General
Characteristics of Small Fruit (Temperate zone)
Reading: Chapters 1 & 2 in Small Fruit Crop Management
Dicotyledonous angiosperms
flowering plants with netted-veined leaves
Fruit types:
true berries (blueberries, grapes, kiwi, gooseberries, currants)
aggregate (brambles)
accessory (strawberry)
Perennial plants:
Usually woody, sometimes herbaceous
Growth Habits:
Herbaceous plants
strawberries
Thickets or hedges
Brambles (raspberry and blackberry)
Shrubs or bushes
Blueberries (highbush, lowbush and rabbiteye)
Gooseberries & currants
Vines
climbing- grapes, kiwi
creeping- cranberries
Genetically Heterozygous (dissimilar alleles at many loci)
Do not propagate true from seed
Vegetatively reproduced (as well as seed reproduction in nature)
General
Development Cycle of Small Fruit Crops
Fruit buds develop on previous season's growth -
-all small fruits except day-neutral strawberry and fall-bearing raspberries
Cultivated
Small Fruit Genera
Fragaria (strawberries)
Rubus (raspberries and blackberries = brambles)
Ribes (currants and gooseberries)
Vaccinium (blueberries, cranberries)
Vitis (grapes)
Actinidia (kiwifruit)
History
of Small Fruit Production
Gathered from wild - prehistoric times to present
favored over other foods because of flavor, accessibility, sense of well-being derived from eating fresh fruit, food and medicinal uses common
Cultivation - only in last 2 to 4 centuries (except grapes where evidence of grape culture dates back 5,000 to 6,000 years)
Blueberries are the most recent to be cultivated. Early work by Frederick V. Coville, USDA, Maryland started in 1908 with collections from the wild.
Advantages of Small Fruit Production
1. Commercial Production:
a) Economics: high cash returns per acre compared to other crops.
b) Diversification in agriculture
c) Additional income at times of the year different than other crops
d) Particularly suited to small acreage and reduced input - weekend farmers
e) Work for the entire family - a way for all to contribute
f) Quick returns on investment - low investment in land and equipment
g) Ideal for Pick-Your-Own -
h) Good, healthy food - good to excellent source of vitamins, minerals, fiber;
i) Widely adapted to many different climates
j) Lower pesticide requirements than some other crops. May have low pesticide residues
2. Home Production: - easy and popular for home gardens
a) small space required - 100' of strawberry row = 50-100 quarts of berries
- 4 blueberry bushes 40-60 lb. of berries
b) Consistently productive
c) Less pest problems than some vegetables and tree fruit
d) Quality - fresh-picked is better than store-bought, so home production is preferred
e) Landscape Use - attractive plants, versatile use
f) Ideal for home processing - easy to prepare and freeze or can
Disadvantages of Small Fruit Production
1. Marketing!
2. Perishable nature of small fruits
3. Prone to weather related loss of production
4. Prone to diseases, insects, and weeds
5. Quality standards are very high
World
Production of Small Fruit
FAO (United Nations Food and Agriculture Organization)
Production records are kept for 4 major fruit crops:
Apples
Citrus
Bananas
Grapes (20% of total fruit production)
Production estimates are made for other fruit crops
Berries ~1% of total fruit production
strawberries, raspberries, currants
Good records are not possible because:
Small fruit are highly perishable ~ marketing quickly
Grown close to markets
Sold direct to consumer
Small
Fruit Production in Indiana
Crop Acres
US Rank Value
All berries 1,226
Strawberries 501 A 11th $1.5 mil
Blueberries 606 A 12th $3.5 mil
Raspberries 63 A 17th $0.2 mil
Blackberries D NA
Grapes 559
A 22th $2.5 mil
Source: 1997 Census of Agriculture
Tree Fruit Production in Indiana
Apples 3,209 A $10 mil
Peaches 565 A $2.5 mil
other (plums, pears, etc.) 100 A $0.5 mil
Factors that Influence Small Fruit Production
I) Climatic Factors:
1. Winter Cold: Sub-zero temperature are the most limiting of the climatic factors.
A) Selection of variety
B) Selection of site
C) Cultural Practices
2. Spring Frosts:
A) Site Selection:
B) Sprinkler irrigation for frost control: especially Strawberry
C) Floating row covers: especially Strawberry
3. Length of growing season: Frost-free days
4. Cumulative Growing Degree Days: (heat summation)
GDDs = daily max temp + daily min temp - 50˚F (base temp)
2
5. Rainfall (amount & distribution)
Irrigation
6. Summer Heat: Most Small Fruit do not tolerate temperatures > 90 - 100 °F for extended periods.
A) Sprinkler irrigation
B) Partial shade
Climate
3 levels of climate:
Macro - Large regional effects
Meso - (topoclimes) localized site effects
Micro - climate within and around the plant canopy
Region adaptation of small
fruits
There are 10 regions in US that differ in adaptation for small fruit crops.
(See Small Fruit Crop Management pg. 25)
How climate affects plants
Mid-winter low temperature damage
Intracellular freezing and ice formation causes cell wall/membrane rupture, cellular leakage, membrane disruption, and eventual cell death.
1. Fruit buds
2. Woody tissues
3. Crowns (strawberries)
4. Roots
Factors that affect degree of injury
1. Degree of low temperature
2. Duration of low temperature
3. Pre-freeze environmental conditions
4. Stage of plant growth or dormancy
Relative Cold Hardiness of Small Fruit Crops
Crop Critical Temp ˚F
Grapes
Vinifera (European) 0 to –5
Labrusca (American) -15 to –20
Hybrids -10 to –40
Strawberries -25 when mulched
Blueberries
Highbush -20 to -30
Lowbush -20 to -30
Rabbiteye 0 to -10
Brambles
Summer red raspberries -25 to -40
Fall red raspberries -20 to -30 (NA if mowed)
Black raspberries -15 to -20
Thorny blackberries -5 to -15
Thornless blackberries 0 to -5
Spring frost hazards
1. Flowers / flower buds
2. Developing shoots
Conditions that contribute to frost: Radiative cooling
1. Clear skies
2. Cool temperatures
3. Low relative humidity / dew point
4. Calm winds
Advective cooling (cold fronts, typically windy, may be below freezing)
Seldom leads to frost, but may cause freeze damage
Effects of slopes on freeze / frost probabilities
Warm air rises, cold air falls
Cold air settles in valleys and other low-lying areas
Slope Exposure (Aspect)
South face of hill in warmer than north face – less frost
Advanced maturity – increased frost damage
Effects of large bodies of water on frost probabilities
water acts as a heat sink
“Specific heat” of water is higher than other substances
Delayed frosts in fall
longer growing season, better hardening
Delayed warmth in spring
delayed growth in spring
avoid frost
Prevents cool temperatures
Effects of soil surface on minimum temperatures
Surface Temperature
Bare soil; firm, moist warmest
Shredded cover, moist 1/2˚F colder
Low cover crop; moist 1-3˚F colder
Bare soil, firm, dry 2˚F colder
Bare soil, loose 2˚F colder
High cover crop 2-4˚F colder
High cover, weedy rows 6-8˚F colder
Critical Temperatures for tissue damage
State of development Bud
Status
Wet Dry
Grapes
scale crack 22 15
First swell 24 18
Full swell 26 19
Bud break 26 21
Exposed shoot 27
Strawberries
Bud emergence 10
Tight bud 22-27
Bloom 30
Fruit set 28
Dormancy & Chilling
Requirement
Dormancy:
Absence of active growth is usually due to an increase in growth inhibiting hormones in response to decreasing daylengths and temperatures.
1. Eco-dormancy
regulated by environment
2. Ecto-dormancy
regulated by physiological factors outside affected structure
3. Endo-dormancy
regulated by physiological factors inside affected structure
a) rest
b) quiescence
Chilling is required to break (overcome) dormancy (rest)
Chilling requirement is meet by accumulating hours of cool temperatures (usually considered to be 34-45˚F or 0 to 7˚C)
Chilling Requirement
Crop Hours
of chilling (32-45˚F)
Grapes
vinifera 100-400
labrusca 1200-1500
Strawberry 200-300
Blueberry
Rabbiteye 200-500
Highbush 650-850
Blackberry
Thorny 200-600
Thornless 700-1100
Raspberry 800-1700
reds least, blacks most
Currant 800-1500
Gooseberry 800-1500
Kiwifruit (fuzzy) 500-600
Cranberry 2000
II) Soils:
Natural Resources Conservation Service (Soil Conservation Service) Soil Surveys provide detailed information about soil properties and suitability of soils for fruit crops.
Important characteristics:
Drainage class, Depth to water table, Water-holding capacity, Permeability, Rooting depth, Texture, pH, Trafficability, Rockiness, Slope, Erosion
Soil Drainage:
“The ability of a soil to drain excess water from the entire soil profile yet retain sufficient water for normal plant growth”
One of the most important
aspects of soils for fruit production.
Drainage classes:
Poorly drained
Somewhat poorly drained
Moderately well drained
Well drained
Drainage of agricultural land:
1. Surface drainage:
Surface reshaped to eliminate ponding and establish slopes sufficient for gravitational flow overland and through channels to outlets
2. Subsurface drainage:
Ditches and buried drains are installed within the soil profile to convey excess groundwater to an outlet.
Subsurface drainage lowers the water table and increases the potential rooting depth.
Soil permeability:
Speed and ease of water movement through the soil profile
Addition of organic matter increases permeability, ease of rooting, etc.
Soil Composition:
Mineral and organic matter
Water
Air
Living organisms
Typical silt loam topsoil consists of:
50% pore space (1/2 water, 1/2 air)
45% mineral matter
5% organic matter
Soil Type:
Mineral soils: <20% organic matter
Muck soils: 20-65% organic matter
Peat soils: >65% organic matter
Soil Texture:
Proportion of particles of various sizes.
Clay: <0.002 mm
Silt: 0.002 to 0.05 mm
Sand: 0.05 to 2 mm
Gravel: > 2 mm
Typical Loam textured soil contains:
35 to 45% sand, 35 to 45% silt, and 10 to 25% clay
Sand: good drainage
poor water holding capacity
high amount of air space
low in organic matter – low CEC
nutrient leaching problems
Clay: poor drainage
high moisture holding capacity
low amount of air space, poor aeration, waterlogging
increased disease problems
poor root penetration
harder to cultivate, poor workability
high CEC
Loam: mixture of sand, silt, clay
moderate drainage
moderate water holding capacity
moderate amount of air space
medium CEC
Soil Moisture:
Field capacity: water remaining 2-3 days after saturation
Permanent wilting point: percent of soil moisture at which a plant will not recover (15 bar)
Available water: percent between field capacity and PWP
Soil Chemistry:
Nutrient supplying power of soil = soil capacity
Cation Exchange Capacity:
Total number of exchangeable cations a soil can hold
Cations held on colloids (Ca++, K+, etc.) can be exchanged for H+
CEC depends on amounts and kinds of clay and organic matter.
Soil Organic Matter:
Plant and animal residues in various stages of decay.
OM improves physical and chemical condition of soil.
OM serves as a source of energy for microorganisms and source of supply of plant nutrients.
Microorganisms (esp. bacteria) produce complex carbohydrates that cement soil particles together in aggregates: improves soil structure
Soil Acidity and Liming:
Soil acidity expressed in pH.
Soil pH and Buffer pH:
Soil pH tells the acidity of the root environment
Buffer pH tells how much limestone is required to change the pH to neutral.
Liming requirement is based on pH and buffering capacity.
Buffering capacity increases with increased clay and OM.
Benefits of liming:
Reduces acidity and provides more favorable environment for growth of soil microorganisms.
Increases availability of phosphorous, especially in soils high in Al and Fe.
Decreases K+ loses by leaching and increases K+ availability.
Supplies Ca++ and Mg++
Improves structure of acid clay soils by causing clay particles to aggregate.
Increasing soil pH results in precipitation of toxic Al, Mn, etc.
Increases effectiveness of certain herbicides.
Ideal Soil for Small Fruit
Production
Deep (30"+)
Well drained, not waterlogged, low water table - tile drained
Medium to light sandy loam
High organic matter content
Naturally fertile
Free of troublesome weeds, diseases and insect pests
III) Site:
Importance to production:
Full sun exposure
Good air drainage
elevated above surrounding land to avoid frosts, dew
Source of water (irrigation)
Importance to marketing:
Pick Your Own (PYO)
Close to large population
Good signage, easy to find, easy access
Parking, shade, etc.
Wholesale (shipping, processing)
Close to major production area
Close to outlet (processor)