duncan's New Multiple Range Test (P = 0.05).


Table 14. Trunk cross-sectional area, yield per tree, and yield efficiency in 1997 of Ginger Gold trees on various rootstocks planted in 1995.z
Trunk cross- Yield per Yield Fruit
sectional area tree efficiency weight
Rootstock (cm2) (kg) (kg/cm2 TCA) (g)
B.491 1.6 d 0.3 b 0.18 a 224 a
P.2 4.4 c 0.2 b 0.06 a 207 a
P.22 2.6 d 0.2 b 0.06 a 189 a
V.1 5.9 b 0.4 b 0.05 a 236 a
V.3 1.7 d 0.1 b 0.04 a 160 a
B.469 1.5 d 0.2 b 0.13 a 172 a
P.16 1.8 d 0.2 b 0.11 a 189 a
B.9 5.0 bc 0.3 b 0.06 a 241 a
M.9NAKBT337 4.6 bc 0.5 b 0.13 a 240 a
Mark 9.3 a 0.9 a 0.09 a 249 a
z Mean separation within columns by Duncan's New Multiple Range Test (P = 0.05).


Table 15. Trunk cross-sectional area, yield, yield efficiency, and fruit size in 1997 of Liberty trees on various rootstocks planted in 1995. All means are least-squares means adjusted for missing subclasses.z
Trunk cross- Yield Yield Fruit
sectional area per tree efficiency weight
Rootstock (cm2) (kg) (kg/cm2 TCA) (g)
M.9 EMLA 4.2 b 1.3 a 0.33 a 178 a
CG-29 4.6 b 1.7 a 0.33 a 167 a
CG-159 13.1 a 0.0 a 0.01 b
CG-214 4.0 b 0.7 a 0.17 ab 136 a
CG-210 1.9 b 1.6 a 0.42 a 177 a
CG-710 3.5 b 0.7 a 0.15 ab 178 a
CG-995 4.6 b 1.1 a 0.26 a 168 a
z Mean separation within columns by Duncan's New Multiple Range Test (P = 0.05).


Table 16. Trunk cross-sectional area in 1997 of Rogers Red McIntosh Trees on various rootstocks planted in 1996.z
Trunk
cross-sectional area
Rootstock (cm2)
V.1 2.0 c
V.2 2.3 c
V.3 2.2 c
V.4 4.9 a
V.7 3.0 b
M.26 EMLA 2.2 c
z Mean separation within columns by Duncan's New Multiple Range Test (P = 0.05).