Postharvest Handling of Citrus
In tropical and subtropical countries, the development of the fruit is affected by the temperature. Maturity of the rind and maturity of the flesh of the fruit are not synchronized. The fruit is edible even when the rind still remains green.
Mature fruit vary in size, even those on the same tree. With sweet oranges such as Valencia or Liucheng, harvesting should begin with the smaller fruit which mature first.
With mandarins such as Ponkan, it is the end of the fruit furthest from the stem which turns yellow first. Harvesting should begin with the large fruit. Smaller fruit, or those which are slow to turn color, should be harvested later on in the season.
Time of Day for Harvest
It is best to harvest citrus on a clear, sunny day with low humidity. The fruit should be harvested as soon as the dew has evaporated. On a cloudy day, the fruit should be harvested in the afternoon. Fruit should not be harvested at all on a rainy day.