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2022 Pear Psylla Degree Day Table

Authors: Louis Nottingham, Robert Orpet, WSU Entomology. March 1, 2022

See the Pear Psylla Phenology Model page for conventional and organic guidelines on current and future pear pest management.

2022 Pear Psylla Degree Days (PDD), Updated Weekly

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2022 Cashmere Omak Peshastin Wapato Wenatchee Hood River Medford
28-Feb 57 6 48 92 55 113 313
7-Mar 99 27 78 146 95 161 354
14-Mar 125 48 95 183 123 196 408
20-Mar 160 80 120 220 159 228 447
27-Mar 240 143 188 298 242 308 542
3-Apr 310 208 246 372 321 372 615
10-Apr 353 253 273 419 368 409 681
17-Apr 365 274 281 427 382 424 704
24-Apr 419 324 322 483 442 474 762
1-May 491 391 377 555 523 532 832
8-May 575 483 442 639 620 606 907
15-May 646 552 497 721 705 680 983
22-May 738 647 573 821 812 768 1085
29-May 869 773 678 950 952 887 1215
5-Jun 1006 926 804 1095 1103 1035 1343
12-Jun  1152 1079 931 1258  1266  1173  1506
19-Jun 1282 1215 1042 1390 1418 1290 1613
26-Jun 1463 1397 1204 1570 1624 1465 1798
3-Jul 1668 1605 1387 1788 1845 1649 1983
10-Jul 1853 1793 1552 1990 2049 1830 2183
17-Jul 2084 2017 1757 2213 2295 2035 2407
24-Jul 2316 2243 1971 2437 2544 2242 2616
31-Jul 2573 2506 2221 2692 2811 2494 2875
7-Aug 2793 2724 2422 2900 3050 2710 3113
14-Aug 3031 2970 2645 3128 3302 2904 3324
21-Aug 3285 3226 2887 3371 3559 3110 3549
28-Aug 3515 3449 3103 3588 3803 3306 3767
4-Sep 3741 3663 3317 3800 4037 3489 3984
11-Sep 3917 3842 3479 3969 4229 3641 4200
18-Sep 4072 3998 3623 4119 4392 3770 4355
25-Sep 4228 4148 3763 4264 4562 3893 4518
2-Oct 4397 4313 3923 4426 4742 4030 4685
9-Oct 4560 4481 4082 4588 4907 4168 4869
16-Oct 4696 4613 4210 4720 5047 4282 5029
23-Oct 4782 4683 4295 4804 5137 4359 5139
30-Oct 4837 4738 4338 4866 5196 4410 5199

Pear Psylla Degree Days and Management Timings

graph showing the different lifestages of pear psylla against degree days

Contact:

Louie Nottingham

Dr. Louis Nottingham
Assistant Professor
WSU Tree Fruit Research & Extension Center
1100 N Western Ave., Wenatchee, WA 98801
louis.nottingham@wsu.edu
540-798-2044 (cell)

Robert Orpet

Dr. Robert Orpet
Postdoctoral Research Associate
WSU Tree Fruit Research & Extension Center
1100 N Western Ave., Wenatchee, WA 98801
robert.orpet@wsu.edu

This Project was Funded by:

fresh and processed pear committee logo.

 

 

 

Disclaimer: 

Use pesticides with care. Apply them only to plants, animals, or sites listed on the labels. When mixing and applying pesticides, follow all label precautions to protect yourself and others around you. It is a violation of the law to disregard label directions. If pesticides are spilled on skin or clothing, remove clothing and wash skin thoroughly. Store pesticides in their original containers and keep them out of the reach of children, pets, and livestock.

YOU ARE REQUIRED BY LAW TO FOLLOW THE LABEL. It is a legal document. Always read the label before using any pesticide. You, the grower, are responsible for safe pesticide use. Trade (brand) names are provided for your reference only. No discrimination is intended, and other pesticides with the same active ingredient may be suitable. No endorsement is implied.

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