In 1990, a trial was established at 17 locations in the United States and Canada including the scions `Golden Delicious', `Jonagold', `Empire', and `Rome” and the rootstocks M.9 EMLA, B.9, Mark, O.3, and M.26 EMLA. In 1994, trees on M.26 EMLA were the largest and trees on B.9 and those on Mark were the smallest, regardless of scion. Trees on M.9 EMLA were intermediate. `Golden Delicious' and `Empire” trees on O.3 were larger than those on M.9 EMLA. `Jonagold' and `Rome' trees on O.3 were similar in size to those on M.9 EMLA. With all scions, B.9 and Mark resulted in the lowest cumulative yields. With `Jonagold', `Empire', or `Rome' as the scion, O.3, M.26 EMLA, and M.9 EMLA resulted in the greatest and similar yields. With `Golden Delicious' as the scion, however, trees on M.9 EMLA yielded only as much as those on B.9 or Mark. Trees on B.9 and those on Mark were the most yield-efficient, regardless of scion. `Golden Delicious' and `Rome' trees on O.3 were similar to those on B.9 and those on Mark, but `Jonagold' and `Empire' trees on O.3 were less efficient than those on B.9 or on Mark. Overall, M.26 EMLA resulted in the lowest efficiency; however, M.9 EMLA resulted in more efficient trees only with `Empire' as the scion. Participants include: J.L. Anderson (Utah), W.R. Autio (Mass.), J.A. Barden (Va.), G.R. Brown (Ky.), P.A. Domoto (Iowa), D.C. Ferree (Ohio), A. Gaus (Colo.), R.L. Granger (Quebec), R.A. Hayden (Ind.), F. Morrison (Kan.), C.A. Mullins (Tenn.), S.C. Myers (Ga.), R.L. Perry (Mich.), C.R. Rom (Ark.), J.R. Schupp (Maine), and L.D. Tukey (Pa.).
Wesley R. Autio
The effects of rootstock on `Delicious' apple maturity, quality, size, mineral composition, and storability were studied over a 4-year period. Removing the effects of crop load and crop load within year by analysis of covariance produced results suggesting that M.27 EMLA and Ott.3 advanced fruit maturity and that M.7 EMLA delayed fruit maturity. M.9, MAC 9, OAR 1, M.9 EMLA, and M.26 EMLA either were inconsistent in their effect on maturity or consistently resulted in an intermediate maturity. Size, after adjusting for the effects of crop load and crop load within year, was consistently high for fruit from trees on M.9 EMLA, and lowest for fruit from trees on OAR 1. After adjusting for fruit size, fruit from trees on MAC 9 generally had high Ca contents, and fruit from trees on OAR 1 had low Ca contents. The effect of rootstock on storability appeared to be secondary and related to maturity and Ca level.
Wesley R. Autio
`Summerland Red McIntosh' apple trees propagated on M.9/A.2,O.3, M.7 EMLA, M.26 EMLA, M.7A. OAR1, or Mark rootstocks were planted in 1985 in a randomized complete block design with seven replications. Fruit ripening and quality were assessed in 1988-93. Internal ethylene concentrations were measured weekly throughout each harvest season. Once each season, fruit weight, starch-index value, soluble solids concentration, flesh firmness, and surface ted color were assessed on a sample of fruit from each tree. Size was smallest for fruit from trees on OAR1 or Mark, after accounting for the effects of crop load with analysis of covariance. Surface ted color was greatest for fruit from trees on Mark and least for fruit from trees on M.7 EMLA. Ripening was variable, but generally, fruit from trees on 0.3 ripened first, and fruit from trees on M.7 EMLA or M.7A ripened last. Crop load impacted ripening, but its effects were removed with analysis of covariance.
Wesley R. Autio
In 1990, trials were established at 13 sites including `Golden Delicious', `Jonagold', `Empire', and `Rome' apple cultivars in all combinations on M.9 EMLA, B.9, Mark, O.3, and M.26 EMLA rootstocks. After 10 growing seasons, rootstock and cultivar interacted significantly to affect trunk cross-sectional area and yield efficiency but not yield per tree or survival. Generally, trunk cross-sectional area was greatest for M.26 EMLA, followed by O.3, M.9 EMLA, B.9, and Mark. However, differences between B.9 and Mark and between M.9 EMLA and O.3 varied with cultivar. B.9 was 34% to 46% larger than Mark with `Golden Delicious' and `Empire,' but they were similar for `Jonagold' and `Rome.' O.3 was 27% larger than M.9 EMLA with `Golden Delicious' and `Empire,' they were similar for `Rome', and O.3 was 12% smaller than M.9 EMLA with `Jonagold'. M.26 EMLA resulted in the greatest cumulative yield per tree, followed by O.3, M.9 EMLA, B.9, and Mark. Generally, cumulative yield efficiency (1992–99) was greatest B.9 and Mark and least for M.26 EMLA. M.9 EMLA and O.3 were similar and intermediately efficient. However, differences between B.9 and Mark and between M.9 EMLA and O.3 varied with cultivar. M.9 EMLA and O.3 were similarly efficient with `Golden Delicious', `Jonagold', and `Rome,' but M.9 EMLA was 11% more efficient than O.3 with `Empire'. B.9 and Mark were similarly efficient with `Golden Delicious' and `Jonagold', but Mark was 15% more efficient and 25% less efficient than B.9 trees with `Empire' and `Rome', respectively. Site played an important role, but survival was best for B.9 and poorest for O.3. Cooperators included: J.L. Anderson, W. Autio, J. Barden, G. Brown, R. Crassweller, P. Domoto, A. Erb, D. Ferree, A. Gaus, R. Hayden, P. Hirst, F. Morrison, C. Mullins, J. Schupp, and L. Tukey.
Wesley R. Autio
The effects of rootstock on `Delicious' (Malus domestics Borkh.) apple ripening, quality, size, mineral composition, and storability were studied over 4 years. Removal of the effects of crop load by analysis of covariance suggested that M.27 EMLA advanced fruit ripening and that M.7 EMLA delayed fruit ripening. Ott.3, M.9, MAC 9, OAR 1, M.9 EMLA, and M.26 EMLA either were inconsistent in their effects on ripening or consistently-resulted in an intermediate time of ripening. Fruit size consistently was largest from trees on M.9 EMLA and smallest from trees on OAR 1. Fruit from trees on MAC 9 generally had relatively high Ca contents, and fruit from trees on OAR 1 had relatively low Ca concentrations. The effects of rootstock on storability appeared to be related to their effects on maturity arid Ca levels.
Duane W. Greene and Wesley R. Autio
There is a general increase in interest in planting new apple cultivars. Promising new apple cultivars have been identified from around the world and from breeding programs in Arkansas, British Columbia, New York, New Jersey and the PRI Program. Trees were propagated and planted in a cultivar evaluation block at the University of Massachusetts Horticultural Research Center. Fruit assessment consisted of laboratory analysis and visual and sensory evaluation. Fruit were rated and several cultivars were identified as showing extreme promise and being worthy of further evaluation. These apple cultivars include: Sansa, Ginger Gold, Honeycrisp, BC 8M 15-10, BC 17-30, Arlet (Swiss Gourmet), NY 75414-1, NY 429, Golden Supreme and SunCrisp (NJ 55). The strong and weak points of each cultivars will be discussed.
Justine E. Vanden Heuvel and Wesley R. Autio
Anecdotal information has linked cool air temperatures before harvest with increased phenolic production in cranberry; however, there is little information available on the effect of temperature on phenolic production in cranberry fruit. The objective of this study was to determine the effect of air temperature throughout the growing season on the concentration of total anthocyanins, total flavonols, and total phenolics at harvest in fruit from seven ‘Early Black’ bogs in southeastern Massachusetts. Contrary to the anecdotal information available, correlations of temperature to fruit composition indicated that warmer temperatures early in the season (around bloom and fruit set) had the most positive impact on total anthocyanins and total flavonols. Total phenolic concentration in the harvested fruit was impacted by air temperature in the preharvest period; however, that relationship was positive.
Wesley R. Autio and Duane W. Greene
In 1991, experiments were conducted to assess the effects of several growth controlling techniques on tree growth and fruit set, abscision, ripening, and other qualities. The first two experiments assessed the effects of root pruning (4-8 days after petal fall, 1 m from the trunk, 30 cm deep) in commercial orchards. Compared to controls, root pruning reduced fruit abscision from mature `Cortland'/M.7A trees by 70% on 17 Sept. In another orchard, root pruning reduced fruit abscision from mature `McIntosh'/MM.106 trees by 47% on 24 Sept. The third experiment utilized vigorous `Gardiner Delicious'/MM.106 trees. Treatments included root pruning (as described above), trunk scoring (single, complete circle, approximately 40 cm from the soil), trunk ringing (single, complete circle, 1 mm wide, approximately 40 cm from the soil), ethrel spray treatment (500 ppm), and dormant-pruned and unpruned controls. Treatments were applied on 15 May, when terminal growth was 12-15 cm. No treatment affected fruit set. Trunk growth was less for ringed and scored trees than other treatments. Ringing and scoring advanced ripening compared to controls, and ethrel resulted in intermediate ripening. Treatments had no effect on fruit size, flesh firmness, or the development of bitter pit and cork spot. Fruit abscision was least from controls and root-pruned trees. Trees that were treated with ethrel in May had the most rapid abscision rate.
Wesley R. Autio and Joseph F. Costante
Ripening of `Liberty' and `Empire' apples was compared in 1988-90. The internal ethylene of `Liberty' fruit reached 1 ppm approximately 7 to 10 days before `Empire.' `Liberty' and `Empire' fruit both attained acceptable eating quality on approximately 30 Sept. each year. Generally, `Liberty' fruit were firmer and had a higher soluble solids content than `Empire' fruit. Storage properties were compared in 1988 and 1989. In 1988, fruit were harvested at weekly intervals from 20 Sept. to 12 Oct. and kept at 0C for 2.5 months. The firmest fruit of both cultivars were from the 27 Sept. harvest. Fruit of both cultivars harvested on 27 Sept. 1988 retained firmness better when kept at 3.3C, 3% O2, 5% CO2 than when kept at 0C, 3% O2, 2% CO2. Data from 1989 showed that `Liberty' developed large amounts of browncore in controlled atmospheres at either 0C or 3.3C. The incidence of browncore in refrigerated storage declined with later harvests.
Duane W. Greene and Wesley R. Autio
There is a general increase in interest in planting new apple cultivars. The loss of daminozide has provided an additional stimulus for growers in New England to find an alternative to McIntosh. Promising new apple cultivars have been identified from around the world and from breeding programs in Arkansas, British Columbia, New York, New Jersey and the PRI Program. Trees were propagated and planted in a cultivar evaluation block at the University of Massachusetts Horticultural Research Center. In 1992 we evaluated over 80 new cultivars. Fruit assessment consisted of laboratory analysis and visual and sensory evaluation. All cultivar were given an overall rating, and several were identified as being worthy of further evaluation. These apple cultivars include: Arlet, BC 9P 14-32, BC 8M 15-10, BC 17-30, Ginger Gold, Honeycrisp, Kinsei, NJ 55, NY 75414-1, and Sansa.