Step 1: Understand the harvest stage:
The stage of harvest decides how long a cut flower lasts.
Each flower has a correct stage, usually bud or half-open, when it should be cut.
Step 2: Define over-mature stage:
An over-mature flower is one that has opened fully or even begun to age before it is cut.
Step 3: List the ill-effects:
Such flowers wilt very fast.
Petals may fall off during packing and transport.
The flowers are easily bruised and are more sensitive to ethylene.
The result is a very short vase life.
Final Answer:
Harvesting flowers at an over-mature stage reduces their vase life, because they wilt quickly and shed petals.