Because of a wet growing season home gardeners have seen an increase in their disease problems.
According to Kathryn Kettel, University of Idaho/Nez Perce County Extension intern, when most home gardeners notice plant damage they think of insects but, disease organisms can be present and to the untrained eye these symptoms resemble insect damage.
Diseases are brought about by infectious agents like bacteria, fungi, nematodes and viruses. Symptoms of disease include death of leaves, twigs, large branches or roots. You may notice a gradual yearly decline and progressive dieback of trees or shrubs.
The gradual reduction of growth and vigor of a landscape plant in poor health is usually due to a complex of living pathogens that attack a plant weakened by environmental stresses, such as summer drought periods or soil compaction. Plants weakened from any cause may be more vulnerable to insects and disease producing organisms of low virulence.
With current concerns about pesticide safety and water quality it is time to look at alternate ways of controlling our home landscape and garden problems. When caring for your yard and garden one way to reduce pesticides is by using an Integrated Pest Management (IPM) approach. The key principle of the IPM program is to use every available method to control pests and diseases on plants. This includes the use of cultural controls and other alternatives to conventional pesticides, when practical.
Cultural controls are maintenance practices which can make the environment unfavorable for disease. Such controls include some of the oldest cultural practices known and are usually more effective for preventing pest buildup than for correcting an existing disease problem. Timing is critical to the success of most cultural pest controls.
The following cultural practices can help fight disease problems in your home garden:
*Maintain plant vigor. Plant appearance is enhanced when a plant is healthy and actively growing but can also increase tolerance to disease pathogens. The goal is moderate plant vigor through careful management of nutrition, aeration, and moisture. The optimum vigor will depend on the plants, and the environment.
*Disease-free plants should be selected. Make sure disease organisms are not introduced at the planting site. Plants and the soil in which they are moved should be free of pathogens, insects, nematodes, and weed pests.
*Sanitation in and around plants can effectively remove or destroy the breeding, refuge, and over wintering sites of pathogens. Sanitation usually involves removing infected, dead and fallen twigs, leaves and fruit.
*Species diversification in the landscape can help prevent a major outbreak of disease. If a disease problem does appear diversification can keep the disease isolated from other plants of the same variety. Species diversification can also provide alternate food sources and refuge for the natural enemies of pests.
*Avoid injury to plants. Cuts, bruises, cracks and insect damage are often sites for invasion by disease-causing organisms.
*Eliminate disease at the plant or planting level. For example, an infected plant part can be pruned off and destroyed so that the pathogen does not spread.
*Clean garden tools with alcohol after using them to prune or remove plants. The alcohol prevents the transference of disease organisms to healthy plants.
*Use of appropriate chemicals in a timely manner. Although many diseases can be controlled by cultural practices pesticides are sometimes necessary to control certain diseases and must be applied in a timely manner.