scholarly journals Studies of the Vigor and Productivity of Micropropagated Trees

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 793B-793 ◽  
Author(s):  
C.S. Walsh ◽  
F.J. Allnutt ◽  
G.R Welsh ◽  
R.H. Zimmerman
Keyword(s):  
Tree Size ◽  
Root Pruning ◽  
Propagation Time ◽  
Ex Vitro ◽  
Short Life ◽  
Subsequent Trial ◽  
Management Scheme ◽  
Life Problems ◽  
Control Tree ◽  
Size Controlling

A planting to compare budded apple trees (M7a, Ml11) and tissue-culture-(TC) propagated trees was established in 1985. `Golden Delicious' and `Gala' trees were more productive than other cultivars and appeared better-suited to micropropagation. High cumulative yields per tree were harvested regardless of rootstock. `McIntosh', `Delicious', `Mutsu', and `MacSpur' trees were less precocious and more responsive to size-controlling rootstocks. To control tree size prior to bearing and minimize propagation time, trees were set as containerized transplants in a subsequent trial begun in 1986. Small containerized trees were set directly into the orchard. Setting trees in this manner has restricted tree size without delaying bearing. `Oregon Spur II' trees and `Empire' trees are now about 4 m tall. Trees have wide branch angles and numerous spurs. To further control tree size, trees were root-pruned with a Vermeer tree spade in 1991. In the year following, treated trees flowered profusely but did not fruit. Since then, cropping has controlled tree size. Ten years ex vitro `Granny Smith', `Oregon Spur II', and `Empire' trees can be managed without ladders. The goals of this study were: 1) to avoid “short life” problems and 2) develop a management scheme that would allow rapid entry of “bioengineered” cultivars into commercial orchards. Based on our research, selecting precocious cultivars or spur-type clones, in combination with transplanting 3 to 4 months ex vitro and root pruning show promise toward accomplishing these goals.

Application of shoot growth rules for understanding responses to pruning.

2022 ◽  
pp. 54-58
Author(s):  
T. M. DeJong
Keyword(s):  
Shoot Growth ◽  
Fruit Trees ◽  
Fruit Tree ◽  
Tree Size ◽  
Primary Reason ◽  
Close Proximity ◽  
Epicormic Shoot ◽  
One Year ◽  
Control Tree ◽  
Size Controlling

Abstract Knowledge of fruit tree shoot types is helpful to explain why pruning is often not successful in reducing tree size. In many horticultural circumstances, epicormic shoot growth can be considered as being almost exclusively stimulated by severe pruning of large branches (older than one year old) or strong water shoots in which sylleptic shoots have previously grown and "used up" the locations in close proximity to the pruning cut where proleptic buds would have been present in a less vigorous shoot. The strong growth response to heavy pruning is natural and is the primary reason why pruning cannot be relied upon exclusively to control tree size when trees are grown in highly fertile soils without size-controlling rootstocks. This chapter deals with understanding responses to pruning of fruit trees by application of shoot growth rules.

scholarly journals Effect of root pruning and irrigation regimes on pear tree: growth, yield and yield components

2014 ◽  
Vol 41 (No. 1) ◽  
pp. 34-43 ◽  
Author(s):  
Y. Wang ◽  
S. Travers ◽  
M.G. Bertelsen ◽  
K. Thorup-Kristensen ◽  
K.K. Petersen ◽  
...  
Keyword(s):  
Yield Components ◽  
Growth Yield ◽  
Fruit Yield ◽  
Root Pruning ◽  
Supplemental Irrigation ◽  
Promising Alternative ◽  
Yield And Yield Components ◽  
Pear Orchard ◽  
Negative Effect ◽  
Control Tree

The effect of root pruning (RP) as compared with non-root pruning (NP) and the potential of supplemental irrigation in alleviating the negative effect of root pruning on fruit growth, yield and yield components were investigated in a pear orchard from 2010 to 2011. Results showed that the total shoot length and the number of shoots per tree decreased by 72% and 43%, respectively, in the RP compared to the NP trees; however lateral root growth was stimulated by the RP treatment in the upper soil layers (30–40 cm). Full irrigation and deficit irrigation treatments stabilized the return bloom and improved fruit yield and size compared with the non-irrigated treatment without stimulating vegetative growth. Conclusively, the results indicate that root pruning is an effective practice controlling excessive shoot growth, and supplemental irrigation can improve fruit yield and quality in the root pruned trees. Therefore, a combination of root pruning and irrigation could be a promising alternative to control tree size and secure a stable fruit yield in pear orchards.  

scholarly journals Environment and tree size controlling stem sap flux in a perhumid tropical forest of Central Sulawesi, Indonesia

2011 ◽  
Vol 68 (5) ◽  
pp. 1027-1038 ◽  
Author(s):  
Viviana Horna ◽  
Bernhard Schuldt ◽  
Sarah Brix ◽  
Christoph Leuschner
Keyword(s):  
Tropical Forest ◽  
Tree Size ◽  
Sap Flux ◽  
Central Sulawesi ◽  
Size Controlling

scholarly journals Fruit Count, Fruit Weight, and Yield Relationships in `Delicious' Apple Trees on Nine Rootstock

HortScience ◽  
1993 ◽  
Vol 28 (8) ◽  
pp. 793-795 ◽  
Author(s):  
D.C. Elfving ◽  
I. Schechter
Keyword(s):  
Malus Domestica ◽  
Count Data ◽  
Fruit Weight ◽  
Principal Factor ◽  
Tree Size ◽  
Tree Age ◽  
Curvilinear Relationship ◽  
Sink Strength ◽  
Apple Trees ◽  
Size Controlling

Annual yields per tree for `Starkspur Supreme Delicious' apple (Malus domestica Borkh.) trees on nine size-controlling rootstock were related linearly to number of fruit per tree at harvest each year, independent of rootstock. Mean fruit weight was inversely and less closely related to number of fruit per tree when adjusted for tree size (fruit load). Annual yield-fruit count data for 9 years analyzed together showed that the number of fruit per tree was the principal factor determining yield, regardless of rootstock or tree age. A curvilinear relationship between yield and fruit count per tree during 9 years suggests that the sink strength of an apple crop is nearly, but not precisely, proportional to the number of fruit per tree.

Innovative protocol for “ex vitro rooting” on olive micropropagation

2011 ◽  
Vol 6 (3) ◽  
pp. 352-358 ◽  
Author(s):  
Annarita Leva
Keyword(s):  
Production Cost ◽  
Continuous Light ◽  
Ex Vitro Rooting ◽  
Propagation Time ◽  
Ex Vitro ◽  
Experimental Conditions ◽  
Continuous Growth ◽  
Olive Cultivars ◽  
Olive Trees ◽  
Commercial Micropropagation

AbstractThe commercial micropropagation of olive trees is currently limited by the production cost. An ex vitro method for olive microshoot rooting could reduce both the production cost per plant and the propagation time. In this study a successful ex vitro rooting protocol tested on seven olive cultivars is reported. The explants of cv. Maurino were collected from fifth, sixth, and seventh proliferative subcultures carried out on MSM medium, while for the other cultivars the explants were collected from only seventh proliferative subculture. Continuous light during the rooting phase was a prerequisite for the success of the ex vitro protocol. The best source of microshoots for a high rooting percentage was the seventh proliferative subculture. Cvs. Coratina, Maremmano, Maurino, Picholine, and S. Francesco showed high rooting percentages with a range of 62–76%; whereas for cvs. Correggiolo and Frantoio the experimental conditions need to be optimised. Up to 90% of the rooted microplants survived, and continuous growth of shoots was subsequently observed. The proposed protocol can be easily applied to several different olive cultivars to produce microplants by commercial laboratories. The approach makes olive micropropagation in the nursery industry both possible and profitable.

scholarly journals Pruning to control tree size, flowering and production of litchi

2013 ◽  
Vol 156 ◽  
pp. 93-98 ◽  
Author(s):  
Trevor Olesen ◽  
Christopher M. Menzel ◽  
Cameron A. McConchie ◽  
Neil Wiltshire
Keyword(s):  
Tree Size ◽  
Control Tree

Half-topping 'A4' macadamia trees has a markedly different effect on yield than full-topping

2016 ◽  
Vol 64 (8) ◽  
pp. 664 ◽  
Author(s):  
Trevor Olesen ◽  
David Robertson ◽  
Alister Janetzki ◽  
Tina Robertson
Keyword(s):  
Substantial Reduction ◽  
Size Control ◽  
Tree Size ◽  
First Year ◽  
Industry Practice ◽  
Second Year ◽  
Effect On Yield ◽  
Control Tree ◽  
Western Half ◽  
Yield Penalty

Mechanically hedging the tops of macadamia trees to control tree size is referred to as topping. Topping the entire upper canopy causes a substantial reduction in yield and is not a recommended industry practice. Here we compare topping just half the upper canopy with full-topping, and with control trees that were not pruned, to test whether half-topping is a more acceptable means of size control, with less of a yield penalty. We used macadamia cultivar ‘A4’ as the subject for the study. The trees were topped horizontally at anthesis. Full-topping reduced yields by 78% in the first year and 63% in the second year compared with the control trees. By the end of the second year the height of the fully-topped trees was approximately the same as that of the control trees. In contrast, topping just the western half of the upper canopy resulted in little yield penalty. Yields were reduced non-significantly by 14% in the first year, and negligibly in the second year, compared with the control trees; and by the end of the second year, the regrowth on the topped halves of the trees was only two-thirds the height of that on the full-topped trees. The results are encouraging because topping is simple and cheap, and would be an attractive tree size control option for growers at the yield penalty described here for the half-topped treatment.

scholarly journals Effect of Tree Size, Root Pruning, and Production Method on Root Growth and Lateral Stability of Quercus virginiana

2010 ◽  
Vol 36 (6) ◽  
pp. 281-291
Author(s):  
Edward Gilman ◽  
Forrest Masters
Keyword(s):  
Root Growth ◽  
Bending Moment ◽  
Production Method ◽  
Outer Edge ◽  
Tree Size ◽  
Root Pruning ◽  
Bending Stress ◽  
Cross Sectional ◽  
Tree Stability ◽  
Trunk Diameter

This research aimed to evaluate impact of slicing the outer edge of container root balls, initial tree size at planting, and root ball composition on post-planting tree stability in a simulated wind storm. One-hundred twenty Cathedral Oak® live oak were planted in March 2005. Thirty field-grown trees were transplanted, and 60 trees of similar size were planted from 170 L containers. Root ball sides on 30 containers were sliced prior to planting. Thirty smaller trees from 57 L containers were planted without slicing. Trees were pulled with an electric winch, and blown with a hurricane simulator in 2007. Slicing the root ball had no impact on root growth, bending moment, or bending stress. More bending stress was required to pull field-grown trees than trees planted from containers of either size. Growing trees in containers for three years prior to landscape planting changed root morphology compared to field-grown trees, which corresponded to reduced stability. Trees planted from small containers were as stable as those from larger containers. Root cross-sectional area windward correlated the most with bending stress required to tilt trees with a winch and cable. Bending moment scaled to the 3.4 power of trunk diameter.

Transformation of `Bosc' Pear (Pyrus communis L.) with the rolC Gene from Agrobacterium rhizogenes and Characterization of Transgenic Plants

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 461c-461
Author(s):  
Ralph Scorza ◽  
Richard L. Bell ◽  
Chinnathambi Srinivasan ◽  
Kevin Webb
Keyword(s):  
Plant Growth ◽  
Genetic Transformation ◽  
Genetic Improvement ◽  
Size Control ◽  
The United States ◽  
Tree Size ◽  
Native Promoter ◽  
Pyrus Communis L ◽  
Size Controlling

Pear production in the United States relies on a few major cultivars, including `Bosc'. While there is a need for new cultivars, genetic improvement of the existing major cultivars through genetic transformation could have a major impact on the industry. We have developed a system for regeneration and transformation of pear. While the major objective of the transformation project is to improve resistance to fire blight (Erwinia amylovora) in major pear cultivars, tree size control is also one of the objectives in the genetic improvement of pear that may be approached through transformation. Traditionally, manipulation of tree size and vigor in established cultivars has been achieved through the use of size-controlling rootstocks. There are no completely satisfactory size-controlling rootstocks for pear. Genetic transformation provides an approach to developing new size-controlling rootstocks and also to directly affect the growth of the transgenic scion cultivar using genes that affect plant growth such as the rolC gene isolated from the bacterium A. rhizogenes, the causal agent of “hairy root” disease. This gene has been shown to alter growth and development in a number of plant species. To investigate the potential utility of the rolC gene in altering the growth of pear trees, `Bosc' pear was transformed with A. tumefaciens EHA101 carrying a pGA482-based plasmid containing the NPTII and GUS genes, and the rolC gene under the control of its native promoter. Four clones were isolated that were kanamycin-resistant and GUS-positive. PCR assays and DNA blots indicated the presence of the rolC gene in these clones. Each transgenic clone has been multiplied in vitro and planted in the greenhouse where transgene expression and plant growth are being evaluated.

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