People should dispose of papaya seeds properly if they are uncertain about the sources of the plant they are from, organic farmers advise.
They say proper disposal is vital to control the proliferation of genetically modified papaya trees and minimise the risk of contamination.
'Many people love papaya and sometimes they like to plant their own with the seeds left from the fruit. But they might release more GM papayas unknowingly,' Fan Ling grower Augustine Lo Yat-man said.
Contamination occurs when the pollen of a male GM papaya is carried to the flower of a female non-GM plant by insects or the wind.
Scientists said this cross-pollination would not alter the plant itself or create genetically modified fruit, but the seeds could be changed. Trees grown from these seeds and their fruit would contain modified genes.
To avoid contamination, natural papaya plants should be planted with a buffer area between them and modified trees. Generally a kilometre is enough as bees seldom travel further. But this is difficult in Hong Kong where farms are so close together.
Distinguishing GM from non-GM papaya is difficult, if not impossible. Farmers cannot find out if their papaya are contaminated without a laboratory test costing HK$1,000.