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DISEASE CONTROL - CULTURAL CONTROL

SANITATION

Keeping your garden, work areas and tools clean is a fundamental and important means of pathogen/disease control.

DISINFEST TOOLS

In general, you should make a habit of cleaning and disinfesting your gardening tools when moving from area to area in your garden. This can be particularly critical when you have been working in an area where you have historically had disease problems. It is also important to disinfect pruning shears as you move from tree to tree or from shrub to shrub. Sometimes you may even want to disinfest pruning shears between cuts on the same tree or shrub. By disinfesting your tools, you reduce the chance of moving pathogens from place to place in your garden.

To disinfest tools, use a 10% bleach solution, alcohol or another disinfectant. Often people ask whether Lysol spray will work. It should because the major ingredient is alcohol.

ADEQUATELY CLEAN POTS AND BENCHES

Dirty pots and workbenches can serve as reservoirs of plant pathogens. Wash bench tops thoroughly, then disinfest with a 10% bleach solution or another disinfectant. To disinfest clay pots, wash them thoroughly, then soak them for a minimum of 20 minutes in a 10% bleach solution. Be cautious when reusing plastic pots. Some research indicates that some root rot pathogens (e.g., Pythium and Phytophthora) can survive in plastic, even after soaking in 10% bleach.

USE PASTEURIZED SOIL

Root rot pathogens are often found in field soils, so use of this soil for houseplants is not recommended. Use commercially available PASTEURIZED soils for transplanting. These soils are less likely to contain plant pathogens than field soils, and are more suited for growth of interior ornamentals.

DECONTAMINATE RECYCLED WATER

If you work in a greenhouse and like to conserve water by recycling, be sure to decontaminate recycled water prior to use. Filtering and ultraviolet radiation treatments are available for this purpose.

REMOVE DISEASED PLANTS PROMPTLY

Diseased plants can serve as a source of inoculum for other plants. Therefore removing infected plants can reduce disease by reducing inoculum.

REMOVE SCENSCENT (DYING) PLANT PARTS PROMPTLY

Several pathogens (in particular Botrytis, a common fungal pathogen on ornamentals) have difficulty directly infecting healthy plant tissue. They can however, readily infect scenescing (dying) tissue. In particular, petals that are withering and falling off are prime targets for infection. Once these pathogens have a foothold in senescing tissue, they can then much more easily infect healthy tissue. Greenhouse growers often see Botrytis leaf infects where a withered petal has fallen onto a leaf. The fungus is able to infect the withered petal, then uses this as a food base to attack the leaf. Removal of senescing tissue can significantly inhibit development of this disease, by preventing initial infections.