John R. Pyzner | 4/30/2005 12:55:08 AM
Recognizing the proper stage to pick a peach to obtain its highest quality is important, according to LSU AgCenter horticulturist Dr. John Pyzner. Ripening dates of peaches vary with varieties.
Florida King, Bicentennial and Regal normally ripen in May in Louisiana. Dixieland, Ruston Red and Redglobe usually ripen in July. Weather conditions may move the ripening period a week or two earlier or later.
Pyzner points out that uneven ripening of fruit on a tree may spread the ripening period over a couple of weeks. Each picking of the fruit should be selective, removing fruit only at the desired ripeness stage. Color and firmness are the two most useful factors in selecting fruit for picking.
A final swell stage occurs shortly before ripening when the fruit rapidly increases in size. In this stage, a red blush develops over the green under-color of the fruit.
Pyzner says, however, that the red blush or over-color should not be used as an indicator of ripeness, because the degree of red varies tremendously among and within peach varieties. In fact, peach varieties such as La Gold and Ouachita Gold have little red over-color on fruit in the interior shaded areas of the tree.
The most important color change indicator of ripeness is the change in under-color of the fruit from green to yellow. This color is most apparent on the stem end of the fruit. This stage is called firm-ripe. A slight cushioning of firmness of the fruit usually can be felt.
Firm-ripe is the stage commercial peach growers usually harvest their fruit. Fruit at this stage will develop good flavor, and the fruit will be firm enough to handle and ship without bruising. Fruit at this stage usually can be kept in cold storage a couple of weeks. Fruit stored more than two weeks sometimes loses quality. Fruit harvest at firm-ripe can be used by the home gardener to send to friends or relatives or to store excess fruit for a short time under refrigeration. Use caution, however, because frost-free refrigerators have a drying cycle that can rapidly dry peach fruit.
Home gardeners usually like to harvest their peaches at soft-ripe, which normally occurs a day or two after firm-ripe. Fruit at this stage has excellent flavor and is juicy. Unfortunately, soft-ripe fruit has limited availability because it cannot be handled or shipped without bruising. Soft-ripe fruit must be sold or used immediately.
Pyzner recommends harvesting in the early morning when temperatures are low. Transfer the fruit to a cool storage or packing area as quickly as possible to avoid prolonged exposure to the sun, which stimulates post-harvest ripening.
For related horticulture topics, look for Gardening and Get It Growing links in the Feature section of the LSU AgCenter Web site: www.lsuagcenter.com.