Editing Perry (section)

===Orchard management and harvesting===
[[File:Perry_Pear_Orchard,_Wick_Court_(geograph_2567501).jpg|thumb|right|Mature perry pear orchard at Wick Court, near [[Arlingham]]: As usual in traditional perry orchards, the trees are of extremely large size.]]

While cultivation of pears has been to some extent modernised, they remain a difficult crop to grow. Perry pear trees can live to a great age, and can be fully productive for 250 years. Pear trees, both domestic and perry varieties, grow incredibly slowly, taking up to, if not over, a decade before they bear enough fruit for harvest.<ref name=":42" /> They also grow to a considerable height and can have very large canopies; [[Holme Lacy Pear|the largest recorded]], a tree at [[Holme Lacy]], which still partly survives, covered three-quarters of an acre and yielded a crop of 5–7 tons in 1790.<ref name="tcppp">Oliver, T. ''[http://www.theolivers.org.uk/SFPP_Protocol.pdf The Three Counties & Welsh Marches Perry Presidium Protocol] {{Webarchive|url=https://web.archive.org/web/20110721235337/http://www.theolivers.org.uk/SFPP_Protocol.pdf |date=21 July 2011 }}''</ref> Given the long maturing period of pear trees, they can be difficult to manage against diseases. Their size makes it difficult to apply pesticides, which makes preventing [[fire blight]], a disease caused by the bacterium ''Erwinia amylovora'' that pears are even more susceptible to than cider apples, quite challenging.<ref name=":6" /> These difficulties, along with demand for perry pears having (until recently) taken a decline, have prompted a national collection of perry pear cultivars to be gathered, housed, and cared for at the Three Counties Agricultural Showground at Malvern in Worcestershire, to maintain genetic resources,<ref name=":12" /> which has now become the [[National Perry Pear Centre]] at Hartpury.<ref>{{Cite web|url=https://www.nationalperrypearcentre.org.uk/|title=National Perry Pear Centre - Conserving a part of our orchard heritage|website=National Perry Pear Centre|language=en-US|access-date=2018-05-14}}</ref> Similar germplasm repositories can be found at the [[National Clonal Germplasm Repository]] in Corvallis, Oregon.<ref>{{Cite web|url=https://www.ars.usda.gov/pacific-west-area/corvallis-or/national-clonal-germplasm-repository/docs/ncgr-corvallis-distribution-policies/|title=NCGR Corvallis Distribution Policies : USDA ARS|website=www.ars.usda.gov|access-date=2018-05-14}}</ref>

Also, key differences between cider and perry production exist in the harvesting and growing processes. Perry trees famously take more time to mature than cider trees. While cider trees may come to bear fruit in three to five years, traditionally managed perry trees typically take much longer, so much so that people say that one plants "pears for your heirs".<ref name=":0">{{Cite journal|last=Ripe|first=Cherry|date=2009|title=Perry|jstor=10.1525/gfc.2009.9.4.58|journal=Gastronomica|volume=9|issue=4|pages=58–61|doi=10.1525/gfc.2009.9.4.58|url=http://gcfs.ucpress.edu/content/9/4/58.full.pdf |archive-url=https://web.archive.org/web/20180721004648/http://gcfs.ucpress.edu/content/9/4/58.full.pdf |archive-date=2018-07-21 |url-status=live}}</ref>

Even when fully grown, pear trees bear less fruit than apples, which is one reason that perry is less common than cider.<ref name=":2">{{Cite web|url=http://shaponline.org/wp-content/uploads/2012/03/Robinson-Pear-talk12.pdf |archive-url=https://web.archive.org/web/20180517223459/http://shaponline.org/wp-content/uploads/2012/03/Robinson-Pear-talk12.pdf |archive-date=2018-05-17 |url-status=live|title=High Density Pears: Profitable Not Just for You and your Heirs|last=Robinson|first=Terrence|website=shaponline.org|access-date=14 May 2018}}</ref> When time to harvest comes, pears should be picked before they are ripe and then left to ripen indoors, while apples should be allowed to ripen on the tree.<ref name=":3">{{Cite web|url=http://extension.wsu.edu/benton-franklin/wp-content/uploads/sites/27/2013/12/Harvesting-Apples-and-Pears.pdf?x56665|title=Harvesting Apples and Pears|last=Hiller|first=Val|date=November 1997|website=wsu.edu|access-date=14 May 2018}}</ref> Both apples and pears suffer from [[fire blight]], which can devastate entire orchards, but pears are also susceptible to pear psylla (also known as ''[[Psylla pyri]]'').<ref name=":2" /> These insects kill the entire pear tree and are very resistant to insecticides, making them a severe problem for pear orchards.<ref name=":4">{{Cite web|url=http://jenny.tfrec.wsu.edu/opm/displaySpecies.php?pn=120|title=Pear psylla|website=jenny.tfrec.wsu.edu|access-date=2018-05-15|archive-date=2 June 2018|archive-url=https://web.archive.org/web/20180602003659/http://jenny.tfrec.wsu.edu/opm/displaySpecies.php?pn=120|url-status=dead}}</ref> Another added complication is that while apples are often harvested mechanically, pears must be harvested by hand, greatly increasing the time and cost of harvesting.<ref name=":5">{{Cite book|title=Pear Production Technology|last=Verma|first=M. K.|date=2014-01-01|isbn=9789383168095|pages=249–255}}</ref>