The fully mature fruit have the best flavour, but a short shelf-life. Hence, they should be harvested when they are about three-quarters yellow or purple. Immature fruits do not ripen properly after harvest. The purple passion fruit, forma edulis, may become reddish and shrivel if harvested too immature.
The passion fruit vine, especially the Yellow, is fast-growing and will begin to bear in 1 to 2 years. Ripening occurs 70 to 80 days after pollination. A passionfruit orchard may have a economic life span of 3-5 years. There are two major seasons of production, June to August and November to January. The first season may extend from May to October. Fruits are harvested when they have dropped to the ground. Green or immature fruits should not be picked off the vine as they will not ripen, they will also be off flavored and have a higher concentration of cyanogenic glycosides (a toxin produced by the vine). Fruits fall after ripening on the vines and are picked up from the ground 2 to 3 times weekly. Fruit yield is 7-10 t/ha or more. Yields up to 40 t/ha have been reported.
Seedlings set in the spring will spend most of the first season in the field in vigorous vegetative growth, although a few flowers and fruit may appear in late summer on vines of the yellow passion fruit. Vines grown from cuttings flower more profusely and set more fruit the first year in the field than do seedlings, but cutting-grown vines are more expensive to produce and often less vigorous than seedlings. Furthermore, one must exercise great caution to keep the plants from which cuttings are taken free of disease, a task that is not necessary when seedlings are used.
Approximately 3.5-7 kg of fruit per plant is likely to be the best production that can be expected of the yellow passion fruit in Florida until more productive cultivars become available. With these levels of production and a spacing of 3 x 4.5m, one might optimistically expect a production of 2.5-5 t/ha of yellow passion fruit here. At best, the purple passion fruit would likely to produce yields only as great. Insufficient data are available to predict yields of the giant granadilla.
The entire crop of purple passion in fruit and the early crop of the yellow form matures in late spring and early summer. Then the vines grow vegetatively and most do not flower when days are longest, from about June 21 to July 4. Yellow passion fruit vines begin the season's second flowering in the latter half of July, usually peaking in mid-August and continuing until October or November. Fruit set from the second flowering ripens from September through early February.
Developing passion fruit remains green until fully mature, then change colors rapidly within a few days. Both yellow and purple fruits drop to the ground when ripe. The fruit should not be harvested until it drops, because fruit picked from the vine has an unripe "woody" taste. In some regions, the soil beneath the vines is kept weed free and the newly fallen fruit is collected once or twice a week for market. Summer fruit is better collected daily because of higher temperatures and the danger of sun-scalding.
The passion vine is a short-lived perennial. Some yellow passion fruit vines have persisted in the field for 10 years, but this is exceptional. A more realistic life expectation is 3-5 years. A vine that appears to have excessive deadwood may have lost so much vigor that it should be removed and replaced with a young, healthy plant.
