Blight - Lessons for the future of pest management

Recent outbreaks of late blight spark discussion of crop disease management worldwide. DryGair offers a solution to control and prevent the conditions that lead to this outbreak.

Phytophthora infestans is a microorganism commonly known for causing late blight, a disease notorious for decimating tomato and potato crops. Infamous for prompting massive famines in nineteenth century Britain, late blight is a frightening disease among growers. Treated worldwide with a plethora of fungicides, the attempt to eradicate P. infestans costs the global agriculture industry hundreds of millions of dollars annually.

Disturbing news have been coming in from Europe, where three new P. infestans sub-species have been discovered. These three newcomers were found in different parts of the continent - originating from the Netherlands and already spreading to Belgium, France, Germany, Poland, Denmark, Sweden and Norway. These new genotypes have been found to be resistant or insensitive to fluazinam, a commonly used fungicide.

The spread of these new species may already be felt, as last month, a late blight outbreak had been announced in UK tomato crops. This outbreak was reported as potentially being the discovery of a new strain, as crops were infected much earlier in the season than usual, in much younger plants. This has alarmed the AHDB (UK's Agriculture and Horticulture Development Board) and prompted SCEPTREplus, the AHDB's crop protection program, to conduct a trial to identify new potential options to control the disease.

Europe is not alone in this, as late blight look-alikes have also been spotted in tomato and potato crops in North Carolina. The North American crops are infected by Phytophthora nicotianae, an oomycete (fungus-like organism) of the same genus. Though not a new occurrence, growers in the southeast United States have been battling with the disease on a larger scale than usual, due to the season's relatively high precipitation levels.

With fungicides continually failing and new species popping up with higher resistance levels, it may be time to consider a different approach. Pests such as P. infestans may never be eradicated, but their outbursts may well be managed, at a lower cost than the current form of battle, using completely organic means.

Gracie Emeny, AHDB Knowledge Exchange Manager: "Conditions to avoid for disease development are a combination of 10-20˚C and high relative humidity. It’s important to prevent the development of standing water and surface wetness, and to remove all infected plant material from the glasshouse."

Humidity is a fairly new factor taken into consideration in greenhouse climate control, though technology has come a long way in a short period of time, with dehumidifiers now being designed specifically for agricultural uses.

DryGair, an Israeli-German owned company, along with Volcani Center - ARO (Israel’s Agricultural Research Organization), develops dehumidification systems specifically for greenhouse environments. Accompanied by growing amounts of research finding dehumidification to be a major factor for preventative pest control, such as the blight-causing P. infestans, and IPM (integrated pest management) growing as a real-world approach, DryGair's systems are on the verge of being a green-household item.