Integrated pest management resources for Michigan Michigan State University home IPM Michigan home
IPM Scouting in Herbaceous Perennials

Search

Christmas trees
Field crops
Fruit
Home and yard
Nursery and landscape
Turfgrass
Vegetable


Diagnostic Services
Soil/Plant Nutrient Lab
Enviro-weather
Regional IPM Center
Pesticide safety
Organic: New Ag Network
Invasive species
Sustainable ag & food systems


MSU ANR departments
MSU Extension

Site index
Contacts/permissions

Botrytis blight
IPM scouting in herbaceous perennials > botrytis blight
Pathogen: Botrytis cinerea.

Hosts: Very large host range, some of the most susceptible include Delphinium, Hosta, Iris, Lilium, Primula, Rudbeckia and Viola. Blossoms are especially susceptible.

Symptoms: Seedling blight, leaf spots and blight, distortion of young leaves, crown rot and blossom blight.

Signs: In high relative humidity, grayish, fuzzy mold on the surface of the affected tissue is visible with the naked eye.

Spread: Spores are produced in mass under humid conditions and are readily released and moved by air currents. Additionally, overwintering structures (sclerotia) are formed and can persist in soil and plant debris. Sclerotia are found on the surface of heavily diseased plant material.

Management: Sanitation and aeration procedures that reduce humidity levels around plants and appropriate fungicide applications are recommended for disease control. Botrytis cinerea can sporulate on dead plant material; fallen leaves and petals should be carefully removed from production areas. Trash cans used for dead plant tissue should not be kept in production areas. Regular fungicide applications will likely be necessary to reduce losses on especially susceptible hosts grown in humid environments.
Basal end of cutting Sclerotia on dead stem tissue
Basal ends of cuttings can be infected during propagation. The gray, fuzzy mold is characteristic of B. cinerea sporulation. Sclerotia, the overwintering structure, on dead stem tissue.
Severe leaf spotting Severe leaf spotting Foliar blighting
Severe leaf spotting. Infections develop-ed during prolonged, wet weather. Severe leaf spotting on Lilium, a very susceptible host. Foliar blighting of Rudbeckia.
This information was developed from A Pocket Guide for IPM Scouting in Herbaceous Perennials by Jan Byrne and Raymond A. Cloyd. Purchase this in a pocket-sized guide for reference in the orchard from MSU Extension (publication E-2981).
The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the Michigan Agricultural Experiment Station, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.
Email
the web developer.
Updated 9/28/07