Say the word “fungus” and most people think of negative things—moldy bread, deadly toadstools, plant diseases in the garden or nasty skin infections. Although many fungi can be harmful to people, animals and plants, the vast majority are actually essential to the functioning of the ecosystem. These helpful fungi are the overlooked, “unsung heroes” of the natural world.
The cooler fall temperatures bring welcome relief from the summer heat. As we trade bare feet for shoes, the grass underfoot in our lawns is relieved to see some cooler, wetter weather. But the autumn weather also makes many fungi happy, and several fungal diseases of lawns may show up this time of year.
Willows and poplars are common trees for use in windbreaks or privacy screens because they grow very fast, providing effective screening within a few years. One of the most popular willows is the Austree, a hybrid willow (a cross of white willow and corkscrew willow) developed in New Zealand. However, many people are dismayed when these beautiful screens start declining and dying after a dozen or years, or even sooner. These fast-growing trees exemplify the saying, “live fast, die young” because, despite their fast growth, they are highly susceptible to several lethal diseases.
Spruces are a favorite evergreen for yards and windbreaks in Iowa. However, they are susceptible to a few problems that can leave them unsightly. Knowing about these common spruce ailments is the first step toward minimizing problems with these beautiful trees.
A walk through the forest at this time of year may lead to the discovery of what appear at first glance to be giant marshmallows. A closer investigation reveals that the spheres are composed of a soft spongy material – rather than a soft sticky material. These objects are puffballs, produced by certain soil-dwelling fungi. There are a number of different species of fungi that form puffballs and they can be found growing on the ground in forests, pastures and lawns.
My neighbor’s ‘Tiger Eyes’ sumac has produced several suckers. Can I dig up one of the suckers and plant it in my yard?
What is the common name of the tree that produces yellow-green hedge balls?
My ‘Sunburst’ locust is not growing well. What could be the problem?
Late summer/early fall is the time of the year when leaves of bur oaks in Iowa are showing V-shaped brown discoloration and browning of the leaf veins. The affected leaves eventually die and fall to the ground or hang dead on the twigs through the winter and into the following year. The disease may affect the entire tree and if only a portion of the tree is affected, the disease is generally most severe in the bottom of the tree.
Gray mold caused serious losses to some greenhouse growers of raspberries in Iowa last year. Gray mold or Botrytis blight is caused by the fungus Botrytis cinerea, which has a wide host range with over 200 reported hosts among ornamentals plants, vegetables and fruits. In addition, Botrytis can cause different kinds of plant diseases, attacking seedlings, flowers, fruits, stems and foliage. It is also a major cause of postharvest rot in fruits. The disease can occur in the greenhouse as well as in the field when weather is humid and cool.
A project assessing the impact of mycotoxins – toxic chemicals produced by fungi found in food crops is slated to begin mid-March. Little research has been undertaken on this issue in Rwanda, and the hope is to gain knowledge needed to help quantify the amount of mycotoxins found in the food chain.