Phytophthora Fragariae - Importance

Importance

P. fragariae was first observed in 1921 in Scotland. The actual infectious agent was not identified until 1940 by C.J. Hickman. The disease was not found in the United States until 1935 when it was reported in eastern Illinois. Once discovered, a survey was done to identify other states that had the disease. It was found in Maryland, New Jersey, New York, and Michigan. Some farmers claimed that they had been observing the disease as early as 1925, so it is thought this disease could have developed at the same time as the Scottish outbreak. The disease is wide spread and in many cases causes devastation to strawberry plants and strawberry production. Little about exact numbers has been found and may not have been recorded. Some information suggests that after a severe outbreak farmers could see yields as low as one ton per hectare. On average, one uninfected hectare of strawberry plants would produce about nine tons of strawberries. One estimate reported that farmers in Nova Scotia lost 78% of their strawberries in one season. They lost almost 1500 Canadian dollars per hectare. The disease is extremely devastating to raspberries as well. Raspberry plantations are huge capital investments that can take 10 to 15 years of production to earn back the initial investment. This disease can wipe out entire plantations in only a few years, effectively ruining a starting raspberry farm. P. fragariae is important wherever strawberries and raspberries are grown and where conditions are ideal. The countries it effects most are the U.S., China, Belgium, France, Germany, Italy, Netherlands, Russia, Switzerland, Norway and the UK, but not Finland.