1.Off-Season Hydroponic Strawberry Production Chieri Kubota and Mark Kroggel School of Plant Sciences University of Arizona

2. December, Japan 3. January, Mexico 4. Our goal To reintroduce AZ strawberry production in a more sustainable system Winter production (Harvesting from November to April) To develop comprehensive information resources 5. Key Technologies Ever-bearing cultivars (no need to induce flowers to start producing early) Aggregate hydroponics using raised troughs with selected substrate mix (high porosity) Daily monitoring/adjustment of EC, pH, and %drainage Night time VPD (RH) control (high RH for 3 hrs) Glazing with high UV transmission (ETFE) Daylength extension lighting (3 mmol m-2 s-1) for facultative long-day response 6. Hydroponic system at UA Substrate system in raised troughs 7. Styrofoam trough system (Ishiguro Nozai Co.) Substrate volume: 22 L per meter Substrate volume per plant: 2.4 L (>2 L is recommended) Composition: 50% Perlite + 25% Coco coir + 25% Peat (Air porosity: 15.6% @4.5 inch column) (Ishiguro-Nozai Co.) 8. www.bato.nl Hanging bucket system (Bato Plastics) Volume: 11 L per bucket (2.8 or 3.7 L per plant at 4 or 3 plants per bucket) 9. Night time VPD control for tipburn Inducing high xylem pressure at night (inducing guttation) Under-trough misting (intermittent) to achieve 95% RH inside the canopy for 3 hours 10. Glazing with high UV transmission ETFE (ethylene tetrafluoroethylene) High UV and PAR transmission Converting direct light to diffuse light Long life 11. Extending the day length or interrupting the night (Needed for cultivars that are extremely sensitive to day length to enter dormancy) Target light intensity: 2-3 mmol m-2 s-1 Commercial greenhouse with NI lighting UA Greenhouse 12. January 21 13. Cultivation practices (2013-2014) Cultivars: Albion and Portola Transplants: Rooted runner plants Planting density: 8 or 12 plants/m2 Transplanting: August 10th, 2013 First harvest: September 22nd, 2013 Nutrient solution: Yamazaki Strawberry Formula (EC = 1.0) Temperature setting: 25C/10C (day/night) Cultivation practices Leaf pruning Crown pruning (when needed) Drip irrigation (33 mL/plant per event; 20-30% drainage) Pollination: Electric pollinator 14. Off-Season Hydroponic Strawberry Production Benchmarks Yield per crop: 7 kg m-2 (vs. open field yield in CA = ~3 kg m-2) Fruit size: 20 g per fruit Brix% (total soluble solids): 7%** Titratable acidity: 0.8% (or 8 g/L)** **UC Davis recommendations 15. Treatments Fruit size (S.D.) All 24.41.2 g (max 52.1 g) LD = Low Density (8 plants/m2) Bucket HD = High Density (12 plants/m2) Bucket Styro = Low Density (8 plants/m2) Styrofoam trough Benchmark: 7 kg/m2 kg/m2 NS 16. Treatments Fruit size (S.D.) All 19.71.4 g (max 51.8 g) LD = Low Density (8 plants/m2) Bucket HD = High Density (12 plants/m2) Bucket Styro = Low Density (8 plants/m2) Styrofoam trough Benchmark: 7 kg/m2 kg/m2 NS 17. Fruit quality affected by cultivar and season ----- Levels of UC Davis recommendations (> 7 for Brix; < 0.8% for TA) Albion (TSS) Portola (TSS) Albion (TA) Portola (TA) 18. Greenhouse environments Shade removal Shade applied Daily Light Integral (integrated PAR) Air temperature (Max, Min, Mean) 19. Root-zone pH 2nd flush1st flush 3rd flush 20. Diurnal change of strawberry Pmax PAR = 1000 mmol/m2/s CO2 = 380 ppm 21. A bit about economics of production Item Tomato Strawberry Comments Production Time 12 months (year round) 9 months (6 months in production) 10,000 ft2 GH Benchmark Yield 50 kg/m2 or 10.2 lb/ft2 7 kg/m2 or 1.4 lb/ft2 Production Costs (variable costs only) $0.68/lb* or $6.89/ft2 $3.31/ft2** ~50% of tomato Total Costs (including depreciation***) N/A $3.94/ft2** Not including GHs Market price $2.00/lb $5.00/lb Gross profit $13.5/ft2 $3.7/ft2 Not including depreciation *After the costs reported by Pena (2005) http://aggie- horticulture.tamu.edu/greenhouse/hydroponics/economics.html **U of AZ estimate (Tucson) ***Troughs, irrigation system, plastics and cooler (greenhouse not included) 22. Production costs (/ft2) (10,000 feet greenhouse in Tucson, AZ) Items Costs ($/ft2) Comments Labor $1.54 (39%) 1,560 person-hours Utilities - Gas $0.32 (8%) Virtual Growers Utilities - Electricity $0.32 (8%) Utilities - Water $0.12 (3%) Municipal water Plants $0.13 (3%) Substrates $0.29 (7%) Pre-mixed Plastics $0.02 (0.5%) Fertilizers $0.40 (10%) Yamazaki strawberry formula Bees $0.10 (3%) IPM $0.07 (2%) Equipment Amortized $0.63 (16%) Irrigation, troughs, plastics, cooler facility Total costs $3.94 (100%) 23. Future Key Technologies needed for Strawberry Soilless culture system (movable troughs) Small honeybee hives Better tasting cultivars Cultivar information (environmental physiology and photoperiodic responses) June-bearing cultivars + flowering control 24. Temperature x photoperiod general responses of strawberry Type Average Temperature June- bearing < 5C (41F) 5 12C (41-54F) 12 26C (54-79F) > 26C (>79F) No flower induction (dormancy) Flower induction under all photoperiods Short day (8-13 h) promotes flower induction No flower induction (critical temp depending on cultivars) Ever- bearing < 5C (41F) 5 15C (41-59F) 15 30C (59-86F) > 30C (>86F) No flower induction (dormancy) Flower induction under all photoperiods Flower induction under all photoperiods, but number of flowers increases under longer day Flower induction is suppressed. Strawberry production manual (Saga Prefecture AES) 25. Website: http://cals.arizona.edu/strawberry YouTube: Strawberry Sunrise in Arizona http://www.youtube.com/watch?feature=player_embedded&v=C1oSypOSrfU AZ Strawberry Days (Dec & Feb) K-12 Events (Nov & Apr) Outreach activities 26. Industries in News Windset Farms (Delta, BC) announced that they introduced greenhouse grown strawberries (3/25/2014, The Packer) La Frissonnante greenhouse (Quebec) will expand hydroponic strawberry production for exclusive sales to a major grocery chain, Metro Inc. (4/23/2014, CNW) A new 10-acre organic hydroponics GH in San Quintn, Mexico No Arizona greenhouses yet http://cnw.en.mediaroom.com http://elvigia.net 27. Acknowledgment UA hydroponic strawberry project is funded by a grant from the Walmart Foundation and administered by the University of Arkansas System Division of Agriculture Center for Agricultural and Rural Sustainability. U of AZ Project Team Chieri Kubota Mark Kroggel Myles Lewis Karla Garcia Cabello Michael Whalen Advisory Ian Justus Kelly Young Masami Ishikara Seiji Matsuda Collaborators Mike Evans Shoko Hikosaka