Changing Smell of Plants Announces Pathogen Attack

Tomato plants under attack from the Botrytis fungus give off an aromatic substance that can be measured in greenhouses, scientists at the Wageningen University in the Netherlands discovered. Botrytis or gray mold is an important disease in global tomato cultivation, normally controlled using chemical pesticides.

Through a series of tests, Roel Jansen and colleagues showed that tomato plants infected by Botrytis fungus give off more methyl salicylate into the greenhouse air. Often the plants emit sufficient amounts of this hormone substance for it to be measurable in the air. The researchers believe that detection of volatile compounds in the greenhouse air presents a new way of preventing and managing disease and plague problems in greenhouse horticulture. "If you can identify a plague in a greenhouse on time there will be even less need for pesticides," Jansen says. "The trend in greenhouse horticulture is for fewer but larger greenhouses. An outbreak of a disease or plague therefore forms an even greater threat as it can easily spread throughout the entire greenhouse."

Read more at http://www.wur.nl/UK/newsagenda/news/smell191009.htm