FUCHSIA PROBLEM
Response to Don Hesels request for help
By Mike Altman
Verticillium Wilt
Response to Don Hesels request for help
By Mike Altman
Verticillium Wilt
In the January – March issue
of the American Fuchsia Society
Bulletin I reported a problem
with fuchsias encountered
here in the Crescent City area.
See (A Fuchsia Problem, I Need
Help, page 17). Specifically,
fuchsias dying, a branch at a
time, under what appeared to
be ideal growing conditions. I
received several responses via
e-mail, all of which were helpful,
however one really hit the
bulls eye.
Mike Altman, from Spokane, Washington offered the following: Verticillium Wilt
Verticillium wilt is caused by the fungi Verticillium alboatrum and Verticillium dahliae. These fungi live in the soil and attack plants whose roots are stressed. These fungi may attack more than three hundred woody and herbaceous plant species. Plant susceptibility or resistance may vary from one region to another since the virulence found in the different strains of Verticillium sp. is usually different as well as the genetic resistance of the plant. Cultural practices and environmental conditions can influence the infection of susceptible plants with this disease.
Barberry, boxwood, stone fruit trees such as peach and plum, Kentucky coffee tree, horse-chestnut, Ohio buckeye, magnolia, maple, peony, privet, redbud, serviceberry, smoke tree/bush, spirea, sumac, tulip tree, viburnum and many herbaceous plants such as tomato, strawberry and many weeds are examples of susceptible plants. Some examples of resistant plants include all monocots, all gymnosperms, apple, crabapple, mountain ash, beech, birches, dogwood, hackberry, hawthorn, linden, honey locust, oaks, sycamore, popular, walnut, and willow.
Symptoms
The plant symptoms that result
when this disease attacks
may be confused with other
plant problem symptoms such
as fusarium wilt, bacterial wilt,
root rots as well as drought
and damage due to excessive
soil moisture. In Illinois, the
disease is more severe in cool
to warm weather and is not as
prevalent in hot weather.
Plant leaves may curl, wilt, yellow or redden interveinally, die and defoliate. Individual branch die back may also be noticed. The disease starts in the roots and then progresses upward. As the vascular system becomes plugged due to the release of tyloses or gums, the above ground symptoms begin to appear.
Internally, discoloration or streaking of the sapwood (xylem vascular tissue) occurs in most plants. The sapwood discoloration may appear as a striping of the wood when viewed on a branch with the bark peeled away. If the branch or plant is cut and the cross section examined, the discoloration may appear as a ring. The vascular discoloring often occurs with the advance of the fungus or the fungal spores through the sapwood except sometimes in the early stages of infection. Vascular discoloration varies with the host. In all ashes, internal discoloration is rare. In black locust the color is a dark reddish brown, it is a yellowish brown in cherry and smoke trees and is a light- to darkgreen in maple, magnolia and sumac.
Although some plants may die quickly, more commonly it takes one or more years to die. Trees and shrubs with only a few wilted branches during a growing season may become more severely infected the following year. Some may recover and show no more symptoms in the following years or the disease may cause the plant to develop symptoms years later.
In herbaceous plants, the older and lower leaves turn yellow, wilt and wither. In young herbaceous plants, plants are stunted and die prematurely. Wilting during the day with recovery at night may be common for a while.
Control
Grow plants adapted to the site. Grow resistant varieties and species. Avoid root and collar injury. Keep plants vigorous. Trees, shrubs and herbaceous plants killed by Verticillium spp. should be removed with as much of the roots intact as possible. Plants showing early symptoms should be watered and fertilized. Use fertilizers lower in nitrogen and higher in potassium. Sterilize tools between pruning and removal of infected plants and pruning healthy plants. Allow several years before growing a susceptible plant in an infected area. Do not plant back into the same hole! There are no proven cures (chemical or cultural) for this disease.
Written by James Schuster, Extension Educator, Horticulture, and reviewed by Bruce Palsrud, Extension Specialist, Pesticide Applicator Training, Department of Crop Sciences, University of Illinois at Urbana- Champaign.
Here are some suggestions for solving future fuchsia problems.
I might respectfully suggest that you contact the Del Norte County Coop Extension program and talk with an employee who is conversant with bacterial infection in plants. If no one is available at the coop extension offi ce who feels confi - dent to diagnose your problem, then ask if the coop extension employee had that problem, where would he or she go to solve it.
You might consider contacting the nearest Land Grant College or University in the area, i.e., Humboldt State. Ask for their horticulture department and talk to the professors about your fuchsia problem. You might be asked to bring in a specimen so that it could be examined under a microscope.
Perhaps the Master Gardener program, if there is one in Del Norte County, might assist you. They do research on gardening questions and love to research problems to achieve answers. Regards, Mike Altman, Spokane, WA
Mike Altman, from Spokane, Washington offered the following: Verticillium Wilt
Verticillium wilt is caused by the fungi Verticillium alboatrum and Verticillium dahliae. These fungi live in the soil and attack plants whose roots are stressed. These fungi may attack more than three hundred woody and herbaceous plant species. Plant susceptibility or resistance may vary from one region to another since the virulence found in the different strains of Verticillium sp. is usually different as well as the genetic resistance of the plant. Cultural practices and environmental conditions can influence the infection of susceptible plants with this disease.
Barberry, boxwood, stone fruit trees such as peach and plum, Kentucky coffee tree, horse-chestnut, Ohio buckeye, magnolia, maple, peony, privet, redbud, serviceberry, smoke tree/bush, spirea, sumac, tulip tree, viburnum and many herbaceous plants such as tomato, strawberry and many weeds are examples of susceptible plants. Some examples of resistant plants include all monocots, all gymnosperms, apple, crabapple, mountain ash, beech, birches, dogwood, hackberry, hawthorn, linden, honey locust, oaks, sycamore, popular, walnut, and willow.
Plant leaves may curl, wilt, yellow or redden interveinally, die and defoliate. Individual branch die back may also be noticed. The disease starts in the roots and then progresses upward. As the vascular system becomes plugged due to the release of tyloses or gums, the above ground symptoms begin to appear.
Internally, discoloration or streaking of the sapwood (xylem vascular tissue) occurs in most plants. The sapwood discoloration may appear as a striping of the wood when viewed on a branch with the bark peeled away. If the branch or plant is cut and the cross section examined, the discoloration may appear as a ring. The vascular discoloring often occurs with the advance of the fungus or the fungal spores through the sapwood except sometimes in the early stages of infection. Vascular discoloration varies with the host. In all ashes, internal discoloration is rare. In black locust the color is a dark reddish brown, it is a yellowish brown in cherry and smoke trees and is a light- to darkgreen in maple, magnolia and sumac.
Although some plants may die quickly, more commonly it takes one or more years to die. Trees and shrubs with only a few wilted branches during a growing season may become more severely infected the following year. Some may recover and show no more symptoms in the following years or the disease may cause the plant to develop symptoms years later.
In herbaceous plants, the older and lower leaves turn yellow, wilt and wither. In young herbaceous plants, plants are stunted and die prematurely. Wilting during the day with recovery at night may be common for a while.
Grow plants adapted to the site. Grow resistant varieties and species. Avoid root and collar injury. Keep plants vigorous. Trees, shrubs and herbaceous plants killed by Verticillium spp. should be removed with as much of the roots intact as possible. Plants showing early symptoms should be watered and fertilized. Use fertilizers lower in nitrogen and higher in potassium. Sterilize tools between pruning and removal of infected plants and pruning healthy plants. Allow several years before growing a susceptible plant in an infected area. Do not plant back into the same hole! There are no proven cures (chemical or cultural) for this disease.
Written by James Schuster, Extension Educator, Horticulture, and reviewed by Bruce Palsrud, Extension Specialist, Pesticide Applicator Training, Department of Crop Sciences, University of Illinois at Urbana- Champaign.
Here are some suggestions for solving future fuchsia problems.
I might respectfully suggest that you contact the Del Norte County Coop Extension program and talk with an employee who is conversant with bacterial infection in plants. If no one is available at the coop extension offi ce who feels confi - dent to diagnose your problem, then ask if the coop extension employee had that problem, where would he or she go to solve it.
You might consider contacting the nearest Land Grant College or University in the area, i.e., Humboldt State. Ask for their horticulture department and talk to the professors about your fuchsia problem. You might be asked to bring in a specimen so that it could be examined under a microscope.
Perhaps the Master Gardener program, if there is one in Del Norte County, might assist you. They do research on gardening questions and love to research problems to achieve answers. Regards, Mike Altman, Spokane, WA