Plant Disease Management and Prevention Strategies
Three factors must exist for plant disease development: 1. a pathogen (disease causing agent), 2. a susceptible host plant, and 3. an environment that favors disease.
Viruses and mycoplasmas are microscopic disease causing agents most often spread by insects flying or hopping from one plant to another but also by people handling infected plant parts or infected cuttings. Few chemical controls are available for viruses. Plants with symptoms of viral infection should be uprooted and discarded. Seeds and cuttings from infected plants carry the viral infection, too. Antibiotics can be used to control a few mycoplasma diseases and to slow down the development of bacterial infections.
Bacteria are one celled organisms. Bacteria may be introduced to a site in the form of infected cuttings or seeds. Bacteria move between plants via splashing water or on tools and equipment.
Fungi are responsible for many plant diseases. Fungal-based root infections cause rot, wilting and death of the plant. Stem and twigs may be infected by fungi which cause blight, cankers, and dieback. Foliage, needles, fruit and flowers affected by fungal diseases may display spots, blisters, distorted structures and dead tissue.
Most fungi are spread by spores which move with the help of wind, water, insects and people or tools which come in contact with infected plant parts. Once plant tissues are damaged by a fungal disease no remedy is available to return them to perfect health.
Typical fungus controls are sprayed on healthy plant parts to form a protective barrier against the spread of infection. Heavy or wind-driven rain washes away part of the protection hampering control efforts and requiring another application before each upcoming storm.
Choosing disease resistant cultivars is the first line of defense. Weak, damaged or wounded plant parts are more susceptible. Use proper pruning and cultural practices to promote healthy, vigorous plants less likely to succumb to infection. Gardeners should also remove and dispose of plant parts showing symptoms as they are a source of pathogens.
During extended rainy periods, don’t miss an opportunity to spray before upcoming rains. Home orchard sprays should be applied now to prevent peach scab, cedar-apple rust (apple infections are possible through early to mid-May), and apple scab.
Like this post? Subscribe to my RSS feed and get loads more!