Blossom End Rot
World Vegetable Center
This is a non-infectious disease that is associated with
environmental conditions. It can affect all fruits but often
is most often found on the first pepper fruit cluster.
At the earliest stage, water-soaked, tan patches appear
near the blossom end of fruits. These patches develop
into sunken, dry patches that are tan to black in color.
An area up to half the fruit may be affected. Sometimes,
the dead tissue may be invaded by secondary
organisms, which causes a soft fruit rot. Internal
blackening can also develop. The affected fruit ripens
more quickly than unaffected fruit.
Conditions for Disease Development
The disorder develops when a rapidly enlarging fruit does
not receive enough calcium for its cellular growth. This
most often occurs when there are fluctuations in the
water supply during rapid plant growth, particularly if
long periods of dry weather are followed by excess
availability of water.
Other factors that predispose a plant to blossom
end rot are high humidity, damage to the roots, use of
ammonium nitrate as nitrogen source, low potassium
and calcium levels, high levels of magnesium and
nitrogen in the soil, and high soil salinity.
Symptoms begin as a water-soaked brown spot on the blossom end (left),
later developing into a black leathery rot
How to Identify Blossom End Rot
Written by Ray Cerkauskas, Visiting Scientist from Agriculture and Agri-Food Canada. Edited by Tom Kalb. Photos by J.C. Watterson,
E.L. Shannon and D.F. Ritchie. Published by AVRDC – The World Vegetable Center; P.O. Box 42, Shanhua; Taiwan 741; ROC
tel: (886-6) 583-7801; fax: (886-6) 583-0009; email: email@example.com; www: www.avrdc.org
AVRDC Publication 04-582
For more information on the production of
pepper and other vegetables, go to
Ensure steady plant growth and a constant soil moisture
level through careful irrigation. Provide balanced
fertilization and avoid root damage of young plants. Soil