Blossom-End Rot Of Tomatoes Can Be Prevented

"Blossom-end rot of tomatoes and other vegetables is a problem that occurs from time to time.  The cause of blossom-end rot is a calcium deficiency in the fruit," according to Sherri Sanders, County Extension Agent Agriculture.


This deficiency may be due to several factors including lack of calcium in the soil, low moisture levels and root pruning.  Anything that interferes with calcium uptake by the root system of the plant can cause blossom-end rot.


Symptoms of blossom end rot are light tan lesions turning to dark brown sunken areas, usually at the end of the fruit.  Some lesions may occur on the side of the fruit.  The lesions are usually large and become more sunken and leathery accompanied by dry rot.  A black mold may grow on the surface of the lesion.


Several steps can be taken to prevent or control blossom end rot.  Soils should be limed to a pH of 6 to 7.  Timely irrigation to provide a constant moisture supply goes hand in hand with the lime, which provides calcium to the plant.


Stopping blossom-end rot once it has started is more difficult than preventing it.  If the problem is lack of moisture, this can be corrected by simply irrigating.  If the problem is a low pH or lack of calcium in the soil, the problem may be more difficult to control.  Because calcium is immobile in the plant, calcium sprays may not be effective.  Applications of calcium materials to the soil (either as a side-dressing or through drip irrigation tubing) would probably work better.  Materials to use would include calcium chloride or calcium nitrate.


The University of Arkansas System, Division of Agriculture is an equal opportunity/equal access/affirmative action institution.  For more information regarding this or similar subjects please contact your local county Cooperative Extension Service.  For more information you can contact your local county extension service, you can also follow Sherri Sanders on Facebook @UAEX.WhiteCountyAgriculture.