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Michael Reid, University of California, Davis Cai-Zhong Jiang, USDA-ARS, Davis.

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Presentation on theme: "Michael Reid, University of California, Davis Cai-Zhong Jiang, USDA-ARS, Davis."— Presentation transcript:

1 Michael Reid, University of California, Davis Cai-Zhong Jiang, USDA-ARS, Davis

2 Floriculture crops : Cut flowers, cut cultivated greens, foliage plants, potted flowering plants, annual bedding/garden plants, propagative floriculture material Nursery crops : Evergreens_broadleaf, coniferous, Trees_shade, flowering, Christmas, fruit and nut plants, transplants, shrubs and other ornamentals and propagation material Ornamental Industry

3 The California nursery and floriculture industry

4 Value of California’s agriculture Data from the California Department of Food and Agriculture.

5 Contrast with cookies

6 What’s the problem? Low per capita consumption of cut flowers – Holidays – Weddings – Funerals Very low personal use Low per capita consumption of cut flowers – Holidays – Weddings – Funerals Very low personal use

7 Purchases of Cut flowers (retail) per capita in 2002 (in NTD) Switzerland4000 Netherlands2400 Belgium1760 Germany1600 U.K.1600 Italy1320 France1320 Spain 760 Portugal 640 Poland 280 U.S. 200 Russia 120 Source, Flower Council of Holland

8 The postharvest problems Flowers are shipped long distances and stored for long times >25% product losses in marketing chain Flowers and potted plants don’t last long enough International market, strong competition Lower consumer satisfaction. Customers don’t return

9 Species and cultivar Temperature Damage and disease Water supply Ethylene and other PGRs Food supply Growth Factors affecting the postharvest life of ornamentals

10 Genetic difference in vase life among rose genotypes

11 Temperature - why is it important? Rate of deterioration  rate of respiration Faster respiration, shorter life Respiration increases exponentially with T

12 Roses held 5 days at different temperatures then 8 days in vase life room at 20⁰C 2.5 5 5 7.5 0 0 10 12.5

13 Temperature, respiration rate & vase life in stock flowers

14 Postharvest Disease Postharvest disease (primarily caused by gray mold (Botrytis cinerea) is a common cause of poor quality and shortened vase life

15 Disease control strategies Host Environment Pathogen The disease life cycle The disease triangle Disease

16 Disease control – the pathogen  Reduce spore load o sanitation in field, greenhouse, shed  Prevent spore germination o reduce condensation, injury, temperature  Prevent fungal entry o care in handling

17 Disease control - the host  Maintain in good condition, grow healthy plants, enhance physiological resistance.  Molecular biology-introduce resistance genes  Select resistant cultivars-variance is commonly observed  Treat with fungicides

18 Fungicides  Rely on synthetic chemical fungicides  Effective  Applied by dipping, in fogs  Development of resistance  Safety & environmental concerns

19 Sodium hypochlorite (NaOCl) A strong oxidizing agent with broad spectrum antimicrobial activity Active ingredient in household bleach Commonly used for reducing bacterial and fungal contamination on fruit and vegetable surfaces and in flower vase solutions

20 Using NaOCl to control Botrytis infection in cut rose

21 Optimal concentration of sodium hypochlorite for controlling botrytis on rose ‘Akito’ and ‘Gold Strike’ flowers

22 Water supply Plants are mostly water (80-90%) Loss of water causes – loss of quality – wilting – accelerated aging – (ethylene production)

23 Failure in water relations Water uptake < transpiration Xylem occlusion – Emboli – Hard water – Bacteria – Physiological plugs

24 Air emboli Recut under water Acidify the water Use warm (or cold) water Pressurize (20 cm H 2 O) Use a brief detergent dip

25 Water depth 20 cm 10 cm 5 cm Roses dehydrated 10% Recut Placed in different water depths Photograph taken after 4 hours

26 Bacterial contamination

27 The Problem Desiccation of potted plants Lack of proper watering At the retail level Control Training retail staff Treatments to close stomata Salt stress? ABA?

28 Chemical manipulation of ABA Level Well-watered NaCl ABA No water

29 Ethylene-dependent senescence  Carnation model system  Ethylene production prior to onset of natural senescence  Pollination accelerates ethylene production and senescence

30 1-MCP - a new ethylene inhibitor Ethylene 1-MCP Ed Sisler, NCSU Mimics ethylene, blocks the binding site Marketed for flowers as EthylBloc For fruits and vegetables as ‘SmartFresh’

31 Studies on environmental requirements Experiments to determine the best treatment conditions – concentration – temperature – time of MCP exposure – effective duration

32 1-MCP effects may be transient Day 1 Day 2 Day 3 Plants were treated with 1-MCP on day 0, then exposed to ethylene on days 1, 2 or 3

33 Other growth regulators Gibberellins retard leaf yellowing So do cytokinins Including thidiazuron, at very low concentrations (5 µM)

34 Thidiazuron A non-metabolized cytokinin analog Mode of action not yet clear – Reduced metabolism of native cytokinins? – Triggers the cytokinin response mechanism?

35 At higher concentrations (500 µM) TDZ improves Iris opening and vase life Plus TDZNo TDZ Can stimulate opening o f a second flower

36 Cyclamen after 2 months display ControlTDZ

37 Food Flowers need food to grow and develop Sugar (sucrose, glucose, or fructose) provides all that is needed Vase solutions should contain 1.5 – 3% sugar Bacteria like sugar too – use a bactericide

38 Effect of sucrose pulse on Eustoma

39 Continued growth Growth away from gravity Growth towards light Can cause quality loss – snapdragons, tulip, red-hot poker Control – temperature – orientation – Chemicals Naphthylphthalamic acid Inhibits auxin transport

40 Effect of NPA pretreatment

41 Acknowledgments USDA BARD_Israel American Floral Endowment Joseph H. Hill Memorial Foundation Mellano & Company Kitayama Brothers Goldsmith Seeds Rosen Tantau

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