By Richard Jauron
In order to obtain the highest quality fruit, apples, apricots, peaches, pears, and plums must be harvested at the proper stage of maturity. Once harvested, proper storage is necessary to maximize storage life.
The harvest period for apples varies from one cultivar to another. For example, ‘Jonathan’ apples are normally harvested in mid to late September. The harvest season for ‘Red Delicious’ apples is normally late September to early October. However, the harvest period for apple cultivars is strongly influenced by weather conditions during the growing season. Gardeners, therefore, should base the harvest time on the maturity of the apples rather than a specific calendar date.
There are several indicators of apple maturity. Mature apples are firm, crisp, juicy, well colored, and have developed the characteristic flavor of the cultivar. Red color alone is not a reliable indicator of maturity. ‘Red Delicious’ apples, for example, often turn red before the fruit are mature. Fruit harvested too early are astringent, sour, starchy, and poorly flavored. Apples harvested too late are soft and mushy.
When harvesting apples, pick and handle the fruit carefully to prevent unnecessary damage. Sort through the apples during harvest. Remove and promptly use bruised or cut apples. Also, remove apples which exhibit insect and disease problems. Separate the apples by size. Use the largest apples first as they don’t store as well as smaller fruit.
Once harvested and sorted, store the undamaged apples immediately. The temperature and relative humidity during storage are critical for maximum storage life. Proper storage conditions for apples are a temperature near 32 degrees Fahrenheit and a relative humidity between 90 and 95 percent. Apple cultivars, such as ‘Red Delicious,’ stored under optimum conditions may be stored up to 3 to 5 months.
Harvest apricots when the fruit develop their characteristic color and begin to soften. When ripe, the fruit of ‘Moongold’ are golden yellow. The ripe fruit of ‘Sungold’ and ‘Moorpark’ are yellow with an orangish red blush.
Handle the fruit carefully to prevent bruising. Ideal storage conditions for apricots are a temperature near 32 degrees Fahrenheit and a relative humidity of 90 to 95 percent. Properly stored fruit have a storage life of 1 to 2 weeks.
Harvest peaches when the base or ground color changes from green to cream or light yellow. (Most peach cultivars develop a reddish blush. However, the reddish coloration is not a good indicator of maturity.) Firmness is another sign of maturity. Ripe fruit are slightly less firm. Firmness can be determined by gently squeezing a fruit with your fingers. If a fruit gives slightly, it is ready to harvest.
When harvesting, handle the fruit carefully to prevent bruising. Store peaches immediately at a temperature of 32 degrees Fahrenheit and a relative humidity of 90 to 95 percent. Peaches can be successfully stored for 2 to 3 weeks.
Most pears grown in Iowa are of European origin or European pears. Popular cultivars include ‘Summercrisp,’ ‘Moonglow,’ ‘Barlett,’ and ‘Kieffer.’ European pears should not be allowed to ripen on the tree. If fruit are left on the tree to ripen, stone cells develop in the fruit, giving the pears a pears on a tree branchgritty texture. Tree-ripened fruit are also poorly flavored. Harvest European pears when the color of the fruit changes from a deep green to yellow green. Also, the small spots (lenticels) on the fruit surface change from white to brown. The fruit will still be firm, not soft, at harvest.
For immediate consumption, ripen European pears at room temperature. The ripening process should take 7 to 10 days. To speed up ripening, place the pears in a tightly sealed paper bag. The fruit give off ethylene gas, which accumulates in the bag and promotes ripening.
For long-term storage, refrigerate unripe pears at a temperature of 32 to 35 degrees Fahrenheit. European pears may be stored for 1 to 3 months. Remove stored fruit about one week prior to use.
Asian pears (sometimes referred to as apple pears because of their round shape and crisp, firm texture) can be successfully grown in the southern half of Iowa. Popular cultivars include ‘Chojuro,’ ‘Hosui,’ and ‘Shinseiki.’
Asian pears, unlike European pears, should be allowed to ripen on the tree. Color and taste are the best indicators of maturity. The skin color of most Asian pears changes from green to yellow when ripe. When the color change occurs, pick and sample a pear. Ripe fruit should be crisp, crunchy, and sweet. Harvest Asian pears when the fruit have the appropriate color and taste.
Asian pears can stored for 1 to 3 months at a temperature of 32 to 35 degrees Fahrenheit. However, Asian pears sometimes develop a strong, winy taste if stored for long periods
As plums approach maturity, the fruit develop their characteristic color. The fruit of European or domestic cultivars (‘Stanley,’ ‘Damson,’ and ‘Mount Royal’) change from green to greenish blue, then to dark blue or purple. The ripened fruit color of most hybrid plums (‘Underwood,’ ‘Alderman,’ ‘Toka,’ and ‘Superior’) varies from red to burgundy red. Color, however, should not be the sole basis for harvesting plums. As they ripen, plums begin to soften, especially at the tip end. They also develop their characteristic flavor.
Harvest and handle plums carefully. The fruit can be stored for approximately 2 to 3 weeks at a temperature of 32 degrees Fahrenheit and a relative humidity of 90 to 95 percent.
Approximate harvest times for tree fruit cultivars can be found in Pm-453 “Fruit Cultivars for Iowa.” Keep in mind that weather conditions during the growing season may hasten or delay fruit maturity.Source : iastate.edu