Chapter 6-11 Flashcards
Conidia
are asexual spores produced on specialized hyphae known as a conidiophore
Sporodochium
a superficial, cushion-shaped asexual fruiting body consisting of a cluster of conidiophores
Synnema
compact or fused, generally upright conidiophores, with branches and spores forming a headlike structure
Acervulus
an erumpent, cushionlike fruiting body bearing conidiophores, conidia, and sometimes setae
Pycnidium
an asexual, globose or flask-shaped fruiting body containing conidia
Ascomycota Asexual Reproductive Structures
A. Sporodochium B. Synnema C. Acervulus D. Pycnidium
Ascomycota Sexual Reproductive Structures
Ascospores, Apothecium, Chasmothecium/Cleistothecium ,Perithecium, Pseudothecium
Ascospores
(4 to 8) within an ascus (sac fungi)
Apothecium
an open, cuplike or saucerlike, ascus-bearing fungal fruiting body (ascocarp), often supported on a stalk
Chasmothecium/Cleistothecium
a spherical ascocarp that is closed at maturity
Perithecium
a flask-shaped or subglobose, thin-walled fungus fruiting body (ascocarp) containing unitunicate asci and ascospores
Pseudothecium
a perithecium-like fruiting body containing bitunicate asci in unwalled locales or cavities
Peach leaf curl – Taphrina deformans
Symptoms – thickened curled red or yellow colored leaves in the spring, may blight shoots and cause lesions on fruit if severe
Peach leaf curl management
- Available resistant varieties include Frost, Indian Free, Muir, and Q-1-8
- One fungicide application between leaf fall and bud swell
- Conventional–Ziram–Chlorothalonil–Fixed copper •Organic–Bordeaux mixture–Some copper compounds
Apple scab – Venturia inequalis
Symptoms: Lesion mostly on leaves and fruit first appears as a lighter shade of green and is circular, lesions increase in size it becomes olive-colored and velvety due to production of asexual spores
Apple scab management
- Cultural –fall foliar application of urea–chopping fallen leaves does not improve control in Cal–remove neighboring crab apples
- Host resistance – available but not popular varieties
- Chemical protection – fungicide applications to prevent primary infections
Powdery mildew of lettuce – Erysiphe cichoracearum
Signs: White powdery growth on upper and lower leaves, and small brown/black spots (chasmothecia)
–Symptoms: In advanced stages leaves dry out and become brown
Powdery mildew of lettuce Management
•Begin fungicide treatments as soon as symptoms are observed –Sulfer –Azoxystrobin
Strawberry anthracnose – Colletotrichum acutatum
Symptoms: White to light brown water soaked spots on fruit – sunken, lesions on leaves and stems, crown tissue may decay and may have a mass of salmon colored spores, stunting and chlorosis may occur
Strawberry anthracnose management
- Soil fumigation and solarization
- Fungicide dips prior to planting
- Rotate to non-host crop – broccoli or mustards•Disease free plantings
- Proper irrigation – minimize overhead irrigation
- Remove infected plant parts
Brown rot – Monilinia fructicolaand M. laxa
–Symptoms – blossom blight and ripe fruit phases, mummies–
Signs – gray brown spore masses on blighted tissue, apothecia on mummies in spring
Brown rot management
- Cultural – reduce inoculum by removing mummies, pruning out twig cankers
- Host resistance – varies from susceptible to very susceptible
- Chemical protection – fungicide applications during bloom and again during ripening if conditions conducive
Watery soft rot/ cottony rot – Sclerotinia sclerotiorum and S. minor
–Symptoms – Soft rot, stem rot, damping-off, flower blight–
Signs – fluffy white mycelium and black irregular sclerotia on plant, soil line or stems and petioles, apothecia develop following cool and wet weather
Watery soft rot/ cottony rot management
- Exclusion - avoid introducing to new fields•Eradication - 2-3 year crop rotation in coastal areas (S. sclerotiorum ascospores airborne)
- Cultural Practices – Avoid overly wet fields, keep surface of beds dry, canopy management, tillage, remove weed hosts
- Biological – Several fungal species are parasitic •Chemical protection – vinclozolin (Ronilan), iprodione (Rovral) or dichloran (Botran)
