Integrated Pest Management for Raspberries

A Guide for Sampling and Decision-Making for Key Raspberry Pests in Northwest Washington

Y THROUGH EARLY JULY)OM/PRE-HARVEST (LATE MAY THROUGH EARLY

PEST	BRIEF DESCRIPTION	DAMAGE/REASON FOR CONCERN	MONITORING APPROACHES	DECISION POINTS/ TOLERANCE	MANAGEMENT OPTIONS	FOLLOW UP
Spur Blight	Overwinters as cracked gray areas on canes around buds. Tiny black pimples form in affected areas. Key infection period is in early summer. Disease Cycle	Inoculum for summer foliar infection of floricanes and primocanes. Can damage leaves on fruiting laterals and weaken buds on primocanes.	Evaluate fruiting canes to rate the severity of past disease incidence (overwintering lesions).	Disease prevention based partly on field history.	Dormant Lime Sulfur at bud swell. Early summer, pre-bloom fungicide.	Check fruiting lateral foliage for infection particularly in wet years just before and during harvest.
Cane Blight	Reddish vascular lesion below bark extends up cane from wounds associated with catcher plate damage. Need to scrape cane to expose vascular layer. Disease Cycle	If serious, can girdle or weaken the fruiting cane.	Inspection of fruiting canes by scraping away bark at catcher plate height to see reddish vascular tissue beneath.	Detection confirms need for harvest period and post-harvest disease management.	Avoid overhead irrigation as spores are rain splashed.	Watch closely during and after harvest.
Yellow Rust	Orange-yellow fruiting structures produced on upper leaf surface.	Premature death of leaves on fruiting canes. Reduced winter hardiness.	Starting in late April, examine older leaves near the wire for infection. Integrate into mite sampling procedure. Record number of infected/10 leaflets.	Consider field history, # leaflets infected and degree of infection.	Liquid lime-sulfur as delayed dormant application if present the previous year. Consider fungicides based on disease severity and wet weather conditions.	Continue to examine leaves for infection as part of mite sampling.
Cane Botrytis	Brownish tan lesions on canes. May contain black bodies called sclerotia which produce spores which infect blossoms. Disease Cycle	Weakens canes. Source of inoculum for blossoms and fruit.	Examine canes for lesions and sclerotia.	Presence of overwintering sclerotia and sporulation indicates potential for blossom infection.	Early bloom foliar fungicide to protect blossoms from infection.	Fruit inspection during harvest period.
Phytophthora Root Rot	Soilborne fungus which can cause root and crown rot. Infection favored by saturated soil conditions. Diseased plants have lack of feeder roots, poor vigor canes. Interior of major roots and crown are brown to black.	Kills infected plants through root and crown destruction. Reduced vigor and yield.	Note any water saturated/low areas following wet winters in March and April.	History of root rot problems. Consider varietal susceptibility.	Fall/spring soil applied fungicide if Phytophthora is the confirmed cause. Plant in raised beds on well-drained soil, using certified plants.	Watch for symptoms just prior to and during harvest on both fruiting canes and primocanes.

G.W. Menzies & C.B. MacConnell, WSU Cooperative Extension Whatcom County
June 1998

Funded in part by: Washington State Department of Ecology through U.S. Environmental Protection Agency, Section 319 Funds