A pathogen, a host, and the right environment: these are the ingredients needed to spark plant disease. This is a simple formula, which can have devastating results for a grower. Infamous greenhouse diseases including botrytis (gray mold), powdery mildew, late blight, and downy mildew are known to decimate crops as well profitability.

humidity disease pyramid

The plant disease triangle

If all three of these conditions exist simultaneously for the appropriate amount of time, the result will be the development of plant disease.

Disease susceptibility

Greenhouse crops can be especially at risk for the formation of crop diseases. This is due to the unique characteristics created in the greenhouse environment including:

Conditions like these make greenhouses very comfortable for pathogens to settle in and inflict disease. The impact of these outbreaks leads to yield and quality loss, increased pesticide use and additional expenses.

Proper management can eliminate greenhouse diseases

However, if properly managed, the greenhouse actually offers ways to prevent diseases. Greenhouses, by definition, create an internal environment of their own. Greenhouse growers have the unique ability to manipulate the conditions within the facility to their advantage. Herein lies the key to preventing the potentially devastating effects of plant disease. By removing one side of the triangle, growers can inhibit disease outbreaks.

This can be done in a number of ways. The isolation a greenhouse creates from the outdoor environment can help to restrict the introduction of pathogens to the plants. Sanitation measures such as disinfecting growing mediums and equipment can also prevent exposure and spread of disease in the greenhouse. Temperatures can be adjusted to levels that are outside of the ranges favorable to disease development.

A critical factor in preventing greenhouse disease is proper management of humidity levels. Many pathogens require high humidity levels and the resulting water on the surfaces of the plant in order to attack plants. Keeping humidity levels in the greenhouse low is a crucial tool growers have for preventing disease outbreaks.

Using dehumidification to combat plant disease

DryGair offers dehumidification solutions for greenhouses and closed growing facilities. The system extracts excess humidity from the greenhouse and circulates the air uniformly throughout the space, to prevent the formation of wet microclimates and provide the optimal conditions to prevent humidity diseases. This is an energy efficient solution targeted at preventing disease before it can develop.

Greenhouse growers have the power to create the environment that they want within their facility. A knowledge of the pathogen biology, interactions between the pathogen-host-and environment, and the tools available at hand give the grower an upper advantage when it comes to disease management. Breaking the triangle is the key to preventing disease, and producing healthy, high-quality crops.