PACKAGING OF POTTED PLANTS

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Horatio Cook
5 years ago
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1 PACKAGING OF POTTED PLANTS

2 OUTLINE 1. Water loss and wilting 2. Packaging of potted plants 2.1. Closed bags 2.2. Sleeves Comparison of commercial sleeves Sleeve design

3 WATER LOSS AND WILTING

4 WATER LOSS AND WILTING Transpiration +evaporation Evaporation (E) Wilting time = Evapotranspiration (ET) m water rate of (ET + E) Depends on: Genotype Plant size Stomatal conductance Temperature Relative humidity (RH) Light Air velocity

5 WATER LOSS AND WILTING Transpiration +evaporation Evaporation (E) Wilting time = Evapotranspiration (ET) m water rate of (ET + E) Depends on: Genotype Plant size Stomatal conductance Temperature Relative humidity (RH) Light Air velocity

6 WATER LOSS AND WILTING Control of water loss: 1. Increase mass of water - by increasing pot size and/or peat water content disadvantages: extra costs, physiological disorders due to flooding stress 2. Decrease stomatal conductance by changing growing conditions or by using chemical treatments to close stomata (Vaporseal, ABA, etc) disadvantages: extra costs, physiological disorders or no efficiency

7 WATER LOSS AND WILTING Control of water loss: 3. Cooling store at low temperature (dicrease ET by decreasing vapor pressure difference) Hard to implement in whole chain Disadvantages: extra costs and risk for condensation 4. Packaging create optimal microclimate within package that can decrease ET. Disadvantages: extra cost? and risk for disease development

8 PACKAGING OF POTTED PLANTS

9 PACKAGING: THEORY RHenvironment RHpackage RHenvironment Film barrier Steady state ET + E = Water vapor out Film barrier properties depend on: Geometry Film WVTR* Perforations *WVTR Water vapor transmission rate

10 PACKAGING: THEORY Film material Film thickness - WVTR Area - WV release rate Perforation number and/or diameter - WV release rate Fact: Open top of the sleeve is very BIG perforation WVTR at 23 C and 100% RH (g m ² d ¹) Bi-axially oriented polypropylene (OPP) 40 µm 1.2 Polylactic acid (PLA) 40 µm 90.7 NatureflexTM (NFX) 30 µm 304

11 PACKAGING: THEORY Non-uniform RH distribution High air velocity No light Low air velocity 12 h day light

12 PACKAGING OF POTTED PLANTS 1. Closed bag 2. Sleeve

13 CLOSED BAG Advantages: 1. Absence of big sleeve - perforation Low WV release rate long time until wilting Wilting limit 2. Absence of direct contact with food, environment, insects, etc. 3. Increased ornamental value

14 CLOSED BAG Disadvantages: 1. Risk for disease development 2. Requires extra equipment and/or man-power 3. Can be more expensive than sleeve

15 CLOSED BAG FOR ROSE OPP bag most efficient but high risk for disease development Wilting limit PLA bag second most efficient For mini roses times lower weight loss than commercial sleeve For big roses (10.5) times lower weight loss than commercial sleeve Close to optimal packaging

16 CLOSED PLA BAGS FOR ROSES PLA Commercial Nonbag sleeve packed PLA Commercial Nonbag sleeve packed 5 C 89% RH 16 C 96% RH 16 C 81% RH 23 C 89% RH

17 CLOSED BAGS FOR CAMPANULA

18 CLOSED BAG: DESIGN 1. Only plants tolerant to high RH Wilting limit 2. Desired shelf-life can be achieved by optimizing WVTR and perforations 3. Promising solution but hard to implement

19 PACKAGING OF POTTED PLANTS 1. Closed bag 2. Sleeve

20 COMPARISON OF COMMERCIAL SLEEVES Plant: Campanula (10.5) Storage: 4 days at 5, 16 or 23 C (in sleeve, no irrigation) 7 days at 20 C (in sleeve, no irrigation) 6 days at 20 C (unpacked, irrigated) Results: Sleeve A higher weight loss than Sleeve B No difference in plant quality between Sleeve A and B (5 and 16 C) At 23 C severe disease developemnt in Sleeve B

21 PLANT QUALITY AFTER 17 DAYS Sleeve A Sleeve B Non-packed

22 SLEEVE DESIGN: WEIGHT LOSS (CAMPANULA) 4 days at 23 C and 7 days at 20 C

23 SLEEVE DESIGN: EXAMPLE - = = 5.5 g perf. 31% more weight loss - = = 2.5 g perf. 14% more weight loss

SLEEVE DESIGN: EXAMPLE Predited weight loss 106.2 + 5.5 2 + 2.5 2 = 122.

24 SLEEVE DESIGN: EXAMPLE Predited weight loss = g Actual weight loss g = g g = g g

25 SLEEVE DESIGN 1. Select one cultivar 2. Determine area with the highest RH (where disease is developing) 3. Test sleeves with different number, size and placement of perforations and find optimal combination. 4. Test optimal sleeve on plant with different disease levels. If plant is already diseased apply more perforations. 5. Test optimal sleeve on other cultivars. Storage time RH Disease Weight loss

26 QUESTIONS In collaboration with, ElmerPrint, Gartneriet PKM, Rosa Danica, Gartneriet Thoruplund, By Growers

Transport Systems in Plants and Animals

Transport Systems in Plants and Animals Mark Scheme Level Subject Exam Board Unit Topic Difficulty Level Booklet GCSE Biology AQA B3 Transport Systems in Plants and Animals Bronze Level Mark Scheme Time