Submitted to: Crop Protection Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/8/2006
Publication Date: 8/1/2007
Citation: Wedge, D.E., Smith, B.J., Quebedeaux, J.P., Constantin, R.J. 2007. Fungicide Management Strategies for Control of Strawberry Fruit Rot Diseases in Louisiana and Mississippi. Crop Protection Journal. 26:1449-1458. Interpretive Summary: Fruit rot diseases of strawberry are serious problems for strawberry producers in many areas of the world and are particularly severe in the southeastern United States where disease is often enhanced by warm temperatures and frequent rains during the harvest season. Major fruit rot diseases include anthracnose (Colletotrichum spp.), Botrytis gray mold (Botrytis cinerea), leather rot (Phytophthora cactorum), and stem end rot (Gnomonia comari). Chemical control of these diseases can be difficult as several effective fungicides are no longer sold in the U.S. or have lost their registration for use on strawberries, and some of the pathogens have developed resistance to the more commonly used fungicides. Among the fungicides registered for use on strawberries, it is recommended that fungicides with different modes of action be applied alternately, as co-formulations, or as tank mixes to prolong their usefulness. Fungicides trials were conducted to determine the efficacy of fungicides with different modes of action for control of strawberry fruit rot diseases. Results indicate that there are a number of fungicides with a variety of modes of action available to strawberry growers in the U. S. that are effective in controlling the major fruit rot diseases. Strawberry growers should be advised to follow label recommendations of alternating and/or tank mixing fungicides from different fungicide groups to slow the development of fungicide resistant pathogen strains.
Technical Abstract: Sixteen different fungicide treatments were evaluated in five fungicide studies conducted at Hammond, LA and Poplarville, MS during the 2002, 2003 and 2005 fruiting seasons. Treatments were applied at 7-10 day intervals to the strawberry cultivars, Camarosa (LA), Chandler (MS), or Pelican (MS). Diseases occurring on berries at harvest were identified and counted. The most frequent fruit rots were anthracnose fruit rot (Colletotrichum spp.), stem end rot (Gnomonia comari), and Botrytis gray mold (Botrytis cinerea). Significant differences in total fruit rot due to fungicide treatment occurred in three of the five trials. Compared to berries from the untreated control treatment, berries from the pyraclostrobin + boscalid treatment had significantly less total fruit rots in three trials, and berries from the cyprodinil + fludioxonil, pyraclostrobin, azoxystrobin, fenhexamid + captan, and captan treatments had less total fruit rots in two trials. Compared to the untreated control treatment, less anthracnose fruit rot occurred on berries from the cyprodinil + fludioxonil and azoxystrobin treatments in two trials and from the