Seedlings may ordinarily take 4 to 14 years to come into bearing, though certain precocious cultivars may begin to bear in 2 1/2 to 3 1/2 years. The jackfruit is a fairly rapid grower, reaching 17.5 m in height and 70cm around the trunk in 20 years in Ceylon. Fruit yield varies greatly between regions. In India, the expected yield varies according to the region - Kerala: 250-300 fruits/plant.; Karnataka: 50-250 fruits/plant. In India, a mature tree produces up to 700 fruits per year. Each fruit weighs from 0.5 kg up to as high as 50 kg. On average one can expect a yield of on average 10 t/ha. Potential yields of 100-200 fruits per tree per year have been estimated. For example, in India a good annual yield is considered to be 150 large fruits per tree (Morton 1987). Actual yields of mature trees are 70-100 kg of fruit/tree/yr depending on variety, cultural practice, and environmental factors (Soepadmo 1992). However, productivity declines with age.

Jackfruits mature 3 to 8 months from flowering. When mature, there is usually a change of fruit color from light green to yellow-brown. The colour of fruit becomes pale and develops a strong aroma. Spines become flattened and wider, yield to moderate pressure, and there is a dull, hollow sound when the fruit is tapped.

Fruits are harvested by cutting off the footstalk and placed in baskets which are carefully lowered from the tree by a rope, without dropping on the ground which may damage them. The portion of the stalk attached to the fruits helps in handling. Fruits are harvested in the morning hours while temperatures are low and transfer them immediately to a well-ventilated shed. Ripe fruits turn brown and deteriorate rather quickly.