Pear trees were brought by early colonists to America’s eastern settlements. Most trees thrived until blight decimated orchards in the region. Pioneers brought pear trees to the Pacific Northwest in the 1800s, where they flourished and continue to do so today. Growing regions in Oregon and Washington boast not only the warm days and cool nights perfect for pear growth but also have rich volcanic soils and ample moisture for trees and developing fruit. California is also a significant producer, with Michigan, New York, and Pennsylvania contributing to U.S. supply.
References: Agricultural Marketing Resource Center, Pear Bureau Northwest.
TYPES, VARIETIES & CUTS
Three basic types of pears are grown in the United States: European or French pears, Oriental Hybrid, and Asian (often referred to as ‘apple-pears’ due to their crunchy texture). Among the more popular European varieties are Bartlett, D’Anjou, Comice, and Bosc; a few Asian pear varieties are Chojuro, Ichiban Nashi (Nashi means pear in Japanese), Shinsui, Ya Li, and Yoinashi. It is unknown just how many pear varieties exist in the world, but it is believed to be in the thousands.
References: California Pear Advisory Board, Oklahoma State University, Purdue University, Texas A&M University.
PESTS & DISEASE
Pear psylla, similar to cicadas and aphids, attack all types of pear trees but are more dangerous for European than Asian varietals. Though very tiny, generally less than 3 millimeters in length, the insects can puncture and damage leaves, affect tree vigor, cause fruit drop, and honeydew secretions on fruit can lead to soot or mold. Worse yet, the insects are often able to develop resistance to insecticides.
Grape mealybugs are a pest of most deciduous fruit crops, including pear trees, where they may feed on calyxes, softening fruit. In older trees, the bugs are able to overwinter eggs in coarse bark, and become a problem in the spring. If found in harvested fruit, entire lots will be rejected as a preventive measure against further infestation.
Pear slugs are the larvae of sawflies, which deposit small bubble-like eggs on the underside of leaves. Larvae feed on foliage causing skeletonization as the layers are chewed away. Other pests of note include armyworms, cankerworms, cutworms, boxelder bugs, codling moths, leafrollers, mites, moths, lygus bugs, scale, stink bugs, and thrips.
Fire blight is the most serious of pear diseases, generally appearing in the spring and causing dark discolorations on blossoms, leaves, and twigs. In some cases, the entire tree dies.
Pear scab begins as circular, brownish spots on leaves and stalks, turning into velvety patches. Fungus can overwinter in leafy groundcover and infected twigs.
Blue mold rot is a disease rarely found in the orchard; it occurs in storage and appears as soft, watery spots, generally due to mechanical injury, bruising, and cuts.
Other diseases of concern include bacterial canker, black spot, blossom blast, crown and root rot, and pear decline.
References: Purdue University, Texas A&M University, University of California Agriculture & Natural Resources, Washington State University, West Virginia University.
CULTIVATION, STORAGE & PACKAGING
Fruit trees are not typically grown from seed but through vegetative propagation. Because pear trees do not root easily, they are propagated by budding or grafting onto a rootstock. After the tree grows in the nursery for a year, it is shipped to the customer.
Most cultivars require up to 1,200 chill hours (below 45°F) in winter to complete their dormant period. Fully dormant trees can survive temperatures as low as -25°F, pear blossoms, however, are extremely sensitive to frost and temperatures below 26°F.
Although trees tolerate multiple soil conditions, deep, well-drained soil is preferred, with plenty of water and humidity, though too much humidity can lead to blight and fungal growth.
With the exception of Asian pears, which can be eaten right off the tree if mature, European pears ripen best off the tree. Fruit is harvested by firmness (depending on variety) and stored in precooled rooms with temperatures ranging from 30 to 32°F with 90 to 95% relative humidity (Asian pears require slightly warmer temps, from 34 to 36°F with 90 to 95% humidity). If temperatures fall below 29°F, chilling injury can occur.
Ethylene enhances ripening for European cultivars; optimal conditions for ripening are 59 to 72°F with 90 to 95% relative humidity. Asian pears are sensitive to ethylene and should be separated from producers; fruit will also absorb odors from strong-smelling fruits or vegetables if stored or shipped together.
Standards are divided into summer and winter grades. Winter pear grades are U.S. Extra No. 1, U.S. No. 1, U.S. Combination, and U.S. No. 2. Summer pear grades are U.S. No. 1, U.S. Combination, and U.S. No. 2.
References: Texas A&M University, UC Davis Postharvest Technology Center, Virginia Cooperative Extension, Washington State University.