This section is from the book "Manual Of Tropical And Subtropical Fruits", by Wilson Popenoe. Also available from Amazon: Manual Of Tropical And Subtropical Fruits.
In the tropics papayas are in season during a large part of the year and the yield is enormous, a single plant bearing in the course of its life (not more than a few years) a hundred or more immense fruits. In Florida the season extends from December to June, with a few fruits ripening at other times. Higgins and Holt say: "The first ripe fruits may be expected (in Hawaii) in about a year from the time when the plants are set in the orchard or garden, and thereafter fruits and flowers in all stages of development may be in evidence at all times of the year. In the cool season the fruits are slow in ripening, thus causing a short crop and high prices for a month or two."
1 Journal of Heredity, May, 1916.
Sometimes the fruits are produced in such abundance that it is necessary to thin them in order to avoid their remaining small in size or becoming malformed by the pressure of neighboring fruits. Thinning should be done when the fruits are rather small.
If the fruits are to be sent to market they should be picked as soon as the surface begins to turn yellow. "Certain varieties become ripe enough for serving while showing little yellow coloring." It is difficult to ship the fully ripe fruit, since it is large, heavy, and has no firm outer covering, but only a thin membranous skin, to protect it. For this reason papayas must be shipped before they are fully ripe, and even then great care is necessary. Shipments have been made from Hawaii to San Francisco in cold storage with good results. When shipped from southern Florida to New York by express, the percentage of loss is usually large, unless the fruit is picked while still green; and in the latter case it does not ripen properly after reaching the market. It is advised to encase the fruits in cylinders of corrugated strawboard, and pack them in single-tier cases holding four to six fruits.