BOTRYTIS: Controls

A condition of high humidity over twelve hours causes the spores to sprout and causes death of cells; it sporulates off dying or dead organic matter; maintain night temperatures in mid- to upper-50's dF to dry the air; for details refer to OA80-140

Botrytis cineraria is a fungus easily controlled by Benlate spray on plants and stems (it spots the flowers); plus cleanliness and good air movement. A82-690

It is common in fall and spring when night temperatures are in the 50's dF with high humidity, when water condenses on the plants and flowers, where spores can germinate in four hours and penetrate, causing ugly spotting; stop the droplets from forming either by increasing air movement or by higher temperature. A83-343

Spray Benlate three times at fortnightly intervals and monthly thereafter; clean up the greenhouse. OR81-101

Use Benlate spray, occasionally alternated with Fore, or Dithane M-45; Ornalin, and Chipco 26019 are other recently introduced controls. AH86-70

Use Captan WP at lttpg.; Banrot WP at ltpg.; Physan at Itpg.; Benlate WP at 1/2 tpg. OD87-35

Use the fumigant Exotherm Termil weekly, keep the air moving day and night. A81-1197

Botrytis	Comments
BOTRYTIS: Cause and Cure An ever-present fungus; causes small round brown spots on flowers; decaying organic matter under the bench is a good source; best control is to keep water off the flowers; give good air circulation. A60-293; AH35; OD71-198	0
BOTRYTIS CINEREA: A Saprophyte Flourishes on decaying leaves, flowers, flower sheaths, leaf axils, organic debris on benches and floors, multiplies under conditions of excessive damp and cold; produces unsightly brown to black spots on flowers. OD67-49	0
BOTRYTIS: Flower Spotting Caused by Botrytis cinerea; occurs generally on cymbidiums, but also infects cattleyas and phalaenopsis; cool conditions favor infection (45 to 65 deg, F); clean culture is essential; to date no chemical control available; Termil fumigation partly successful. A68-227+	0
BOTRYTIS: On Orchid Blossoms Fungus spores germinate during humid conditions, usually at night; there are six kinds that do this; a drop in humidity plus clear days will stop development; fans that produce gentle but definite air movement help. A65-536; on leaves. A64-58	0
BOTRYTIS: Petal Blight It can affect flowers in moist, cool and stagnant air; increase air movement and ventilation; spray with Benlate or Physan 20; illus. A66-558; A75-907 (illus); A77-436; cut off flowers. S204	0
BOTRYTIS: Time Lag to Its Visibility It takes normally 10 to 12 hours to show on cattleya flowers. A80-110	0

Botrytis

Comments

BOTRYTIS: Cause and Cure An ever-present fungus; causes small round brown spots on flowers; decaying organic matter under the bench is a good source; best control is to keep water off the flowers; give good air circulation. A60-293; AH35; OD71-198

BOTRYTIS CINEREA: A Saprophyte Flourishes on decaying leaves, flowers, flower sheaths, leaf axils, organic debris on benches and floors, multiplies under conditions of excessive damp and cold; produces unsightly brown to black spots on flowers. OD67-49

BOTRYTIS: Flower Spotting Caused by Botrytis cinerea; occurs generally on cymbidiums, but also infects cattleyas and phalaenopsis; cool conditions favor infection (45 to 65 deg, F); clean culture is essential; to date no chemical control available; Termil fumigation partly successful. A68-227+

BOTRYTIS: On Orchid Blossoms Fungus spores germinate during humid conditions, usually at night; there are six kinds that do this; a drop in humidity plus clear days will stop development; fans that produce gentle but definite air movement help. A65-536; on leaves. A64-58

BOTRYTIS: Petal Blight It can affect flowers in moist, cool and stagnant air; increase air movement and ventilation; spray with Benlate or Physan 20; illus. A66-558; A75-907 (illus); A77-436; cut off flowers. S204

BOTRYTIS: Time Lag to Its Visibility It takes normally 10 to 12 hours to show on cattleya flowers. A80-110

BOTRYTIS: Controls

by Robert M. [Bert] Hamilton (Compiler)

Originally published in The Orchid Doctor in 1980 and 1988

More The Orchid Doctor Articles under the Heading Botrytis

New Topics

New Comments