Articles
EFFECT OF ETHEPHON AT A HIGH CONCENTRATION ON THE RIPENING OF ‘HAYWARD’ KIWIFRUIT ON THE VINE
We now have investigated a higher concentration application of ethephon.
When 500 ppm of ethephon (dissolved in 50% ethanol) was applied about 3 weeks before commercial harvest, the fruits became edible about 2 weeks after treatment.
The Brix, flesh firmness, and titratable acidity of the fruits respectively were 13.5%, 0.6 kg.cm-2 and 1.0%. But slight differences in fruit ripening occured in individual fruits.
Ethylene evolution by the fruits peaked 2 days after treatment, then peaked again at 16 days about 2 fold the original peak.
The ACC content decreased gradually.
EFE activity showed a slight increase immediately after treatment, then on and after 10 days after the treatment increased rapidly.
The ABA content decreased gradually.
The fruits started to drop 10 days after treatment.
The above findings indicate that an ethephon application of 500 ppm effectively induces autocatalytic ethylene synthesis by kiwifruits and that it is a practical concentration to use to promote fruit ripening on the vine if attention is paid to the harvest time.