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Pear Scab

Venturia pirina

0 host plants · Fungal

Last updated

Data Coverage 2 of 6 dimensions
Causal Agent
Host Plants
Symptoms
Management
GDD Threshold
Regional Notes

Quick Reference

Agent Type
fungal
Causal Agent
Venturia pirina
Host Plants
0
Spread
rain-splash, wind
Favorable Conditions
Primary infection requires rain or prolonged leaf wetness during the ascospor...

Regional Season Tracker

GDD₃₂ accumulation across 7 Puget Sound stations · as of Mar 19, 2026
Station GDD₃₂ Current Stage Next To Go
Seattle / UW 969 Scab season begins (early ascospore release) Ascospore maturity (~100%) 651
Issaquah / East King 959 Scab season begins (early ascospore release) Ascospore maturity (~100%) 661
Olympia / Tumwater 906 Scab season begins (early ascospore release) Ascospore maturity (~100%) 714
Bellingham / Whatcom 902 Scab season begins (early ascospore release) Ascospore maturity (~100%) 718
Kent / Auburn 894 Scab season begins (early ascospore release) Ascospore maturity (~100%) 726
Sequim / Rain Shadow 885 Scab season begins (early ascospore release) Ascospore maturity (~100%) 735
Tacoma / Puyallup 877 Scab season begins (early ascospore release) Ascospore maturity (~100%) 743

Note: Ascospore maturity predicted by GDD; actual infection events require rain or prolonged leaf wetness at susceptible temperatures.

Developed in Oregon. Strongest regional fit of any disease GDD model in the HFG system. No separate Western Washington validation, but climate is more comparable than continental models. Maritime Puget Sound may accumulate GDD more slowly in early spring than Hood River.