A major pathogen in roses, the mould Botrytis cinerea, can be easily kept at bay with a dash of chlorine. Wageningen researchers discovered this by chance.
Control substance turns out to be answer
Things can be much simpler, American and Wageningen researchers reveal this month in the journal Postharvest Biology and Technology. Ernst Woltering and American colleagues from UC Davis compared commercial substances for getting rid of botrytis in the laboratory. During the test, the researchers used a household chlorine solution as the control substance. To their surprise, chlorine worked better than the other substances. A litre of water with a small dash of Glorix (one or two millilitres of household detergent) is all it takes, says Woltering. The chlorine kills the spores of the mould. 'If the plant is already infected by the mould, chlorine is useless.'
Woltering has in the meantime tested the use of household chlorine in batches of roses transported in containers on ships. Its use has resulted in fifty to seventy percent less damage by botrytis. Moreover, the damage in affected roses is less severe, Woltering concludes from this study.
The researchers have discovered the positive effects of household chlorine already two years ago, but wanted first to find out if they can apply for a patent for their discovery. 'But the answer is so terribly simple that it cannot be patented', says Woltering. 'Anyone can buy chlorine solution. The discovery cannot be protected. We have therefore decided to publish the outcome.'