Kim Lewers, USDA-Agricultural Research Service Kim Lewers, USDA-Agricultural Research Service Beltsville, MarylandBeltsville, Maryland

•Plugs are made from end of June to 4 July.•Plugs are planted in the field the first half of August.•The field is fertigated with ~12lbs/A of nitrogen after one week, every week to 3rd week of September, to a total of ~75 lbs/A.•The beds are covered with straw mid-December to mid- March.

•Frost protection is a combination of misters at 34F and Rainbirds at 32.1F.•The field is fertigated with ~5lbs/A of nitrogen per week in April, to between 20-30 lbs/A.•Plots are harvested twice weekly from mid-May through mid-June. •Rotation is ‘Essex’ rape - strawberry – corn or sudex – soybeans, with rye-vetch winter covers.

Influence of Nitrogen, Phosphorus, and Potassium on the Severity of Strawberry Anthracnose Crown Rot

B.J. Smith United States Department of Agriculture, Agricultural Research Service Southern Horticultural Laboratory, Small Fruit Research Unit Poplarville, MS 39470 USA

Seven (7) nitrogen sources at three (3) rates:•Higher N rates led to more anthracnose.•Among plants getting higher N rates, those treated with Ca(NO3)2 were the most disease tolerant. •Plants treated with nitrate nitrogen sources, including NH4NO3, had less severe anthracnose symptoms than plants receiving nitrogen from other ammonium sources.

Take-home: Nitrate forms mean less anthracnose than ammonium forms.

‘‘Earliglow’Earliglow’

‘‘Allstar’Allstar’

‘‘Ovation’Ovation’

B1033B1033

Hand-outs to take home…

Post-harvest rot % is calculated from the number of total berries that are rotted after two weeks at storage in clamshells at 41F.

Field rot % is calculated by harvesting the good fruit and rotten fruit into two buckets and weighing them separately.

The average berry size for each harvest was recorded. “Average berry size” is the average of all those averages. “Large berry size” is the largest of those averages.

USDA-ARS Beltsville strawberry breeding yield gainUSDA-ARS Beltsville strawberry breeding yield gain

John EnnsJohn Enns George MeyersGeorge Meyers

Thank you! Want to visit?Thank you! Want to visit?Kim.Lewers@ ARS.USDA.govKim.Lewers@ ARS.USDA.gov

Office: 301-504-6768Office: 301-504-6768Cell: 240-463-5654Cell: 240-463-5654