strategies for site selection of orchards & vineyards...strategies for site selection of...
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Strategies for Site Selection of Orchards & Vineyards
Eric T. Stafne Associate Extension Professor Fruit Crops Specialist Mississippi State University Poplarville, MS
“You can have the most beautiful plant in the world, but if it won’t survive outside, it’s worthless”.
Hardiness Zone Map
Climate Scales
Macroclimate – large geographic region
Mesoclimate – local climate
Microclimate – specific environment around the plants Related to plant growth and development post-
site selection decision
Macro Site Selection Considerations
Length of growing season
Coolness of the dormant season (chilling)
Frost
Frequency of extreme low temperatures
Summer high temperatures
Precipitation
Length of Growing Season
Some fruit crops may not ripen if growing season is too short Some grapes (especially red
varieties) need longer season to fully ripen
Some pecan varieties will not ripen until November or later thus being potentially exposed to shuck freeze damage
http://northernpecans.blogspot.com/2011/11/why-wont-some-pecan-shucks-split-open.html
Chilling Requirement A chill hour can vary depending on the model used, but the
most common model defines it as the number of hours below 45 °F
This is a requirement for the plant to satisfy its dormancy and thus to grow and fruit normally the following year
In regions where cold temperatures are more common, plants can remain in a quiescent (waiting for a warm up) phase even after their chill hour requirement has been met
However, in warmer climates this may not be the case, so early flowering is a problem in low-chill varieties
Frost
Can be damaging early in the growing season (bloom) and late in the season (pre-hardening off)
Choose sites with low likelihood of these events
Photo by B. Carroll, Oklahoma State University
Frequency of Extreme Low Temps
Some fruit crops are not very winter hardy
Very important for growing species/varieties on the fringes of their adaptation
Often other varieties or species are available to overcome this issue
Citrus Cold Tolerance (°F)
Kumquat 16-17 Satsuma 18 Calamondin 21-23 Orange, grapefruit 23-24 Lemon 26-27 Lime 28
Fruit potentially damaged below 32 °F.
Summer High Temperatures
Extreme high day and night temperatures in summer can limit some species
Fruit quality may suffer as respiration exceeds photosynthesis
Flowering inhibited when temps over ~80-85°F Primocane-fruiting blackberries Red raspberries (esp. fall-fruiters) Strawberries
Primocane-Fruiting Bramble Varieties
Not recommended for commercial production, rather for home garden use and limited commercial trial
Poor performance for primocane crop in high heat Heat in late July to early Sept. greatly reduces fruit set,
quality, and yield Appears that temps of ~85 oF for several consecutive
days cause these problems, and even later-season cool temperatures do not bring the fruiting potential back strongly
Precipitation What is the average annual rainfall?
When does it normally fall?
Is drought a common occurrence?
Is flooding a common occurrence?
Many fruit species do not tolerate standing water for extended periods of time (for example: stone fruits and blueberries)
Some fruit species can tolerate drought conditions, but not for long periods of time (for example: pears, pecans, blackberries)
Meso Site Selection Considerations
Elevation Topography Slope Aspect Prior land use Soils Pests and other threats
Elevation
Can have a big influence on minimum and maximum temperatures in orchard/planting area
One of the most important considerations before planting
In much of Mississippi look for “relative” elevation on site and plant near highest point
Important for frost mitigation
Low Elevations
• More prone to frost
• Less air movement
• Poorer water and air drainage
• More prone to disease
Photo Mississippi State University Extension Service
Topography
Includes the “absolute” elevation of a site
How many feet above sea level?
Slope
The percent inclination or declination that varies from horizontal
Slight to moderate slope is desirable
Important for cold air drainage
Also for water drainage
Steep slopes (>15%) not recommended due to difficulty in equipment use and erosion potential
Water Drainage
Surface drainage is most important; avoid standing water
Internal drainage is related to soil characteristics Stone fruit and blueberries are intolerant of wet
soil
Best planting location often is on top of a hill or on a slope
Raised beds compensate for poorly drained soils
Good Drainage Situation
Photo Mississippi State University Extension Service
Poor Drainage
Photo Mississippi State University Extension Service
Air Movement
The more air drainage, the better
Air movement provides disease and frost protection
Avoid hedgerows on the lower side of the orchard
Aspect In reference to the slope – what is the
prevailing compass direction that the slope faces?
Aspect affects sunlight angle interception
Not as important as some other considerations
If possible, eastern exposure (or NE, SE) is better than western exposure
Aspect Attributes
East = early morning sun that dries off foliage, starts photosynthesis earlier, cooler, later budbreak in spring
West = hottest, late day sun exposure
South = also hot during summer, may promote earlier budbreak in spring, longer growing season
North = cooler during summer, later budbreak in spring, colder in winter, shorter growing season
Light Requirements
• Full sun is ideal
• Morning sun is preferable to afternoon sun
Prior Land Use
Compacted soils
Prior crops grown on site Nematodes
Root rot fungi
Pesticides used before
Soils For Fruit & Nut Trees
Depth Effective rooting depth May be limited by rock, water Minimum of 3 feet in most cases Slightly acidic soil best
Drainage Internal: berm, perk test External: slope to open area
http://www.nrcs.usda.gov/wps/portal/nrcs/detail/ak/soils/surveys/?cid=nrcs142p2_035915
Soil Types
http://www.extension.umn.edu/yardandgarden/YGLNews/YGLN-May0105.html
Soil Characteristics
• Ideal soil is well-drained with adequate water-holding capacity
• Sandy loams are best
• Poor soil is poorly drained (internally or externally), and pH is not correct for the crop
Photo Mississippi State University Extension Service
Soil pH
http://www.lsuagcenter.com/en/lawn_garden/home_gardening/Understanding+and+Improving+Soil+Fertility.htm
Pests and Other Threats
Disease Insects Weeds Animals Birds Allelopathic plants Neighbors
Variety Selection
• Adaptability to your area - very important
• Disease resistance
• Self-pollination versus cross-pollination
• Desired harvest date
• Taste, sweetness, size, texture, etc.
The Variety Equation
What does it take to select and maintain an appropriate variety?
AV = [(G x E) +((SS x M) + LE))]xL
where:
AV = Appropriate Variety
G = Genetics
The variety must have the necessary genetic elements to succeed
E = Environment The environment will interact with the genetic
components of the variety to impact the outcome, i.e. yields, quality, and survival
SS = Site Selection Fruiting plants placed on the wrong site, including
considerations like water availability and quality, soil quality, nutrient availability, air and water drainage, accessibility, etc. will dictate final outcomes
M = Management
Good management can help offset some factors such as less than optimal site selection and improve plant health and fruit quality
LE = Learning and Education Education should be a never ending task for a
fruit grower, but a good knowledge of the basics should be garnered before putting a plant in the ground
L = Luck All of the best laid plans can be disrupted with
bad luck — drought, freezes, broken pumps, plugged emitters, birds, plague of locusts, etc., because once your luck turns to zero, so does your AV
Some Examples Concord grape – doesn’t tolerate heat well, susceptible to
PD
Flame Seedless grape – susceptible to PD
Highbush blueberries – not heat tolerant, high chilling requirement
Sweet Cherries – do not tolerate heat, high chilling requirement
Citrus – cannot tolerate much cold
News You Can Use
Mississippi Fruit and Nut Blog
http://msfruitextension.wordpress.com/
My email: [email protected] (best option)
My phone number: 601-403-8939
Twitter: @EStafne