A Longer Strawberry Season in Canada Would Require More Fungicide Sprays

Anthracnose fruit rot

Anthracnose fruit rot

Ripening strawberries are very susceptible to anthracnose. The pathogen spreads rapidly through fruiting fields during rainy, warm harvest seasons and can quickly destroy a crop. Light-brown water-soaked spots form on ripening fruit and rapidly develop into firm round lesions followed by the eruption of pink spore masses in a slimy sticky matrix which are dispersed by splashing or wind-driven rain.

“In Canada, strawberry is cultivated mainly in Quebec, Ontario, British Columbia and the Atlantic provinces. Ontario ranks as the second highest strawberry producer (30%) in the country, with a farm-gate value of Cdn$ 20.8 million. Most of the fruit produced in Canada are from June-bearing cultivars, with a season that usually spans 5-6 weeks in June and July. In the off-season, large quantities of strawberries are imported, which were five times higher in 2011 than in 2003. The Canadian strawberry industry has given high priority to cultivation of day-neutral strawberry to become more competitive with the import market and increase the availability of fresh Canadian-grown strawberries to 4-5 months.

Anthracnose fruit rot (AFR), caused by Colletotrichum acutatum Simmonds, is one of the major diseases affecting yield in Ontario and other provinces. Pre- and post-harvest fruit rots caused by the fungus reduce marketable yields and the marketability of fruit, respectively. Long wet periods and warm temperatures (20-25 °C) during flowering and fruit development are favourable conditions for development of anthracnose fruit rot.

With the increase in production of day-neutral cultivars in Canada, attention should be given to the differences in cultivation practices from June-bearing cultivars. Since day-neutral strawberry have a longer cycle of fruit production, the risk of diseases and pests is also higher and thus different management strategies are required.

Since the day-neutral cultivars can be grown for a long season (4-5 months), numerous sprays (8-10) of fungicides are required to control diseases.”

Authors: Burlakoti, R. R., et al.
Affiliation: Weather Innovations Consulting LP.
Title: Evaluation of epidemics and weather-based fungicide application programmes in controlling anthracnose fruit rot of day-neutral strawberry in outdoor field and protected cultivation systems.
Source: Canadian Journal of Plant Pathology. 2014. 36[1]:64-72.


Fungicides Result in Mangoes Suitable for Export

Mango - Anthracnose

Mango – Anthracnose

Commonly known as the “King of Fruits,” the mango is the most important fruit of Asia. It is grown throughout the tropics and subtropics. Until recently, mango fruit was considered an exotic, specialty item in import markets such as the U.S. and Europe. Today a million tons of mangoes are exported. Among the diseases of mango, anthracnose is the most prevalent in humid growing regions. The incidence of this disease can reach almost 100% in fruit produced under wet or very humid conditions.

“Diseases are primary constraints to production in virtually all areas where mango is grown. … In humid regions, anthracnose is most destructive. … Pesticides are used in most commercial production situations, especially where anthracnose [is] important.”

“…irregular, dark brown to black lesions develop that are somewhat depressed and can crack the fruit surface. Under humid conditions, large areas may be involved and orange to pinkish masses of conidia are formed on the decaying surface. … Lesions on fruit are initially superficial, and penetrate deeper than 5 mm into the flesh only late in development. Anthracnose is caused by three closely related fungi. … Although some mango cultivars are moderately tolerant, none are sufficiently resistant to be produced without fungicides in humid areas.”

“In general, mango production currently has a heavy dependence on chemical disease control measures, especially where disease-conducive environments exist and when export quality fruit are desired.”

Author: R.C. Ploetz
University of Florida Tropical Research and Education Center, Homestead, FL
Title: The major diseases of mango: strategies and potential for sustainable management.
Publication: Proceedings of the VIIth International Symposium on Mango. 2004. 137-150.

Japan’s Most Popular Green Tea Variety Depends on Fungicides

In the 1970s, a new high-yielding green tea variety – Yabukita – was introduced in Japan and has been wildly popular because of quality attributes that Japanese tea drinkers favor, including the characteristic “umami” savory taste. This one-cultivar industry led to prevalent and frequent outbreaks of tea plant diseases which has resulted in a dependence on regular fungicide applications.

“Tea is one of the most important cash crops in the warm southwest areas of Japan. The green tea cultivar ‘Yabukita’ has been cultivated since the 1970s and grown in about 75% of all tea fields in Japan. Using a monoculture cultivation system, new Yabukita tea shoots can be harvested synchronously, producing green tea of consistent quality. However, this system has resulted in severe pest problems such as outbreaks of tea anthracnose … and tea gray blight … Therefore, repeated spraying of fungicides is needed to protect tea plants against both the diseases for each tea crop.”

Authors: K. Yoshida, A. Ogino, K. Yamada and R. Sonoda
Affiliation: National Institute of Vegetable and Tea Science
Title: Induction of disease resistance in tea (Camellia sinensis L.) by plant activators.
Publication: Japan Agricultural Research Quarterly. 44(4):391-398.