Crop of the Week: Grapefruit

• Yuma County produced about 250,000 cartons of grapefruit on 150 acres in 2010 valued at more than $155,000. World production of grapefruit is almost 6 million tons; the United States produces over 60 percent of this total.

• The grapefruit got its name from the way it grows in clusters like grapes on the tree. There is no mistaking a grapefruit tree — they are large with glossy, dark green leaves, and the fruit hangs in clusters. Some mature grapefruit trees can yield up to 1,500 pounds of fruit in a season.

• Grapefruit comes in two varieties: white and pink. Pink grapefruit gets its color from carotenoids (carotene) and contains over 50 times the carotenoid of white grapefruit. In the body, carotenoids are partially converted to vitamin A, so eating pink grapefruit adds vitamin A to your diet. Vitamin A is an antioxidant that is required in the diet for good growth, skin development and the maintenance of peripheral vision.

• Grapefruit offers about 69 percent of the recommended daily allowance for vitamin C. It also is a good source of potassium and pectin, a soluble fiber effective in lowering cholesterol levels.

• A grapefruit is 75 percent juice. One medium grapefruit will give you two-thirds of a cup of fresh-squeezed juice. Grapefruit juice freshly squeezed and stored covered in the refrigerator will retain 98 percent of its vitamin C for up to a week.

• Store grapefruit at room temperature up to a week, or up to eight weeks in a refrigerator. You can eat grapefruit just like an orange by peeling it and dividing it into segments. Each medium grapefruit has between 10 to 12 sections.

• Since the early part of the 20th century, mutant strains of white grapefruit have appeared with pink to slightly reddish color. They have been propagated by citrus breeders into several strains of grapefruit that are now best known as the Ruby Red.

• Pummelos, the largest of the citrus fruit varieties, are also called Chinese grapefruit. The West Indies were the point of origin for grapefruit, probably as a natural cross between the pummelo and a sweet orange, and was later propagated in 1830 as the seedy Duncan variety. The first seedless grapefruit variety was the Marsh white, which through bud mutation was the progenitor of the pink varieties. The grapefruit is readily crossed with other members of the citrus genus. The tangelo, a Florida juice fruit, was produced by fertilization of grapefruit flowers with mandarin orange pollen.

• Generally, a grapefruit does not “ripen” in the normal sense of the word. Rather, it matures to good eating quality. Yuma grapefruit will usually achieve maturity in late October, although the peel color will likely still be quite green. The longer the fruit remains on tree, the larger it becomes and the sweeter it becomes. A grapefruit holds very well on the tree, so fruit can be harvested as needed from late October through May.

Source: Kurt Nolte is an agriculture agent and Yuma County Cooperative Extension director. He can be reached at knolte@cals.arizona.edu or 726-3904.