Management of Plant Disease
Successful management of plant disease starts with regular monitoring of plants. It is critically important to detect diseases early so that you have a wider selection of available options to manage the diseases. Prevention is equally important in managing disease. This includes techniques like using pathogen-free or pathogen-resistant seeds or plants, eliminating disease-causing organisms from the soil before planting, and applying chemicals before diseases appear. Once a disease is detected, management of the disease can reduce the severity or spread of the disease.
Management of the disease typically requires multiple control measures to be implemented based on the biology of the pathogen and host plant. Most approaches to managing plant disease can be broken down in the five primary types of controls: regulatory, genetic, cultural, biological, and chemical.
Regulatory controls are based on exclusion of pathogenic organisms, highly susceptible host plants, and alternate host plants from a particular area. The U.S. Customs Service implements such controls to ensure unwanted pathogens and pests are not brought into the country. Plants will often be quarantined for some period to give diseases a chance to develop or a disease-causing organism to grow so that it can be detected.
Genetic controls involve breeding disease resistant plants which creates new cultivars or varieties that perform better. The genetically induced resistance might completely exclude a particular pathogen, or it may simply make it easier for the plant to overcome an infection caused by a particular pathogen.
Cultural controls have been used for a long time. Abiotic disorders are caused by non-living, environmental conditions. Cultural controls can be used to mitigate or eliminate the stress that leads to abiotic disorders. Cultural controls can also be used to prevent the conditions needed by pathogens of biotic diseases and other pests to establish themselves as well as to produce healthy, disease-free, vigorous plants. This includes such things a crop rotation to disrupt year-to-year pest cycles, sanitizing tools after using them on diseased plants to prevent further spread, planting warm seasoned crops after the soil has warmed to prevent root rot, watering lawns and gardens in the morning so they can dry during the day and remain dry through the night to prevent fungal and bacterial diseases, and pruning and training plants in such a way that it promotes airflow and more light penetration to prevent infection. These are but a few cultural controls.
Biological controls essentially involve using nature to prevent or treat diseases. One of the most common examples is using predators to control pest populations. Unfortunately, there are not a lot of these types of controls currently available.
Chemical controls involve the use of chemicals like fungicides, bactericides, and nematicides to control plant disease. Chemical controls can be effective, but it is important to properly identify the problem which may require submitting samples to a diagnostic lab for testing. Once the problem has been identified, you must determine if a chemical solution is appropriate. If so, then care should be taken to use the chemical as instructed.