VCHERRY The Virtual Cherry Tree Program for: - PowerPoint PPT Presentation

Title: VCHERRY The Virtual Cherry Tree Program for:


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VCHERRY The Virtual Cherry Tree Program
for - Developing and Testing Pruning and
Training Decisions - Evaluating Their Impact on
Sweet Cherry Yield and Fruit Quality Gregory
Lang, Michigan State University and Robert J.
Lang, Origami Art Engineering
MSU Tree Fruit Research
Visit our website www.hrt.msu.edu/faculty/langg.h
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Rationale New precocious, dwarfing rootstocks
such as the Gisela series can alter sweet cherry
growth and cropping patterns significantly.
Orchard management strategies to balance
sufficient leaf area with a modest crop load is
challenging, yet critical for optimized yields of
large and high quality fruit to achieve premium
market returns.

• The Selectable Orchard Parameters Window
• Environmental Inputs for Orchard Location
  Genetic Inputs for Orchard Production
• Soil type ? fertile (deep, loamy) -
  Cultivar ? Bing or Ulster
• ? poor (shallow, sandy) ? Rainier
• ? Lapins
• Regional climate ? Great Lakes ? Regina
• ? Pacific Northwest ? Sweetheart
• ? California
• - Rootstock ? vigorous (e.g., Mazzard
  or Mahaleb)
• These choices affect growing season duration,
  ? semi-vigorous (e.g., Gisela 6 or 12)
• daily light integral, annual growth vigor, etc.
  ? dwarfing (e.g., Gisela 5)
• These choices affect fruit size
  potential, fruit color, ripening time,
  branch angle, tree vigor, etc.

• Objective
• To integrate emerging and fundamental genetic and
  physiological knowledge of sweet cherry tree
  growth, canopy architecture, cropping,
  rootstocks, and varieties into an interactive
  computer model for growers to
• - simulate multi-season tree develop-ment to
  facilitate testing and teaching of orchard
  pruning and management strategies with new
  rootstocks
• predict the short- and long-term effects of
  management decisions on future yields and fruit
  quality

• Visualization of Tree Growth Window
• The virtual tree grows on a week-by-week basis
• Leaves expand, flowers open and become growing
  fruit, shoots elongate, fruit ripen, leaves turn
  yellow and fall, buds go dormant
• - The orange cone (above) is the marker to
  identify individual buds or spurs for orchard
  management actions

Year 1 Growth (Nursery)
Year 2 Growth (Orchard)
Sweet Cherry Growth and Flowering Habit -
Fruiting is primarily on 2-year- and older
spurs - The fruit at the base of the previous
years new shoots is generally of the highest
quality due to high (localized) leaf
area-to-fruit (LAF) ratios - Pruning decisions
have both long- and short-term consequences for
development of canopy leaf populations, LAF
ratios, and therefore sustainable production of
high quality fruit
Typical Tree Training Techniques include Bud
manipulation removal, activation (real and
virtual examples above) Branch bending, shoot
pruning (heading or thinning cuts), sucker
removal Tipping of new shoots, fruit spur
thinning, flower cluster thinning
A 4th Leaf Virtual Cherry Tree Trained as a
Whorled Axe
A 4th Leaf Sweet Cherry Tree Trained as a Whorled
Axe
The Virtual Cherry Computer Program The Virtual
Cherry Tree grows bud-by-bud, leaf-by-leaf,
shoot-by-shoot, with upper shoots inhibiting the
outgrowth of lower buds (apical dominance).
There are a variety of pruning and training
commands available to alter the natural growth
and cropping patterns. There are 9 different
computer screen windows in VCHERRY v
Visualization of Tree Growth (the main
tree-growing window) v Selectable Orchard
Parameters (to customize the virtual orchard to
represent the site, rootstock, and variety to be
simulated) v Quantitative Tree Growth Information
(to track the development of, and management
effects on, leaf area and crop load) v
Interactive View Controls (to virtually walk
360º around the tree) v Visual Resolution
Settings (to speed up simulated growth
sessions) v Interactive Marker to Select
Meristems (to pick specific buds for pruning or
thinning or activation) v Quantitative Data Plots
(to graph out changing leaf area and crop loads
over the current season or over several years) v
Growth Session Command Log/Script (to record
every step of each orchard management session for
later use or editing) v Keyboard Command List (an
on-screen reference guide for which keyboard
strokes are used for each training command)
Analysis of Tree Training Effects on Cropping
Simulation sessions can be initiated, before
the real orchard is even planted, to envision
years of training and crop load management
decisions to compare training systems, predicted
yields, labor inputs for pruning, and fruit
quality. Or, simulation sessions can be
conducted prior to each spring to test potential
pruning strategies for optimizing canopy
development, crop load balancing, fruiting wood
renewal, etc.
Visual and Quantitative Outputs The VCHERRY
trees and outputs (figures to the left) compare
the predicted tree architectures, crop loads, and
LAF ratios for 4-year-old Bing / Gisela5
trees trained to 3 different systems. VCHERRY
can remove and replace leaves at any time to
reveal where the crop is being borne in the
canopy. The VCHERRY analysis reveals similar crop
loads and LAF ratios for the Whorled Axe and
Solaxe trees, but a higher proportion of non-spur
(NSp) fruit borne on the Whorled Axe trees these
are more likely to be of the highest quality. The
Steep Leader tree has a smaller crop load and
thus a better LAF ratio, along with a
well-balanced proportion of non-spur and spur
(FSp) fruit, suggesting that while yield will be
lower, fruit quality will be higher throughout
the canopy.
Financial support from the International Fruit
Tree Association, Gisela Inc., California Cherry
Advisory Board, and Michigan Agricultural
Experiment Station is gratefully acknowledged.