Kinnow, a King-Willowleaf mandarin hybrid, was originally developed at the University of California Research Center, Riverside in 1915 and released in 1935. It is the most widely-planted mandarin in Pakistan. The tree grows vigorously, is cold-resistant and has an upright form, with a strong tendency to alternate bearing (the tendency of fruit trees to produce a heavy crop one year followed by a light crop or no crop the following year). The fruit is oblate with a smooth orange rind that does not peel especially well for a mandarin. The flesh is orange, seedy, and has a rich distinctive flavor. Kinnow matures mid-season and holds well on the tree.