High Quality, High Tunnel Winter Strawberries

Jeff Martin, M.S. CandidateCrops Group

• Objective:Evaluate the quality of winter strawberry production when grown in high tunnels

Background• Strawberry plants under high tunnels were not

only better established, but also produced higher yields and quality than open field plants (Kadir et al., 2006).

• Early yields increased inside high tunnels when compared with those from open fields. Strawberry total marketable yields maximized inside high tunnels in comparison with open fields (Salam-Donoso et al., 2010).

Background

• Producing strawberries in the fall and following spring using high tunnels resulted in higher yields than those grown in the open field (Fernandez and Ballington, 2003).

• Tomatoes grown in high tunnels contained significantly higher levels of lycopene, sugars and red color (Wszelaki and Rogers, 2009).

Methods

• Six varieties compared • 4 replicated plots/variety inside and outside

high tunnels• 28 plants/plot with double-staggered row with

plants 12 in. apart on black plastic• Plants were fertilized once a week with fish

emulsion (1lb N/acre)• M-Pede, Aza-Direct and PyGanic were used for

insect control as needed

Pollination

Season 3- Plant Establishment• Fall planting (September 23, 2011)• All plugs

– June-Bearers• Chandler• Radiance• Strawberry Festival

– Day Neutrals • Albion• San Andreas• Seascape

Overwintering

Open Field: Ag-30 row cover

High Tunnel: Ag-19 row cover

Overwintering

High Tunnel (late December) Open Field (late February)

December Harvest

Yield characteristics measured:

• Marketable yield• Unmarketable yield

• Insect damage• Poor pollination• Cold damage

Season 3- Yields to Date

VarietyMarketable

Yield/Plot (lbs)Unmarketable Yield/Plot (lbs)

High TunnelsAlbion 1.2 1.2Seascape 0.5 0.7Chandler 0.2 0.9Radiance 2.8 2.0San Andreas 0.9 1.6Strawberry Festival 2.1 2.4

Bumblebee hives were placed in each tunnel November 10.Harvest began December 2; 6 harvests included until January 12.

Reasons for Unmarketability

VarietyInsect Damage (% by weight)

Poor Pollination

(% by weight)

Cold Damage (% by weight)

High TunnelsAlbion 49 23 30Seascape 51 21 26Chandler 67 27 5Radiance 77 14 7San Andreas 67 17 13Strawberry Festival 88 7 2

Lygus Bug Damage

2011 Fall- Fruit Quality

• Color• Firmness• Sugar content• Acidity• Shelf life

Colorimeter

• Used to objectively describe all the colors visible to the human eye.

• L= 0 yields black and L=100 yields white (lightness)

• a= negative values indicate green, positive values indicate magenta

• b= negative values indicate blue, positive values indicate yellow

Color Test

Variety L avg a avg b avg

High TunnelsAlbion 30.16 34.34 15.20Radiance 32.17 34.45 14.23Strawberry Festival 34.00 33.31 15.79P-value 0.1055 0.6942 0.5910

Force Dial™

• Measures firmness of fruit

• Wagner FDK 32• 1000 grams force x 10

grams force

Force Test

Variety Firmness (grams)

High TunnelsAlbion 299Radiance 256Strawberry Festival 300P-value 0.3869

Refractometer

• Reichert AR200 Digital Refractometer

• 1 degree Brix = 1 gram of sucrose in 100 grams of solution

• Represents the strength of the solution as percentage by weight

Soluble Solids

Variety Brix Value

High TunnelsAlbion 9.9 aRadiance 9.1 bStrawberry Festival 9.6 abP-value 0.0310

Season 3- Improvements• Winter high tunnel production• Excellent flavor, firmness and sugar content• Large berry size

Fire Ants

Parasitoids

Start of 2012 Harvest

Biodegradable Mulches for Specialty Crops Produced Under Protective Covers

Debra Inglis and Carol Miles (Project Directors)1;Andrew Corbin, Ana Espinola-Arredondo, Annabel Kirschner, Karen Leonas, Tom Marsh and Tom Walters1;

Doug Hayes, Bobby Jones, Jaehoon Lee, Larry Wadsworth and Annette Wszelaki2; Jennifer Moore-Kucera3; Russ Wallace4; Marion Brodhagen5 ; and Eric Belasco6;

1 25

SCRI Grant Award

No. 2009-51181-05897

43 6

Questions?