Reviewing Cultural Disease Control Practices
Kelly Ivors, Extension Plant Pathologist, NCSU/Plant Pathology
The foundation of any integrated pest management program should always include cultural and sanitation practices. Cultural management involves avoiding the onset of disease by creating an environment unfavorable to pathogens. For example, grow plants under optimum conditions. Non-living factors such as deficiencies or excess water, light, temperature, air pollution, pesticides and nutrients can predispose a plant to disease or cause direct plant injury. General cultural practices include:
- Provide adequate spacing for plants. Air movement is limited when plants are grown too close together, allowing moisture to remain on leaves for longer periods of time. Wider spacing in container areas promotes faster drying after irrigation.
- Avoid excessive soil moisture. Overwatering enhances damping-off and root rot diseases.
- Fertilize plants properly based on soil nutrient analyses.
- Discard plant debris and infected foliage outside of the greenhouse.
- Keep production areas weed-free; weeds are often pathogen reservoirs.
- Always disinfest equipment and other tools in between crops with a sanitizing solution (refer to Table 1). Surfaces should always be cleaned first with a cleaner before sanitizing. Such items would include pots, flats, trays, cutting tools, benches, carts, work areas and other related structures and equipment.
- Conduct a more thorough cleaning of greenhouse structures, surfaces and irrigation lines at the end of the growing season, then follow with a sanitizing solution (Table 1). Pressure washing walkways is good for dislodging and removing dirt. Some cleaners will remove grease and dust deposits, as well as algae in irrigation lines and water storage areas. This would include walkways, floors, walls, fan blades, ventilation ducts, watering systems, coolers and storage rooms.
- Maintain calendar records of when diseases are problematic. Scout for disease symptoms during specific times of the year based on previous history.
To lessen the impact of disease, an integrated approach to pest management must be followed; this includes the use of disease-resistant cultivars, cultural and sanitation practices, and chemical applications. Controlling most greenhouse diseases is much easier when done preventatively; good sanitation practices are extremely important in greenhouse production of plants.