CCF Post-Harvest Care & Floral Preservation 2 — Questions and Answers
Question 1: What is ethylene gas and why is it significant in floral post-harvest management?
- A refrigerant used in commercial floral coolers
- A natural plant hormone that accelerates flower aging and senescence (Correct answer)
- A synthetic preservative chemical applied to cut stems
- A pesticide commonly used on greenhouse flowers
Correct answer: A natural plant hormone that accelerates flower aging and senescence
Ethylene is a natural plant hormone that triggers ripening and senescence; exposure to even low concentrations can dramatically reduce the vase life of sensitive flowers.
Question 2: Which group of cut flowers is most sensitive to ethylene gas exposure?
- Sunflowers and dahlias
- Tropical foliage and succulents
- Carnations, roses, and alstroemeria (Correct answer)
- Dried flowers and preserved greens
Correct answer: Carnations, roses, and alstroemeria
Carnations, roses, and alstroemeria are among the most ethylene-sensitive cut flowers; exposure causes rapid petal drop, wilting, and color loss.
Question 3: What role does the sugar component in a three-part floral preservative play?
- Provides carbohydrate nutrition to sustain continued flower development (Correct answer)
- Lowers the pH of vase water to inhibit bacteria
- Acts as a biocide to kill microorganisms
- Reduces the water temperature in the vase
Correct answer: Provides carbohydrate nutrition to sustain continued flower development
Sugar supplies carbohydrates that fuel petal development, maintain color, and replace the energy the flower can no longer produce via photosynthesis after being cut.
Question 4: What is botrytis and how does it affect cut flowers in storage?
- A beneficial mold that slows respiration and extends shelf life
- A bacterial wilt that travels through stem vascular tissue
- A virus that causes color-breaking streaks in petals
- A gray fungal disease that causes spots, decay, and petal collapse (Correct answer)
Correct answer: A gray fungal disease that causes spots, decay, and petal collapse
Botrytis cinerea is a gray mold fungus that thrives in high-humidity storage, producing spores that cause brown spots and rapid petal and foliage decay.
Question 5: Why should cut flowers be stored away from fresh fruits and vegetables in a floral cooler?
- Fruits absorb moisture from flower petals
- Ripening fruits emit ethylene gas that accelerates flower senescence (Correct answer)
- Vegetables compete inefficiently for cooler airflow
- Fruits introduce bacterial contamination into flower water
Correct answer: Ripening fruits emit ethylene gas that accelerates flower senescence
Ripening fruits are high ethylene producers; even brief co-storage with ethylene-sensitive flowers can significantly reduce their vase life.
Question 6: What is the correct post-harvest handling technique for hollow-stemmed flowers such as delphiniums to ensure full stem hydration?
- Turn the stem upside down, fill the hollow cavity with water, plug with cotton, then condition normally in a bucket (Correct answer)
- Place stems directly in dry floral foam without water
- Sear the hollow stem end with a flame to create a seal
- Submerge stems fully in ice water for one hour
Correct answer: Turn the stem upside down, fill the hollow cavity with water, plug with cotton, then condition normally in a bucket
Inverting hollow stems, filling them with water, and plugging them with cotton ensures the entire stem length is hydrated before conditioning, preventing air pockets.
Question 7: What pH range is generally recommended for vase water or floral preservative solutions to optimize stem water uptake and inhibit bacteria?
- pH 3.0-3.5 (strongly acidic)
- pH 3.5-4.5 (mildly acidic) (Correct answer)
- pH 7.0 (neutral)
- pH 8.0-9.0 (alkaline)
Correct answer: pH 3.5-4.5 (mildly acidic)
A mildly acidic pH of 3.5-4.5 reduces bacterial populations and improves the efficiency of water movement through stem xylem vessels.
CCF Post-Harvest Care & Floral Preservation 2
What is ethylene gas and why is it significant in floral post-harvest management?