Postharvest Short Course 2014 Ornamentals part1 · Daylily, Tulips, Iris, Freesias, Daffodils...
20
6/18/2014 1 Cai‐Zhong Jiang, USDA‐ARS, Davis Michael Reid, University of California, Davis • Floriculture crops : cut flowers, cut cultivated greens, foliage plants, potted flowering plants, annual bedding/garden plants, propagative floriculture materials • Nursery crops : Evergreens_broadleaf, Trees_shade, flowering, Christmas trees, fruit and nut plants, transplants, shrubs and other ornamentals and propagation materials Ornamental Industry
Transcript of Postharvest Short Course 2014 Ornamentals part1 · Daylily, Tulips, Iris, Freesias, Daffodils...
6/18/2014
1
Cai‐Zhong Jiang, USDA‐ARS, DavisMichael Reid, University of California, Davis
• Floriculture crops :
cut flowers, cut cultivated greens, foliage plants, potted flowering plants, annual bedding/garden plants, propagative floriculture materials
• Nursery crops :
Evergreens_broadleaf, Trees_shade, flowering, Christmas trees, fruit and nut plants, transplants, shrubs and other ornamentals and propagation materials
Ornamental Industry
6/18/2014
2
Value of California’s agriculture
Data from the California Department of Food and Agriculture.
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
6/18/2014
3
Postharvest science
• Goal ‐ reduce losses, increase quality, expand markets
• Understand factors involved in postharvest losses
• Develop better technologies to reduce losses
• Temperature• Disease• Water supply• Ethylene• Food supply
Factors affecting the postharvest life of ornamentals
6/18/2014
4
Temperature ‐ why is it important?
• Perishable products are alive
• Flowers have high respiration rates
• Vase life is directly correlated with the respiration rate
y = 0.0012x4 - 0.0619x3 + 1.2003x2 - 3.6913x + 25.509
R2 = 0.9974
0
50
100
150
200
250
300
350
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Temperature (C)
Res
pir
atio
n(m
lC
O2
/kg
hr) y = -0.0299x + 7.1564
R2 = 0.9426
0
1
2
3
4
5
6
7
8
9
0 50 100 150 200 250
Total CO2 respired during storage (x100) ml CO2/kg
Vas
e lif
e af
ter
sto
rag
e (d
ays)
Temperature, respiration rate & vase life in stock flowers
Example ‐ Carnations
• Last for five days at 20 C• Q10= 4• Life = 20 days at 10 C• Life = 80 days at 0 C• We can store carnations for 10 weeks
Tulips after dry storage at different temperature
6/18/2014
5
Snapdragon after dry storage at different temperature
Effect of temperatureLilies stored 5 days, 2 days in vase life room
2.52.5 55 7.57.500 1010 12.512.5 1515
6/18/2014
6
Improving the cold chainTransportation at low temperatures reduces respiration &
improves the subsequent life of cut flowers
3737 4141 46463232 5050 5555
Advantages of decreased temperature in handling flowers
1. respiration2. transpiration
3. dehydration4. ethylene production5. ethylene susceptibility6. condensation
7. disease growth (Botrytis)8. bending9. flower development10. color loss/yellowing
6/18/2014
7
Postharvest Disease
Postharvest disease (primarily caused by gray mold (Botrytis cinerea) is a common cause of poor quality and shortened vase
life
Botrytis cinerea
Ubiquitous and necrotrophic fungus
Affects numerous agricultural crops
Causal agent of gray mold disease
Brings about severe economic losses
Pre‐harvest and postharvest infection
6/18/2014
8
Disease control strategies
Host
Environment
Pathogen
The disease life cycle
The disease triangle
Disease
Disease control
Reduce spore load
o sanitation in field, greenhouse, shed
Prevent spore germination
o reduce condensation, injury, temperature
Prevent fungal entry
o care in handling
6/18/2014
9
Disease control Temperature
Humidity
o prevent condensation
Atmosphere
o high CO2, CO/low O2
Fungicides
Rely on synthetic chemical fungicides
Effective Applied by dipping, in fogs Development of resistance Safety & environmental
concerns
6/18/2014
10
Alternative or Non‐Conventional Chemical Control
• Active ingredient in household bleach
• A strong oxidizing agent with broad spectrum antimicrobial activity
• Commonly used for reducing bacterial and fungal contamination on fruit and vegetable surfaces and in flower vase solutions
Sodium hypochlorite (NaOCl)
Optimal concentration of sodium hypochlorite for controlling botrytis on rose ‘Akito’ and ‘Gold Strike’
flowers
No dip 0 100 200 400 800
Bo
tryt
is in
cid
en
ce (
%)
0
20
40
60
80
100 'Akito' 'Gold Strike'
NaOCl concentration (µL L-1)
aa
a
a
b
bb
bb
b b b
Flowers were dipped in 0, 100, 200, 400 or 800 µL L‐1 (ppm) NaOCl (provided by Clorox® Ultra bleach solution) for 10 s.
6/18/2014
11
Optimal treatment time of sodium hypochlorite for controlling botrytis on rose ‘Gold Strike’ flowers
Dip treatment time (s)
0 1 5 10 30
Bot
rytis
inci
denc
e (%
)
0
20
40
60
80
100 Water NaOCl
aa
a
a
aa
b b b b
Flowers were dipped in 0 (water) or 200 µL L‐1 (ppm) NaOCl (provided by Clorox®
Ultra bleach solution) for 1, 5, 10 or 30 s at 20°C.
Using NaOCl to control Botrytis infection in cut rose
6/18/2014
12
Water supply
• Plants are mostly water (80‐90%)
• Loss of water causes
– loss of quality
– wilting
– accelerated aging
– (ethylene production)
Water supply
• How do plants get water?
• Evaporation from leaves (transpiration) creates tension in the conducting system (xylem)
• Tension drags water from the soil or vase solution
6/18/2014
13
Water supply
• Why do cut flowers wilt?– Air embolism
– Bacterial contamination
• Why do potted plants wilt?– Drought
– Waterlogging
6/18/2014
14
Air embolism blocks vessels
• Recut under water• Acidify the water• Use warm (or cold) water• Pressurize (20 cm H2O)• Use a brief detergent dip
• Recut under water• Acidify the water• Use warm (or cold) water• Pressurize (20 cm H2O)• Use a brief detergent dip
Minimizing Air emboli
6/18/2014
15
• Use a preservative• Clean white buckets• Use a preservative• Clean white buckets
Maintaining water supply
No ClO2 Plus ClO2
The simple question:Would you drink that water, from that bucket?
The simple question:Would you drink that water, from that bucket?
6/18/2014
16
Ethylene dependent Ethylene production prior to onset of
natural senescence
Pollination accelerates ethylene production and senescence
Carnation, roses, snapdragon,
Ethylene independent flowers: Low or no ethylene production Pollination has no effect on longevityEthylene inhibitors do not extend lifeShort‐lived and important crops
Daylily, Tulips, Iris, Freesias, Daffodils
Response to ethylene treatments
Rose plants were initially stored at 0C for 7 days and then treated with 2.5 ppm of ethylene for 48 hours.
6/18/2014
17
STS
Benefits of 1‐MCP
6/18/2014
18
• The mutant receptor, etr1-1, identified from Arabidopsis has been shown to be unable to bind ethylene and confers ethylene insensitivity.
• Expression of Arabidopsis etr1-1 in other species, including carnation, leads to delayed floral senescence.
Using biotechnology to block ethylene signaling
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
6/18/2014
19
Food
Sugar pulsing to provide food
6/18/2014
20
• Temperature• Disease
• Water supply
• Ethylene
• Food supply
Factors affecting the postharvest life of ornamentals
