Apple tree canopy development and photosynthesis as affected by rootstock

1991 ◽  
Vol 69 (2) ◽  
pp. 295-300 ◽  
Author(s):  
Ido Schechter ◽  
D. C. Elfving ◽  
J. T. A. Proctor

Trees of apple (Malus domestica Borkh.) with 'Starkspur Supreme Delicious' as the scion grafted on nine different rootstocks (Ottawa 3, M.7 EMLA, M.9 EMLA, M.26 EMLA, M.27 EMLA, M.9, MAC-9, MAC-24, OAR 1) were studied in their 8th and 9th years. Canopy seasonal development and its light interception followed by fisheye (hemispherical) photography showed that rootstock affected the amount of structural wood, the rate of canopy development, and final leaf area. However, rootstock did not affect the sigmoidal pattern of canopy development. Light interception was linearly correlated with tree dimensions and yield. Leaf net photosynthesis (Pn) of trees on dwarfing rootstocks tended to be lower than Pn rates of trees on more vigorous rootstocks. Rootstock did not affect the scion Pn response to different illumination levels. Shoot leaves, spur leaves on spurs without fruit (S − F), and spur leaves on spurs with fruit (S + F) from trees on M.26 EMLA and OAR 1 showed no differences in Pn rates. However, for both rootstocks, shoot leaves had the highest Pn rate, S + F the lowest, and S − F leaves had intermediate values. Key words: light interception, fisheye photography, leaf type.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1128c-1128
Author(s):  
Ido Schechter ◽  
D.C. Elfving ◽  
J.T.A. Proctor

Mature apple (Malus domestic a Borkh.) trees with “Starkspur Supreme Delicious” as the scion grafted on nine different rootstocks were studied in 1987 and 1988. Canopy seasonal development and its light interception were examined using fisheye (hemispherical) photographs Rootstock affected the amount of structural wood, the rate of canopy development and the final leaf area. However, rootstock did not affect the sigmoidal pattern of canopy development. Photosynthesis (Pn) was measured under field conditions. Shoot leaves, spur leaves on spurs without fruits (S-F), and spur leaves on spurs with fruit (S+F) from trees on M.26 EMLA and OAR 1 showed no differences in Pn rates. However, for both rootstock, shoot leaves had the highest Pn rate, S+F the lowest, and S-F leaves had intermediate values Growth and yield components were assessed by leaf separation into shoot and spur leaves while harvesting them. Rootstock strongly affected the canopy leaf distribution as well as leaf number, dry weight, area, number of spurs and yield PCLC. Yield efficiency was mainly dependent upon spur leaf dry weight. OAR 1 performed uniquely in this study


1982 ◽  
Vol 62 (2) ◽  
pp. 513-518
Author(s):  
B. J. PARLIMAN ◽  
C. STUSHNOFF

Beacon apple tree (Malus domestica Borkh.) variants derived from gamma-irradiated scionwood on Columbia Crab seedling (CC) rootstocks were compared to both standard Beacon/clonal rootstocks, standard Beacon/CC rootstocks and Columbia Crab seedling trees. Stem or root measurements of trees classed as induced spur-type dwarf variants/CC rootstocks had larger bark to xylem ratios than trees from other growth habit classes. Stem and root bark to xylem ratios have the potential to be used as juvenile selection criteria in screening for spur-type dwarf variants in irradiation-exposed apple tree populations.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 463
Author(s):  
Kristina Laužikė ◽  
Nobertas Uselis ◽  
Giedrė Samuolienė

With the growing demand for quality food in the world, there is a new ambition to produce high-quality apples seeking reduced cultivation costs. The aim of this study was to evaluate the influence of agrotechnological tools on the quality of cv. Rubin apples during the harvest. The apple tree (Malus domestica Borkh.) cv. Rubin was grafted on dwarfing rootstocks P60, planted in single rows spaced 1.25 m between trees and 3.5 m between rows. Six agrotechnological tools were used—hand pruning, mechanical pruning, trunk incision, calcium-prohexadione, summer pruning and mechanical pruning one side, changing sides annually. The agrotechnical tools had no significant effect on accumulation of most sugars and elements, malic, folic and succinic acids in the fruits. Mechanical pruning resulted in significant accumulation of phenolic compounds, antioxidants, ascorbic acid, but reduced the amount of glucose compared to hand pruning. However, the trunk incision or spraying with ca-prohexadione together with mechanical pruning had no significant effect on sugar content but resulted in significantly higher amounts of phenols, antioxidants, ascorbic acid, Fe and Mn and reduced starch and citric acid.


Horticulturae ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 89
Author(s):  
Nídia Rosa ◽  
Wim Verjans ◽  
Glória Àvila ◽  
Joaquim Carbó ◽  
Joan Bonany ◽  
...  

Metamitron is an apple (Malus domestica Borkh.) fruit thinner that acts by reducing the photosynthetic capacity of trees. Relative humidity may influence thinning efficacy; however, the broadness of this effect is not yet fully understood. Trials were set in Sint-Truiden (Belgium) in 2018 and Lleida and Girona (Spain) in 2019, using 4-year-old cvs. Braeburn and Elstar trees in Belgium, and 16-year-old cv. Golden Reinders trees in Spain. Four treatments were implemented at the stage of 12–14 mm fruit diameter: (a) CTR—control, trees under natural environmental conditions; (b) HH—high humidity, trees submitted to artificially increased air relative humidity applied for 3 h prior to the beginning of the experiment; (c) MET—trees sprayed with 247.5 mg/L metamitron; (d) MET + HH—trees submitted to the combination of increased humidity (HH) and metamitron (MET) application. In Belgium, metamitron absorption by leaves was greater than in Spain. This might be related to morphological characteristics of the leaves which developed under greater natural relative humidity levels in Belgium than in Spain. Compared to MET alone, ‘Braeburn’ and ‘Elstar’ demonstrated significantly greater metamitron absorption, 59% and 84%, respectively, under MET + HH, accompanied by declines in leaf net photosynthesis (10% and 32%, respectively) and sucrose (31% and 26%, respectively). At harvest, MET + HH treatment reduced yield by 24% and 32% in ‘Braeburn’ and ‘Elstar’, respectively, when compared with MET alone. A large reduction (considered over thinning) in the yield of ‘Elstar’ occurred. In contrast, metamitron absorption by ‘Golden Reinders’ using MET alone was similar to MET + HH; however, there was a slight foliar sugar reduction in the latter treatment. In addition, both treatments enhanced shoot growth and increased fruit abscission with similar improvements in fruit weight and size. In this study, high relative humidity enhanced fruit thinning efficacy under certain circumstances, such as age or genetic predisposal, which left the tree more susceptible to a negative carbohydrate balance. For instance, ‘Braeburn’ and ‘Elstar’ were easier to thin when compared to ‘Golden Reinders’. In addition, this study raises a question that requires further research regarding the impact of HH before and after spraying as well as its effect in combination with higher temperatures.


Sign in / Sign up

Export Citation Format

Share Document