Pear tree in winter

Origin, Domestication, and Dispersing of Pear (Pyrus spp.)

Abstract

The pear (Pyrus communis L.) is a typical fruit of temperate regions, having its origin and domestication at two different points, China and Asia Minor until the Middle East. It is the fifth most widely produced fruit in the world, being produced mainly in China, Europe, and the United States. Pear belongs to rosaceous family, being a close “cousin” of the apple, but with some particularities that make this fruit special with a delicate flavor. Thus, it deserves a special attention and a meticulous review of all the history involved, and the recent research devoted to it, because of the economic and cultural importance of this fruit in a range of countries and cultures. Therefore, the purpose of this literature review is to approach the history of the origin, domestication, and dispersal of pears, as well as reporting their botany, their current scenario in the world, and their breeding and conservation.

1. Introduction

Pear, a typical fruit of temperate climates, with delicate pleasant taste and smooth, has a wide acceptance throughout the world. By its shape, it inspires designers and architects. The fruit pleases generations; already in 1661, Jean-Baptiste de La Quintinie, lawyer and botanist, responsible for the gardens of the Versailles palace, passionate about the cultivation of pears, wrote in reports: “It must be confessed that, among all fruits in this place, nature does not show anything so beautiful nor so noble as this pear. It is pear that makes the greatest honor on the tables…”

The pear is mainly consumed in natura, pies, cakes, accompanying strong cheese or carpaccio, risotto, jams, and ice creams and is a great fruit to be consumed in diets because of its low caloric value. It has high nutritional value with reasonable amounts of vitamins A, B1, B2, B3, and C and minerals like sodium, potassium, phosphorus, calcium, magnesium, and iron. It has a lot of fiber, giving excellent results in the treatment of constipation and intestine inflammation. Many recommend pears to cure anomalies such as cystitis and kidney stones .

Belonging to the genus Pyrus, which originated in the Tertiary period, in Western China, the pear had its dispersion from northern Italy, Switzerland, former Yugoslavia, Germany, Greece, Moldova, and Ukraine to the East, in countries such as Iran, Uzbekistan, China, Japan, Korea, and Bhutan. Commercially, it is divided into two major groups: European and Asian pears. The first, with elongated and full-bodied texture, and the second, with sandy texture and rounded body, make this fruit the ninth in world production, being mainly a commodity in China .

2. Taxonomy, Origin, and Speciation

The name pear is derived from Latin, pera or pira, with some variants like in French as poire, in German as peer, and in Greece as acras as wild type and apios as cultivated pear.

It belongs to Equisetopsida C. Agardh class of vascular plants, Magnoliidae Novák ex Takht subclass, characterized by plants that have ribbed leaves and flowers. Belonging to the Rosales Bercht. & J.Presl order, and Rosaceae Juss family, with hermaphrodite flowers, polypetalae and perigynics stamens, the pear, of Pyrus L., gender is a fruit of big importance for the agriculture of latitude moderate countries, being cultivated on a large scale in China, Western Europe, and the United States .

The Maloideae subfamily, where the Pyrus gender belongs, has a basic chromosome number as , which is fair if compared with other species of Rosaceae, where or . Of the three hypotheses that emerged from the 1920s to explain the event, the most accepted theory suggests an allotetraploid or allopolyploid from the cross between two primitive forms of Rosaceae family, Prunoideae with and Spiraeoideae with . This theory was based on the observation of a predominance of univalent (unpaired chromosomes) and not from multivalent chromosomes during meiosis. Subsequently, isozyme studies supported this theory . Most cultivated pears are diploid (), but there are a few polyploid cultivars of P. communis and Pyrus × bretschneideri. According to some authors , the speciation of Pyrus occurred without a change in chromosome number. It is believed that gender Pyrus originated during the Tertiary period (65 to 55 million years ago) in the mountainous regions of western China where a very large number of species of the gender Pomoideae and Prunoideae are concentrated. Taking into consideration the areas of distribution of the various genres of Pomoideae, it is likely that the common ancestor of these was widely distributed in that territory during the Cretaceous or Paleocene and prior to the Tertiary. Evidence suggests that pear dispersion and speciation followed the mountain ranges to both the east and the west . In this period, only few traces of leaves in some localities from eastern Europe and the Caucasus were found, as the village of Parschlug, Austria, and the Kakhetia mountains, where Pyrus theobroma fossils were found. Whereas in eastern Georgia, Horizon Akchagyl, Azerbaijan, and Turkey, Pyrus communis L. fossil leaves were also found. In postglacial records, traces of fruits were found in lacustrine deposits in Switzerland and Italy . It is believed that the process of domestication followed what is currently seen in the Caucasus, where one can find many types of pear trees that grow abundantly .

There are two domestication centers and primary origin of the genus Pyrus: the first is located in China, the second located in Asia Minor to the Middle East, in the Caucasus mountains, and a third secondary center located in Central Asia .

The number of cataloged species varies greatly according to the interpretation of each author, 20 to 75 species . There are 23 wild species cataloged, all native to Europe, temperate Asia, and northern mountainous regions of Africa . Pears are classified into three groups according to the number of carpels and fruit size: small fruits that have two carpels known as Asian pears, large fruits with five carpels, and fruits with three to four carpels that are hybrids of fruits mentioned above. Asian pears have a crisp texture, while the European pear has a buttery and juicy texture, with characteristic flavor and aroma. Pears are propagated by grafting, where the graft is adapted against stresses such as soil alkalinity, drought, cold. Species diversity is concentrated in western Eurasia to eastern Asia and especially in China (Table 1), but several species are mentioned by many authors, without a consensus, which hampers an organization, as many are hybrids between species, and in some cases, different regions use different names for the same cultivars . In these two regions, two distinct groups of species, eastern and western, are formed (Table 2). Studies indicate that there is a large genetic distance between these two groups . The first is focusing on most cultivated pears, found in Europe, North Africa, Asia Minor, Iran, part of Soviet Central Asia, and Afghanistan. The second group includes species that are concentrated in East Asia, the Tien-Shan and Hindu Kush mountains, and Japan. In the latter, there is a very large group of cultivars in China and Japan . Currently there are several works that aim to estimate the genetic distance among the different cultivars, concentrated in gene banks and breeding programs.

Species Site of origin Crop
Pyrus  alnifolia  (S.  and  Z.)  Franch.  and  Sav. Russian Far East, China, Japan, Korea, Taiwan *
Pyrus  armeniacifolia  T.  T.  Yu China *
P.  aucuparia  var.  randaiensis  Hayata Taiwan *
Pyrus  baccata  L. Russia, Mongolia, China, Korea *
Pyrus  baccata  var.  aurantiaca  Regel Russia, Mongolia, China, Korea *
Pyrus  baccata  var.  himalaica  Maxim. China, Bhutan, India, Nepal *
Pyrus  baccata  var.  mandshurica  Maxim. Russia, China, Japan, Korea *
Pyrus  betulifolia  Bunge China, Laos *
Pyrus  ×  bretschneideri  Rehder China *
Pyrus  calleryana  Decne. China, Korea, Taiwan, Vietnam USA, Canada
Pyrus  calleryana  var.  dimorphophylla  (Makino)  Koidz.   Japan *
Pyrus  calleryana  var.  fauriei  (C.  K.  Schneid.)  Rehder   Korea *
Pyrus  calleryana  var.  koehnei  (C.  K.  Schneid.)  T.  T.  Yu   China *
Pyrus  cathayensis  Hemsl.   China *
Pyrus  delavayi  Franch.   China *
Pyrus  discolor  Maxim. China *
Pyrus  doumeri  Bois China, Taiwan, Laos, Vietnam *
Pyrus  folgner  (C.  K.  Schneid.)  Bean China *
Pyrus  foliolosa  Wall. Burma, Bhutan, India, Nepal, China *
Pyrus  glabra  Boiss. Iran *
Pyrus  gracilis  Siebold  and  Zucc.   Japan *
Pyrus  harrowiana  Balf.  f.  and  W.  W.  Sm.   China, India, Nepal, Burma *
Pyrus  heterophylla  Regel  and  Schmalh. Kyrgyzstan, Tajikistan, China *
Pyrus  hondoensis  Nakai  and  Kikuchi Japan *
Pyrus  ×  hopeiensis  T.  T.  Yu China *
Pyrus  hupehensis  Pamp. China, Taiwan *
Pyrus  indica  Wall. South Asia and Far East Asia *
Pyrus  japonica  Thunb. Japan *
Pyrus  keissleri  (C.  K.  Schneid.)  H.  Lev.   China, Myanmar *
Pyrus  kansuensis  Batalin China *
Pyrus  lanata  D.  Don Afghanistan, India, Nepal, Pakistan *
Pyrus  matsumurana  Makino Japan *
Pyrus  nussia  Buch.-Ham.  ex  D.  Don Far East, South Asia *
Pyrus  ×  phaeocarpa  Rehder China *
Pyrus  pohuashanensis  Hance Russia, China, Korea *
Pyrus  prattii  Hemsl. China *
Pyrus  prunifolia  Willd. China *
Pyrus  pseudopashia  T.  T.  Yu China *
Pyrus  pyrifolia  var.  pyrifolia China, Laos, Vietnam *
Pyrus  ringo  Wenz.   China, Korea *
Pyrus  ringo  var.  kaido  Wenz China *
Pyrus  scabrifolia  Franch.   China *
Pyrus  scalaris  (Koehne)  Bean China *
Pyrus  ×  serrulata  Rehder China *
Pyrus  sieboldii  Regel   China, Japan *
Pyrus  sikkimensis  Hook.  f.   China, Bhutan, India *
Pyrus  sinensis  var.  maximowicziana  H.  Lev. Korea *
Pyrus  ×  sinkiangensis  T.  T.  Yu China *
Pyrus  spectabilis  Aiton   China *
Pyrus  taiwanensis  Iketani  and  H.  Ohashi Taiwan *
Pyrus  ussuriensis  Maxim. Russia, China, Japan, Korea, Brazil Brazil
Pyrus  ×  uyematsuana  Makino Japan, Korea *
Pyrus  vestita  Wall.  ex  G.  Don China, Bhutan, India, Nepal, Myanmar *
Pyrus  vilmorinii  (C.  K.  Schneid.)  Asch.  and  Graebn. China *
Pyrus  xerophila  T.  T.  Yu China *
Pyrus  yunnanensis  Franch. China, Myanmar *
Pyrus  zahlbruckneri  (C.  K.  Schneid.)  Cardot   China *
Pyrus  tschonoskii  Maxim. Japan *
Pyrus  cydonia  L. Iran, Armenia, Azerbaijan, Russia, Turkmenistan *
Pyrus  germanica  (L.)  Hook.  f. Middle East and Northern Asia *
Pyrus  korshinskyi  Litv. Afghanistan, Tajikistan, Uzbekistan *
Pyrus  kumaoni  Decne. Middle East, Far East and South Asia *
Pyrus  salicifolia  Pall. Iran, Armenia, Turkey, Arzebaijão *
Pyrus  trilobata  (Poir.)  DC.   Israel, Lebanon, Turkey, Bulgaria, Greece *
Pyrus  turkestanica  Franch. Kyrgyzstan, Tajikistan, Turkmenistan, Afghanistan *
The same origin.
Source: USDA (2012) .

Table 1 Pyrus species and hybrids from Asia.

Species Geographic distribution-site of origin Crop
Pyrus  aria  (L.)  Ehrh. Canary Islands, North Africa, All of Europe *
Pyrus  aria  (L.)  Ehrh.  var.  cretica  Lindl. North Africa, Middle East, Central Europe Oriental and Southern and Turkmenistan *
Pyrus  aucuparia  var.  dulcis  (K.)  A.  and  G. All Europe North America
Pyrus  boissieriana  Buhse Azerbaijan, Turkmenistan, Iran *
Pyrus  korshinskyi  Litv.  subsp.  bucharica  (Litv.)  B.  K. Former Soviet Union *
Pyrus  bulgarica  Kuth.  and  Sachokia  (Pyrus  ×  nivalis  Jacq.) Western Europe, Central Eastern and Southern *
Pyrus  caucasica  Fed.   Eastern Europe and Central Greece *
Pyrus  chamaemespilus  (L.)  Ehrh. Western Europe, Central Eastern and Southern *
Pyrus  communis  L. All Europe Eastern Europe Central, South and West, and South America
P.  communis  var.  cordata  (Desv.)  H.f.   UK, Portugal, Spain, France *
P.  communis  subsp  gharbiana  (T.)  Maire   Algeria, Morocco *
P.  communis  subsp.  marmorensis  (Trab.)  Maire   Morocco *
P.  communis  subsp.  pyraster  (L.)  Ehrh. Western Europe, Central Eastern, and Southern *
Pyrus  ×  complexa  Rubtzov Former Soviet Union *
Pyrus  cossonii  Rehder Algeria *
Pyrus  crataegifolia  Savi   Turkey, Albania, Serbia, Greece, Italy, Macedonia *
Pyrus  cuneifolia  Guss. Central Eastern Europe, South and Central *
Pyrus  decipiens  Bechst. All Europe and North Africa *
Pyrus  domestica  (L.)  Sm. Algeria, Cyprus, Eastern Europe Central West and Meridional *
Pyrus  elaeagrifolia  Pall. Turkey, Ukraine, Albania, Bulgaria, Greece, Romania *
Pyrus  elaeagrifolia  subsp.  kotschyana Turkey *
Pyrus  germanica  (L.)  Hook.  f. Middle East, Eastern Europe, Central, Southern and Northern Asia *
Pyrus  gharbiana  Trab. Algeria, Morocco *
Pyrus  intermedia  Ehrh. All Europe *
Pyrus  malus  subsp.  paradisiaca  (L.)  Schubl.  and  G.  Martens Western, Eastern, and Central Europe and Greece *
Pyrus  minima  Ley   UK *
Pyrus  nebrodensis  Guss. Italy – Sicily *
Pyrus  pinnatifida  Ehrh. All Europe *
Pyrus  praemorsa  Guss South of Italy, France *
Pyrus  sachokiana  Kuth. Georgia *
Pyrus  spinosa  Forssk. Central Eastern Europe, South, and Central *
Pyrus  sudetica  Tausch   Western Europe, Central Eastern, and Southern *
Pyrus  syriaca  Boiss. Caucasus and Middle East Region *
Pyrus  torminalis  (L.)  Ehrh. North Africa, Middle East, South Caucasus, whole Europe *
Pyrus  trilobata  (Poir.)  DC.   Turkey, Bulgaria, Greece, Israel, Lebanon *
The same origin.
Source: USDA (2012) .

Table 2 Pyrus species and hybrids originating in Europe and Southern Africa.

Researchers at the University of Lleida (UDL-ETSIA) could estimate the genetic distance of 141 Spanish accessions of P. communis (past and current) through eight SSR markers. Thirteen well-known Spanish cultivars that represent their diversity were also used, but all thirteen were grouped into a single cluster, showing the narrow genetic base of cultivars P. communis in Spain, mainly caused by market demands .

Another study was conducted by a group of Chinese researchers, in which, through six SSR markers, it was possible to verify the genetic distance of 98 species of Pyrus, including 51 Pyrifolia, Japanese and Chinese Pyrus, 11 P. ussuriensis, 24 Chinese white pears, six wild types, two Korean species, two P. communis cultivars, and 2 unidentified types. The results showed the grouping of these cultivars in 10 groups, with 4 groups composed of white and sandy pears of Chinese and Japanese origin. The results showed that Japanese cultivars have as parents, Chinese sandy pear. Western cultivars formed separated and distant groups from the eastern pears .

Many studies have been conducted in the context to identify genetic variations and clustering of populations of cultivated pear in China, since the fruit is a commodity of great importance to this country, as a study of 233 landraces of P. pyrifolia, the “sandy pear,” was able to determine the level of genetic diversity and relatedness of companies by 14 SSR markers .

In 2013, the pear genome sequencing was completed by combining the illumina sequencing technology and a BAC by BAC (bacterial artificial chromosome) strategy in an Asian pear named “Suli” . This strategy minimized the limitation of the sequencing of a heterozygous genome. The results showed a frequency of 1.02% of SNPs and 53.1% of repeated sequences in the pear genome. It was verified that the genomic portion of pear and apple is very similar, and the major differences between them are the repeated sequences that are actively transposing.

The pear genome sequencing project concluded that the average density of genes is one per 12 kb in at least 42,812 gene loci, a similar number comparing to other plants, and that the pear and apple genome are almost equal in gene numbers. The project also showed that the lignin content found in pear is similar to that of poplar, indicating that this lignin content is involved in the stone cell formation . From the genomic approaches used in this project, a better understanding of this fruit crop has been achieved, which will reflect on future improvements.

3. Domestication and Breeding

Domestication has as a consequence the change in gene frequencies regarding to the original populations. A fully domesticated species is dependent upon man for its survival; in other words, it cannot reproduce in nature itself. The domestication of fruits began only around 6,000 years ago, through vegetative propagation, due to high rate of heterozygosity in them. As a consequence, self-fertility in pear and peach trees, hermaphroditism in grape, parthenocarpy, seedless fruits on banana, and absence of spines in some fruits emerged. During this period, ancient Mediterranean fruits such as grape, olive, fig, and pomegranate have been domesticated. Even citrus, banana, apple, pear, quince, medlar, almond, apricot, cherry, peach, and plum were domesticated in Central and East Asia. Some fruits such as kiwi, blueberry, and pecan were domesticated only in the 19th and 20th centuries. The earliest mention of growing pears in Europe was made by Homer in ancient Greece, a little less than three thousand years ago, who wrote that “Pears are a gift of God” . It was then that breeding started and also the history of the pear as a cultivated plant. Theophrastus (371–287 BC), another Greek, also made important reports on pear. The same distinguished the wild forms from cultivated ones and suggested that bred genotypes received a special name and other important observations on breeding in general . A large contribution to pear cultivation was made by the Romans. Portius-Cato (235–150 BC) described the methods of propagation, grafting, and caring for fruit and also described six cultivars of pear. Another great writer of ancient Rome, Terentius Varro, dedicated some of his work to agriculture (116–27 BC), describing grafting methods and storage. Among the Roman historians, the most important of all was Pliny the Elder (23–79 AD), who described in detail almost all varieties of the season, in a manuscript with more than sixty editions. In summary, the ancient Romans reported more than 40 cultivars existing in the 1st century BC and described methods of cultivation similar to the practiced currently . Little is known about introducing pear in France, but in the mid-800, the cultivation has developed very well on site, making the country in the sixteen and seventeen centuries the world’s largest producer of the fruit. During the eighteenth century, Belgium developed numerous cultivars, including some that are important even today, as the varieties “Beurre Bosc,” “Beurre d’Anjou,” “Flemish Beauty,” and “Winter Nelis” .

The pear improvement happened in Europe from two species: Pyrus communis and P. nivalis. The first, European Common pear, is completely barren and has in its gene pool an influence of other species such as P. eleagrifolia, P. spinosa, P. nivalis, and P. syriaca . The second, used to make wine, has been of great importance in Britain and France for over 400 years. Most cultivars released in Europe were developed via open pollination and fruits were selected according to their softness and buttery aspect.

In Asia, the cultivation began over 2500 years ago, with the main species Pyrus pyrifolia, Pyrus serotina, and Pyrus ussuriensis. The result was reported in written Chinese (Shi Jing) and other books for at least 1500 years . In Japan, pear seeds dating from the years 200–300 were found. During the Edo period in Japan (1603–1868) over 150 cultivars were documented; this time the pears were planted in the corners, like a talisman to avoid the “evil eye.”

One of the main characteristics of Asian pears is the crispy, sweet, and juicy acid pulp. The pulp is characterized by having “stone cells” which are sclerenchyma cells that differ from fiber because they are very elongated. They also offer a sandy texture to the fruit . The sizes vary from rounded as apples, these being the most cultivated, until pears to the top and bottom elongated bulbous pears, similar to the European pears. The fruits are very sensitive to physical damage, both at harvest and in the classification as storage and marketing.

Pear was introduced by the English and French settlers in the United States and Canada, and in 1629, there was record of its cultivation in New England . Unlike Europe, which grew via grafting pears, pear in the United States was initially cultivated by seeds, which resulted in a much higher genetic variability than in Europe , resulting in a number of different varieties in America. Currently, many European pears are well established in North America; however, the U.S. genotypes cannot adapt to the climate and European soil (Table 3). In the United States, in the latter half of the nineteenth century, breeders have used the pear wild type (crosses between Asian and European pears) to their crosses, in order to obtain greater resistance to cold and “fire blight” disease caused by the bacterium Erwinia amylovora that is widely spread, though causing a large reduction in the quality of the fruit, which was repaired with successive backcrosses. The most notable difference between these junctions is undoubtedly the texture . Wild type pears are used today as a rootstock because of their cold tolerance and adaptability to different environments .

Table 3 Pyrus species and hybrids originating in the Americas.

4. Production and Economic Importance

A medium-sized fruit has about 58 calories, 6 grams of fiber, and 7.0 mg of vitamin C, besides being free of fat and sodium and possessing significant amounts of calcium, iron, magnesium, phosphorus, potassium, zinc, copper, manganese, and phytosterols . Pears, because they are part of the family Rosaceae, have sorbitol as their main translocated sugar that is converted into glucose, fructose, and sucrose. The sugar content varies greatly among Japanese, Chinese, and European pears . Japanese and Chinese pears are those with higher and lower sucrose content, respectively, and the European pears are those with a high content of fructose.

Pear is used mostly for fresh consumption or for the production of jams , being the ninth most important cultivated fruit in the world (Table 4). China is the world’s largest producer (Asian pear) and the United States is the second largest producer, being the first producer of European pear type. Together, the top ten producers occupy an area of 1.360.230 HA annually (Table 5).

Table 4 World production of fruit crops in the years 2010 and 2012 in tonnes. Table 5 World production of pear in 2012 (tonnes) and the area (ha) harvested in the ten most productive countries.

The European pear (P. communis) is grown into five major regions: Europe, North America, South America, South Africa, and Oceania, while production of Asian pear (P. pyrifolia) is concentrated in Asia.

China’s pear production has increased steadily during the 1980s and early 1990s because of the expensive planting. This rate of growth generated an amount of 7.74 million metric tons of fresh pear in that time. Data show that China produces more than twice the total world production, making the crop a commodity of great importance to this country .

5. Conclusion

Documentation of botanists and biologists over the last hundred years was of great importance to collect the available data in this review.

Undoubtedly, a fruit that produces around 24 billion tonnes per year is considered a great success in the world market. This success is mainly due to the wide commercial acceptance around the world, its nutritional importance, and its adaptability in places with large planting conditions and marketing.

The recent advances achieved in the last year with the pear sequencing genome project will provide new opportunities for developing improved genotypes tolerant to biotic and abiotic stresses and also high quality fruits regarding nutritional and sugar content.

The understanding of the history of pear for agriculture is of paramount importance, since scientists and students could have a better grasp of the richness of this fruit crop and its trajectory associated to humankind.

Conflict of Interests

The authors declare that there is no conflict of interests regarding the publication of this paper.

History

Called “a gift of the gods” by the Greek poet Homer, pears have been praised since ancient times. The early Romans developed over 50 pear varieties and spread them far and wide throughout Europe. Since then, hundreds more varieties have been introduced, the most popular being the Bartlett.

The Bartlett pear got its start in 17th Century England, originally known as the Williams pear before crossing the Atlantic with the early American colonists. Nurseryman Enoch Bartlett of Massachusetts, unaware of the pear’s true name, began distributing the variety under his own name in 1812 and it quickly became America’s favorite. By 1849, Bartlett pear trees had arrived in California, brought West by prospectors eager to strike it rich in the Gold Rush. Those who planted and farmed pears found their true fortunes in this golden fruit. With its Ideal climate and soils, California grew to be the nation’s supplier of pears as the first large-scale commercial fruit industry emerged. Many of the farming families who originally planted pears near Sacramento’s Gold Rush communities are still growing pears today. They farm on the same land that was planted with Bartlett pears generations ago.

Asian Pears Availability:
  • spring
  • fall
  • winter

These pears ripen a little on the early side, often by late August, early September. Unfortunately, they don’t stick around too long, usually only available until the first month or two of spring.

ABOUT ASIAN PEARS

Fairly new to the United States, there are over 1000 varieties of Asian pears, also known as “Apple Pears”, originally from Japan. But don’t let the name “Apple Pear” confuse you. Even though the Asian pear looks like a cross between an apple and a pear, the resemblance is only skin deep. There are also several other differences between Asian pears and the more common European pear. Asian pears reach optimum quality when allowed to ripen on the tree, similar to apples and peaches and are more crisp and tart then other pears. European pears are usually harvested in a green stage and allowed to ripen at room temperature and have a sweeter, more mellow taste.

ASIAN PEAR TASTE & RIPENESS

The Fruit is yellow-green to pale yellow and smooth with small lenticels. This large white-fleshed pear is sweet, firm, crisp, juicy and aromatic. Being one of the rare pears that ripens on the tree, our delicious Imperial Asian pears arrive at your door ready to eat.

Pears

Introduction

Commercial pear production is concentrated in the Northwest United States. Total U.S. production in 2014 was more than 1.6 billion pounds, down five percent from 2013 and was valued at $457.1 million – up six percent from the previous two years (NASS, 2015).

There are two types of pears: The European or French pears (Pyrus communis) including varieties such as, Bartlett, Bosc and D’Anjou, and Asian pears (Pyrus pyrifolia) with varieties such as, Hosui and Nijisseiki. Asian pears are also known as “apple-pears” because of their apple-like texture (University of Kentucky – Cooperative Extension, 2014)(Pennsylvania State University – Extension, 2015
U.S. per capita consumption of fresh pears was 3.22.8 pounds in 201309. Per capita consumption of all pear products was about 6.27 pounds in 201310 (ERS, 2014).

Marketing Channels

The marketing season for pears differs among the states they’re produced in and their varieties. For California, Oregon and Washington, the marketing season for Bartlett pears is from July to December. For other pears it is from July to June. In all other states the marketing season is from August to November (NASS, 2015).

Pear has a very sweet flavor, but is not overbearing, making it a great fruit to incorporate into processed foods such as, canned pears, baby food, glazes, vinaigrettes, and fruit bars. A way to add value to fresh pears could be starting a U-pick operation. Many consumers are concerned about where their produce comes from; therefore U-pick operations have the ability to make consumers feel more secure and connected to their food. Some very important factors to consider regarding U-pick operations are making sure the site is convenient and appealing to customers. Often U-pick operations will supply a farm stand with already picked product for people who do not have the time, ability or want to pick their own product (University of Tennessee – Extension, 2014).

Tapping into niche markets is another way value can be added to a product. In recent years apple ciders and alcoholic pear beverages (known as perry), have become more popular (Michigan State University – Extension, 2013).

Production

There are six main states in the U.S. that produce pears: California, Michigan, New York, Oregon, Pennsylvania and Washington. Of these states, California, Oregon and Washington make up the majority of production.

In 2014, Washington led the United States in pear production with 832 million pounds valued at $233.8 million. Oregon produced 432 million pounds valued at $127.4 million, and California
Produced 378 million pounds valued at $88.6 million. From these three states 776 million pounds were Bartlett pears valued at $180.7 million (NASS, 2015).

Exports/Imports

During the 2013/ 2014 market year, the United States exported 449 million pounds of fresh pears valued at nearly $223.7 million, and exported 13.7 million pounds of prepared/preserved pears valued at $7.4 million. The largest market for fresh pears was Mexico, followed by Canada and Russia. The largest market for prepared/preserved pears was Canada followed by Mexico and the United Arab Emirates (ERS, 2015).

The United States imported 180.7 million pounds of fresh pears in the 2013/2014 market year, valued at more than $188.9 million. The top three countries for fresh imported pears are Argentina, South Korea, and Chile (ERS, 2015).

Management

Pear trees are highly susceptible to a bacterial disease called Fire blight, caused by the bacterium Erwinia amylovora. There are some slightly tolerant varieties available. Fire blight is most likely to occur when temperatures of 75° to 85°F are followed by sporadic rain, however, proper management can lessen the disease from occurring. The tissue of fast growing trees is very sensitive, and thus activities such as heavy fertilization and excessive pruning should be avoided due to it promoting quicker growth. Irrigation during flower bloom should also be avoided, and monitoring and removal of fire blight infected areas should be done with diligence (UC IPM, 2011).

Financial

Helpful enterprise budgets for pears:

Sources

A Farmers Guide to a Pick Your Own Operation, University of Tennessee – Extension, 2014.

Asian and European Pears, University of Kentucky – Cooperative Extension, 2014.

Asian or Oriental Pears, Pennsylvania State University – Extension, 2015.

Fire Blight, University of California – Integrated Pest Management (UC-IPM), 2014.

Fruit and Tree Nut Data – Exports/Imports, Economic Research Service (ERS), USDA, 2015.
Hard cider and perry industry growing across the United States, Michigan State University – Extension, 2013
Noncitrus Fruits & Nuts, National Agricultural Statistics Service (NASS), USDA, 2015. pg. 78

Additional Links

Marketing and Production
  • European and Asian Pears, University of California-Davis – This site links to other pear sites.
  • Fresh Fruit (Apples, Grapes, and Pears): World Markets and Trade, Foreign Agricultural Service (FAS), USDA.
  • Organic Pear Production, Appropriate Technology Transfer for Rural Areas (ATTRA), NCAT, 2003 -– This for-purchase
  • Pear Bureau Northwest – This nonprofit marketing organization was established in 1931 to promote fresh pears grown in Oregon and Washington. Pears are distributed under the USA Pears logo.
Businesses/Case Studies
  • Gorge Delights – Adding Value to Pears, Ag Marketing Resource Center, 2004 – Profile of a company that processes fruit into fresh-cut slices and is making pear nutrition bars.
  • Kiyokawa Family Orchards, Parkdale, Oregon – A family-owned and operated farm that has been growing produce since 1911. Currently the farm grows mainly apples and pears with over 80 different varieties. They have a U-pick orchard with an online ripeness calendar so you know exactly when to arrive for your favorite fruit.
  • Stemilt Growers, LLC, Wenatchee, Washington – The Mathison family owns and operates Stemilt Growers and has been farming fruit since the early 1900s. They grow, pack, ship, and market fresh apples, pears, cherries, peaches, nectarines and apricots to stores worldwide.

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Links checked June 2018.

Don’t be fooled, just because temperatures drop during the winter months does not mean you can’t find fresh fruits and veggies. Among those that are in season, you will find NW-grown pears. In fact, the USDA annually recognizes December as National Pear Month. Whether you’re looking for Bosc, Anjou, Comice or anything in between, your local supermarket should have a wide variety in stock.

Pear harvest in Washington and Oregon begins in August with Bartletts and continues through September and October with winter varieties. Pears are harvested when the fruit is fully mature, but not yet ripe. This keeps the fruit’s flavor at a peak.

Pickers carefully harvest every pear by hand, and place them into special orchard bins to prevent bruising. Once filled, the orchard bins are delivered to the packing houses and immediately cooled. After they have reached the proper reduced core temperature, they are hand-packed into 40 pound boxes to be delivered to stores world-wide.

Today, the U.S. is the third largest pear producing country in the world.

Selecting/Ripening/Storing:

Pears are a unique fruit that ripen best off the tree. Because they are harvested when they are mature but unripe, you will likely find firm fruit at your local supermarket. In order to allow them to ripen, leave them at room temperature (kitchen counter or dining room table). If you need them immediately, placing them in a paper bag will help to ripen faster. Be sure to check them daily so they don’t get overripe Bartlett pears change from green to yellow as they ripen. Non-Bartlett pears (Anjou, Bosc, Comice, Concorde, Seckel and Forelle) do not dramatically change color as they ripen. The Check the Neck™ test is the best method for checking for ripeness. To do this, gently press near the stem with your thumb. When it gives to gentle pressure it is ripe, juicy, and ready to eat.

Once they are ripened, pears will generally keep in the refrigerator for 3 to 5 days. Unripe fruit can generally be kept for a week or more, however, pears will not ripen properly inside the fridge.

USA Pear Crop Statistics

  • There are currently more than 1,600 pear growers in Oregon and Washington
  • Pears are Oregon’s number one tree fruit crop, its #9 agricultural commodity, and Oregon’s Official State Fruit
  • Oregon’s total pear production ranks 3rd overall in the United States and 2nd in terms of fresh pear production
  • Washington’s fresh pear production is the largest in the United States
  • In Washington State, pears are the third most valuable tree fruit crop behind apples and sweet cherries, and the tenth most valuable agricultural commodity overall
  • Combined annual fresh pear (not canned) harvest for Washington and Oregon currently averages over 582,000 tons
  • Washington and Oregon export about 35% of their fresh pear crop to more than 50 countries around the world.
  • About a quarter of the overall pear crop is canned (not represented by USA Pears/Pear Bureau Northwest). Most canning pears are Bartletts, with 63% of this variety being used for canning and processing into juices, etc.

For more information on Northwest Pears, visit usapears.org.

Winter Pear Varieties: Growing Winter Pears In The Garden

There are two seasons of pear varieties: summer and winter. Winter pear varieties require cold storage before they can start ripening while summer pears do not. One reason for growing winter pears is their long life of storage. Unlike summer/fall pears, which ripen after being harvested, winter pears need cold storage for at least 3 weeks before bringing them out and letting them ripen. According to winter pear information, without this step, the fruits will not mature properly.

What is a Winter Pear?

Sweet juicy pears are one of the few fruits that do not ripen on the tree. Because they ripen from the inside out, by the time they reach perfect readiness on the tree, as judged by the eye, the centers would be mushy. For this reason, winter pears are picked when hard and green, stored in a cool location and then placed in a warmer place to finish ripening. Winter pears are so named because of when they are marketed, although they are ready for harvest a month or more after other varieties.

Pears are members of the rose family and probably originate from Eurasia. Winter pears are ready for harvesting in fall. They are then stored in refrigerators for 3 to 4 weeks at 32 to 40 degrees Fahrenheit (0 to 4 C.) to allow the fruit to convert starches to sugars.

The variety was a favorite with aristocratic French who developed several of the most popular kinds of winter pear. Bosc, Anjou and Comice are all French varieties still grown today. Add in the following and you have the most popular winter pear varieties commercially grown:

  • Forelle
  • Concord
  • Seckel
  • Orcas
  • Rescue
  • Flemish Beauty
  • Conference
  • Duchess
  • Dana’s Hovey

Growing Winter Pears

Pear trees are grafted onto rootstock that conveys certain traits such as disease resistance, cold tolerance and even size. Pear trees prefer temperate regions in full sun with average, well-draining soil.

Trees will benefit from judicious pruning in late winter to spring for the first few years to develop a healthy vase-like shape and strong scaffold branches to hold heavy yields. Young trees should be trained to a thick stake initially to keep the central leader straight and true.

Fertilize trees in early spring and prune out dead or diseased wood as needed. Growing winter pears is not for the impatient. It can take 20 years or more from planting for your first crops but, boy, is it worth it.

Pruning & Training Apple & Pear Trees

Training and pruning are essential for growing fruit successfully. Fruit size, quality and pest management are influenced by training and pruning. Untrained and unpruned trees become entangled masses of shoots and branches that produce little or no fruit and harbor insects and diseases.

Consider the following tips when training and pruning fruit crops:

  1. Before training or pruning a plant, visualize the results of the action. Once a branch is pruned out or removed, it cannot be replaced.
  2. Train as much as possible and remove as little as possible. Bending and tying shoots instead of cutting them out, especially on apple and pear trees can induce early fruit production.
  3. Use sharp pruning tools to make clean cuts.
  4. Discard or compost pruned out shoots and branches. These plant parts will serve as dwelling sites for insects and diseases and should be removed from the area to reduce pest populations.

Training begins at planting and may be required for several years. Pruning is an annual management practice. Two basic pruning cuts are heading and thinning. Heading or heading back removes the terminal portion of shoots or limbs. Thinning removes an entire shoot or limb to its point of origin on the main branch or lateral. Light pruning can be performed throughout the growing season to remove broken, injured or diseased branches and to improve air circulation to control foliar diseases. Major removal of twigs and branches should be done during the dormant season, preferably before active growth begins in the spring. Training and pruning procedures vary according to the type, age and variety of fruit crop. The types of branching involved in pruning are illustrated below.

Suggested Pruning Cuts

A. Suckers.
B. Stubs or broken branches.
C. Downward-growng branches
D. Rubbing or criss-crossing branches
E. Shaded interior branches
F. Competing leaders
G. Narrow crotches
H. Whorls

Initial Training & Pruning

The day apple trees are planted is the day to begin to train and prune for future production. Too often backyard growers plant apple trees and leave them untended for several years. This neglect results in poor growth and delayed fruiting.

Apple trees are trained to a modified leader system. The tree should be trained with one central leader or main trunk in the center, with several wide-angled limbs spaced around the leader. The tree should mature to a pyramidal shape.

The picture below shows correct and incorrect pruning of an apple tree.

Use “spur-type” strains or grow apples on dwarfing rootstock to make training and pruning easier. Spur-type and dwarf trees produce fruit at an earlier age than full-sized trees. These trees are also easier to manage and harvest than full-sized trees are.

If one-year-old unbranched “whips” are planted, head to the desired height – about 28 to 32 inches for standard and 30 to 35 inches for spur-type and semi-dwarf trees.

When the buds grow out to 4 to 5 inches, select a central leader and scaffold branches. Scaffolds (side branches) should be spaced at least 6 inches apart vertically and at equal intervals around the trunk. Between three and six branches may be selected as scaffolds during the first summer or may be left to grow throughout the season and selectively pruned out during the dormant season.

If young trees are branched when they come from the nursery or garden center, remove any broken branches and those that form angles less than 45° with the main trunk. Eliminate competing leaders by removing the less desirable branch. Head-back the central leader by one-third in the second year. Make the cut close to a bud that is growing in a suitable direction or to a lateral branch. Keep pruning to a minimum during the early years to encourage the trees to produce fruiting wood.

Pear trees naturally develop narrow angled, upright branches. To train properly angled scaffold branches, either weight the branches, tie branches to pegs in the ground or brace the branches apart with spacer sticks.

Pruning Bearing Trees

Prune bearing trees to maintain a balance between vegetative growth and fruit production. The first three years should be spent on training only, but by the fourth and fifth years, the trees can be allowed to produce a light crop.

Pruning bearing trees is critical to maintain healthy fruiting wood. Remove weak, “shaded-out” wood, diseased or dead wood, watersprouts and root suckers. Control tree height by cutting back the top portion of the tree to weak lateral branches.

For flower buds to develop well, all branches of the tree should be exposed to adequate sunlight. This can be a challenge in the lower portion of the tree. On the lowest whorl of secondary scaffolds, merely tip the terminal shoots of these branches rather than cutting them back to laterals. If the fruit quality and yield diminish in older trees, some heavy pruning may be done carefully to restore tree shape and allow more sunlight to penetrate into the tree.

Summer Pruning

Summer pruning is advised, especially for removing waterspouts, rootsuckers and fire-blight-infected wood. Summer pruning can also be used during the first three years of tree training to produce the desired tree shape. Undesired growth should be removed in early summer or after harvest between late August and early September. Also, note that pruning should be focused on thinning out rather than heading-back

Heading-back cuts may stimulate new growth near the cut. If the trees are heavily pruned, reduce the amount of fertilizer applied in relation to the severity of pruning. Heavily pruned trees may not need fertilizer for a year or two.

Thinning

Apple and pear trees grown under favorable conditions will set more fruit than they are capable of carrying to maturity. It is essential to remove excess fruit from the trees to assure satisfactory development of fruit remaining on the tree. Failure to remove the excess fruit will decrease flower formation for the following year and cause the tree to produce a crop only every other year.

Fruit should be removed by hand to one per cluster. Space fruiting clusters about every 6 inches along the limb. To remove the fruit without damaging the spur or other pears on the spur, hold the stem between the thumb and forefinger and push the fruit from the stem with the other fingers. This method will remove the pear leaving the stem attached to the spur.

The earlier that hand thinning is completed, the more effective it will be in achieving the desired results. Midsummer thinning will help to improve fruit size, but it will not aid in the formation of next year’s flower buds. Most of the flower buds for next year are initiated during a four to six week period following full bloom, so thin before this time.

Pruning Neglected Apple Trees

Many people will purchase a house where an apple tree was planted on the property several years ago. Often, the previous owners did not take the time to properly prune the tree. The tree has become bushy and weak and will produce very poor quality apples. Such a tree requires extensive corrective pruning.

The main objective in pruning such a tree is to try and open up the interior to allow good light penetration. The first step is to remove all the upright, vigorous growing shoots at their base that are shading the interior. As with the young apple trees, it is necessary to select 3 to 5 lower scaffold branches with good crotch angles and spaced around the tree. Limbs with poor angles, and excess scaffold limbs, should be removed at their base. In some cases it is advisable to spread the corrective pruning over two to three seasons. When severe pruning is done in the winter, the trees should not be fertilized that spring.

Although pruning is definitely a human invention, and trees can go without it to develop naturally,
it presents the advantage of renewing the plant’s vigor and increasing its fruit productivity.

Jump in the water, if you follow these tips, you should quickly get familiar with this procedure, and will get better at it as years go by.

  • For all the other types of pruning, check out all the articles about pruning plants.

Pruning pome trees

Pruning seed fruit trees increases fruit formation and will let your orchard bear more and more fruit as years go by.

  • No pruning is ever a bad pruning, except if it is too drastic or if performed at the wrong time.

It will help your tree grow well.

In winter, it’s also the time to remove moss, lichen and old bark which are safe harbors for all sorts of parasites and diseases.

  • Read our page related to pruning apple and pear trees.

Here is the advice on growing apple trees and pear trees

  • Pear trees, growing and caring for them
  • Apple trees, growing and caring for them

Read also

  • Fruit-inducing pruning
  • Pruning shrubs and trees
  • Scale insects, common parasites on a fruit tree

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