Frequently the http://www.ars-grin.gov/cor/catalogs/pyrcult.html has more information about a variety of pear than can be found anywhere else but it can be a trick to understand that information. Lets look at the pear commonly known as Docteur Desportes found in the ARS Grin catalog here https://npgsweb.ars-grin.gov/gringlobal/accessiondetail.aspx?accid=%20PI+541173. The description says "Listed in the 1912 catalog of Pepinieres Andre Leroy, Angers, France. Fruit medium or larger in size, oblate but somewhat turbinate in form. Skin fairly tough, smooth, straw-yellow in color, reasonably free from blemish, attractive. Flesh, fairly fine, buttery but not melting, juicy, comparitively free of grit. Similar and equal to Bosc in flavor characteristics. Keeps longer than Bosc in cold storage and has long shelf life. Tree vigorous, spreading, productive. Semi-dwarf on quince, moderately susceptible to fire blight. This variety appears promising as a commercial variety for areas in which it is adapted.- H. Hartman, Oregon Agricultural Experiment Station, 1957 "
The real meat and potatoes of the description is not that one it is the link at the bottom called “Detailed Accession Observation Page”. When you click on that you will get this information GRIN-Global which discusses the trees level of resistance to diseases and other problems and benefits
Observations for accession PI 541173
Characterization and Evaluation Data:
Descriptor Value Study/Environment Inventory ID
CYTOLOGIC Descriptors
PLOIDY LEVEL 2x - diploid PYRUS.PLOIDY.2012 CPYR 177 .004 PL
DISEASE Descriptors
PSEUDOMONAS 3 - (1 = NO DAMAGE, 9 = SEVERE DAMAGE) PYRUS.CORVALLIS.1988
RUST 1 - NO DAMAGE PYRUS.CORVALLIS.1986
INSECT Descriptors
BLISTER_MITES 7 - (1 = NO DAMAGE, 9 = SEVERE DAMAGE) PYRUS.CORVALLIS.1986
MORPHOLOGY Descriptors
BLOOM_DENSITY 2 - (1 = LOW, 9 = HIGH) PYRUS.CORVALLIS.1987
BLOOM_DENSITY 4 - (1 = LOW, 9 = HIGH) PYRUS.CORVALLIS.1987
BLOOM_DENSITY 1 - LOW PYRUS.CORVALLIS.1988
BLOOM_DENSITY 7 - (1 = LOW, 9 = HIGH) PYRUS.CORVALLIS.1988
CALYX P - PERSISTANT PYRUS.CORVALLIS.STD
CALYX_BASIN OM - OBTUSE MEDIUM PYRUS.CORVALLIS.STD
CARPEL_NUMBER 5 PYRUS.CORVALLIS.STD
CAVITY AS - ACUTE SHALLOW PYRUS.CORVALLIS.STD
CORE_BREAKDOWN 1 - NONE PYRUS.CORVALLIS.STD
DOTS O - OBSCURE PYRUS.CORVALLIS.STD
FLAVOR R - AROMATIC PYRUS.CORVALLIS.STD
FLAVOR S - SWEET PYRUS.CORVALLIS.STD
FLESH_COLOR W - WHITE PYRUS.CORVALLIS.STD
FLESH_TEXTURE 5 - (1 = FINE, 9 = COARSE) PYRUS.CORVALLIS.STD
FRUITCORE M - MEDIAN PYRUS.CORVALLIS.STD
GRIT 3 - (1 = NO STONE CELLS, 9 = MANY STONE CELLS) PYRUS.CORVALLIS.STD
GRIT_SIZE S - SMALL PYRUS.CORVALLIS.STD
GROUND_COLOR Y - YELLOW PYRUS.CORVALLIS.STD
LENTICEL_SIZE 3 - (1 = SMALL, 9 = LARGE) PYRUS.CORVALLIS.STD
LENTICELS 3 - (1 = FEW, 9 = MANY) PYRUS.CORVALLIS.STD
OVER_COLOR BL - BLUSH PYRUS.CORVALLIS.STD
OVER_COLOR ST - STRIPPED PYRUS.CORVALLIS.STD
OVERCOLOR_AMT 15 PYRUS.CORVALLIS.STD
OXIDATION 1 - NONE PYRUS.CORVALLIS.STD
PEDICEL_ATTACHMENT U - SUNKEN PYRUS.CORVALLIS.STD
QUALITY 6 - (1 = POOR, 9 = EXCELLENT) PYRUS.CORVALLIS.STD
RUSSET 6 - (1 = NONE, 9 = COMPLETELY RUSSETED) PYRUS.CORVALLIS.STD
RUSSET_LOCATION B - BLUSH SIDE PYRUS.CORVALLIS.STD
RUSSET_LOCATION C - CALYX END PYRUS.CORVALLIS.STD
TEXTURE_TYPE C - CRISP PYRUS.CORVALLIS.STD
PHENOLOGY Descriptors
FIRST_BLOOM 87 PYRUS.CORVALLIS.1986
FIRST_BLOOM 88 PYRUS.CORVALLIS.1987
FIRST_BLOOM 89 PYRUS.CORVALLIS.1988
FIRST_BLOOM 92 PYRUS.CORVALLIS.1988
FIRST_BLOOM 102 PYRUS.CORVALLIS.1989
FIRST_BLOOM 92 PYRUS.CORVALLIS.1990
FULL_BLOOM 93 PYRUS.CORVALLIS.1987
FULL_BLOOM 99 PYRUS.CORVALLIS.1988
FULL_BLOOM 105 PYRUS.CORVALLIS.1989
FULL_BLOOM 96 PYRUS.CORVALLIS.1990
FULL_RIPE 275 PYRUS.CORVALLIS.1987
FULL_RIPE 247 PYRUS.CORVALLIS.1990
LAST_BLOOM 105 PYRUS.CORVALLIS.1987
LAST_BLOOM 106 PYRUS.CORVALLIS.1987
LAST_BLOOM 108 PYRUS.CORVALLIS.1988
LAST_BLOOM 196 PYRUS.CORVALLIS.1988
LAST_BLOOM 116 PYRUS.CORVALLIS.1989
LAST_BLOOM 103 PYRUS.CORVALLIS.1990
More importantly many of the trees are virus infected in the case of PI 541173 its infected with P. communis ‘Nouveau Poiteau’. The USDA will later remove the virus through this process http://www.ars-grin.gov/cor/reprints/Postman.2002.ActaHort.596.pdf. Not everyone is familiar with this information so I thought it might help to discuss the website.