Site Selection for Strawberries in Mississippi

Eric T. Stafne Associate Extension Professor

Fruit Crop Specialist Mississippi State University

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

Frost • What is the frost-free date?

• How often can it be expected to occur during

growing season?

• Protection of plants

http://strawberries.ces.ncsu.edu/2013/03/what-growers-are-finding-out-this-morning-32213/?src=rss

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

Precipitation

• What is the average annual rainfall?

• When does it normally fall?

• Is drought a common occurrence?

• Is flooding a common occurrence?

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 planting area

• Look for “relative” elevation on site and plant near highest point

Low Elevations • More prone to frost

• Less air movement

• Poorer water and air

drainage

• More prone to disease http://ucanr.edu/sites/PAWMBA/Production_Projects/Strawberry/Overview_and_Management_802/

Slope/Aspect • The percent inclination or declination that varies from

horizontal

• Slight to moderate slope is desirable

• Important for cold air and water drainage

• Steep slopes (>15%) not recommended due to difficulty in equipment use and erosion potential

• Aspect is relation to sun, E and S are preferred to N and W

Prior Land Use • Compacted soils

• Prior crops grown on site

– Nematodes – Root rot fungi

• Pesticides used before

http://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/soils/health/biology/?cid=nrcs142p2_053866

Previous Crops • Do not plant in areas previously planted with

alfalfa, raspberries, potatoes, peppers, eggplant, etc. if <4 years ago

• Fumigation may be necessary

• Long-term rotation is best option if feasible

Soil Type • Soil content • Soil pH • Soil moisture • Soil erosion and surface water mgt

http://www.ipm.iastate.edu/ipm/icm/2000/7-24-2000/erosion.html

Soil Content • Strawberries grow in wide range of soil types

• Sandy loam and sandy clay loam preferred

• High clay content or very rocky make bed building

difficult

• Sandy soils require careful irrigation and nutrient management

Soil Characteristics • Ideal soil is well-drained

with adequate water-holding capacity

• Poor soil is poorly drained (internally or externally), and pH is not correct for the crop

http://www.omafra.gov.on.ca/english/crops/facts/frosprot_straw.htm

Soil Types

http://www.extension.umn.edu/yardandgarden/YGLNews/YGLN-May0105.html

Soil pH • Favorable root environment • Availability of essential nutrients • Soil pH is key factor • Ideal pH is between 6.0-6.2 • Do a soil test • Low pH one frequent problem • Correct soil deficiencies before planting

Soil pH

http://www.lsuagcenter.com/en/lawn_garden/home_gardening/Understanding+and+Improving+Soil+Fertility.htm

Soil Salinity and Alkalinity • Strawberries have low tolerance for salts

• Highly alkaline soils can cause chlorosis, yield loss

and plant die-back

http://www.fruit.cornell.edu/berrytool/strawberry/leavesandstems/strroundup.htm

Microclimate • Sunlight

• Adequate air-flow (but low wind speed)

• Water and air drainage

Light Requirements • Full sun is ideal

• Morning sun is preferable to afternoon sun

Air Movement • The more air drainage, the better

• Air movement provides disease and frost protection

Windbreaks • Wooded area

• Windbreaks on N or NW side of field

• Why?

– Cold protection

http://www.centerforagroforestry.org/practices/wb.php

Water Drainage • Surface drainage is most important; avoid standing

water • Internal drainage is related to soil characteristics • Raised beds compensate for poorly drained soils

http://ucanr.edu/sites/PAWMBA/Production_Projects/Strawberry/Strawberry_Management,_Summary/

Surface Drainage • Permits water to move quickly and completely

• Standing water >1 day will injure plants

Internal Drainage • Avoid poorly drained sites

• Poor drainage can lead to “yellowing” and result in

reduced yields

• Use drainage tiles if necessary

Soil Erosion and Surface Water • Raised beds help with drainage, but not always

enough

• Have enough slope to move water away from field without erosion

• > 2 % slope may lead to excess soil erosion

• Annual ryegrass can reduce erosion

Soil Moisture

• Supplemental Irrigation necessary

http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=3467

Irrigation Water Quality • Test first to determine quality

• Necessary for irrigation and frost protection

• Must have quality and quantity

• Food safety concerns

Strawberry Site Preparation

• Kill existing vegetation

• Apply soil amendments

• Construct beds

• Provide for drainage

Row Orientation • North to South best

– More uniform plant stands – More uniform ripening

• If field is flat, soil drainage most important

Weed Control in Strawberry • Kill perennial weeds

before planting

• Excess fertilization favors weeds

• Keep planted beds free of weeds

Wildlife • Protection from deer critical to success • Other potential pests • Rabbits • Moles • Voles • Coyotes

Crop Rotation • Rotate as often as possible

• Not always practical

• Avoid rotations with crops treated with:

– Herbicides – Plant growth regulators (PGRs)

• Could be carryover

Cover Crops • If rotation not possible, consider summer cover

crops – Reduce soil erosion – Improved soil structure – Improved soil stability and permeability – Decreased crusting – Increased water infiltration

• Incorporate into soil before fall planting

Important Site Components • Windbreaks • Row Orientation • Crop Rotation • Cover Crops • Wildlife • Soil Type • Surface Drainage • Soil Tilth • Internal Drainage • Soil pH • Salinity and Alkalinity • Previous Crops • Irrigation Water Quality • Microclimate

BREAK

Cultivar Selection for Mississippi Strawberry

Production

Eric T. Stafne Associate Extension Professor

Fruit Crop Specialist Mississippi State University

• Consistent yields • High yields • Good flavor • Pest resistance • Increased shelf life (firmness without sacrificing

flavor and texture) • Aromas

Priorities in Cultivar Selection

Strawberry Cultivar Selection • Select locally adapted cultivars • Cultivars differ in sweetness, preservation quality,

pest resistance and fruiting period. • Plant multiple cultivars to prevent crop loss to

disease and frost events • Find a reliable and experienced nursery • Place your order early

Plant Quality

• Healthy looking

• No disease, insects, nematodes, virus

• True-to-type

• Do not let roots dry out

Plant Types

• Plugs – Most expensive, easier to plant, less

perishable, establish quicker, recommended

• Freshly dug – Highly perishable, hand transplanted

• “Cutoff”

Disease Resistance

• Reduces number of sprays

• Choose cultivars with resistance if possible/practical

• Not all diseases exist in all locations

Anthracnose

Botrytis

Botrytis cinerea

• Young blossoms susceptible to Botrytis

• Fruit infections - soft, light brown, enlarge rapidly

Annual vs. Perennial Production

• Growing systems – Annual production on black plastic: plant

in fall, harvest in spring

– Matted row: rejuvenate beds by allowing daughter plants to grow

Perennial Production System

Beds

Annual Production System

Plastic Covered Beds

Plant Spacing • Spacing depends on cultivar and equipment

• Strawberries are planted in 30-inch-wide raised

beds

• Space beds 4 to 5 feet apart

• Space plants 12 to 15 inches in two staggered rows 12 inches apart

Pollination

• Most cultivars are self-fertile • Pollen from other cultivars may

improve fruit set and quality • Insect pollination (primarily bees) is

required

Strawberry Cultivar Selection Bearing types

• June-bearing - Produce a single spring crop

• Everbearing - produce 2 main crops, require long days (12+ hrs of light)

• Day-neutral – insensitive to daylength, but don’t tolerate heat well

June Bearers

• Best for Mississippi • Produce one large crop per year • Have largest berries • Season is 2-3 weeks long • Best yield and quality

Day-Neutral

• Flower and fruit set adequate when temps between 35 and 80 °F.

• In milder growing regions can produce fruit continually throughout year

• Small berry size • Not suitable for Mississippi growing

conditions

Everbearing

• Produce two crops per year • Spring and Fall • Few runners • Smaller crops, especially fall • Fruit quality less

Proven Southern Cultivars

• Chandler

• Sweet Charlie

• Camarosa

Chandler

• Industry standard • High yields • Good flavor, size, color • Cold hardy

Sweet Charlie

• Early market • Has good quality early, but falls off • Sweet fruit • May be more susceptible to crown rot

Camarosa

• Widely grown around the world • May not yield as much as Chandler • Fruit is large and firm • Plant is vigorous • Susceptible to anthracnose • Harvest at darker color for best quality

FL Production vs. Price 1997-2007

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Florida Strawberry Total Value 1997-2007

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Other Strawberry Cultivars to Consider – Earliglow

– Ventana – Strawberry Festival – Ovation – Oso Grande – Gaviota – Radiance – More…

Intellectual Property • Plant patents -- 20 years from application

– Grower cannot propagate more material from these plants without contract with patent holder

– Royalties paid – May be tempting, but also illegal

• Trademarks – Indefinite