Peach trees grow best in temperate climates with well-drained soil and sloped land for good air circulation. Fields previously planted with soybeans or alfalfa are not recommended due to soil viruses. New trees will not bear fruit for 3 years, but most enjoy an average lifespan of 15 to 20 years.
Mature trees can reach heights and widths of 25 feet and require ample chill hours (ranging from 800 to 1,500 hours) before the onset of warm weather blossoming can begin.
Excess flowers and young fruit should be thinned out (often done by hand to prevent mechanical injury).
Varieties are classified as early, mid, or late depending on the number of days from bloom to harvest; clingstones tend to begin earlier than freestone cultivars.
Pests & Diseases
Although its fuzzy exterior is said to protect peaches, a number of pests are still attracted to the succulent fruit including squash bugs and stink bugs, which bite into developing drupes, leaving tiny marks on immature fruit that can turn into wrinkles as the skin matures.
Most of these imperfections are harmless and occur frequently in organics due to restrictions on pesticide use.
Other pests of concern include aphids, beetles, borers (including the aptly named peach tree borer), caterpillars, cutworms, leaf hoppers, leafrollers, moths, nematodes, scale, and spider mites.
Peaches are susceptible many viruses and diseases including bacterial canker, brown rot, coryneum blight, crown gall, grey mold, leaf curl, mosaic, powdery mildew, root rot, rust, scab, sunburn, and wood decay.
Storage & Packaging
Peaches do not ripen on their own after harvest and should be picked when ripe (though fruit intended for processing can be less mature).
Color (no green left on the skin) and firmness (a slight give to the touch) are external indicators of ripeness. If fruit is harvested too early, it can shrivel. Most trees require multiple harvests; a gentle twist should suffice to dislodge the fruit, without undue pressure as peaches are susceptible to bruising.
Peaches can be stored for 2 to 4 weeks at 31 to 32°F with 90 to 95% relative humidity. Exposure to lower temperatures can cause chilling injury; symptoms include a water-soaked appearance, internal browning, mealy flesh, and flavor loss.
Ink or black stains on the skin can occur if fruit is damaged during harvest and exposed to common metals such iron or aluminum.
References: Oregon State Univeristy, PennState Extension, UC Davis Postharvest Technology Center, University of California Agriculture & Natural Resources, University of Georgia, USDA.
GRADES & GOOD ARRIVAL
Peaches are divided into U.S. Fancy, U.S. Extra No. 1, U.S. No. 1, and U.S. No. 2 grades. All grades stipulate fruit be of one variety, mature, and well-formed (with the exception of U.S. No. 2, which are described as ‘not badly misshapen’).
Generally speaking, the percentage of defects shown on a timely government inspection certificate should not exceed the percentage of allowable defects, provided: (1) transportation conditions were normal; (2) the USDA or CFIA inspection was timely; and (3) the entire lot was inspected.
|U.S. Grade Standards||Days Since Shipment||% of Defects Allowed||Optimum Transit Temp. (°F)|
Canadian good arrival guidelines (unless otherwise noted) are broken down into five parts as follows: maximum percentage of defects, maximum percentage of permanent defects, maximum percentage for any single permanent defect, maximum percentage for any single condition defect, and maximum for decay. Canadian destination guidelines are 15-10-5-10-5.
References: DRC, PACA, USDA.