Diseases and Management of Crops under Protected Cultivation

(Diseases and Management of Crops under Protected Cultivation)
Elephant Foot
Blossom End Rot (BER)
• BER can be caused by reduced absorption and translocation of Ca into the fruit.
• Ca deficiency can be due to low Ca in media, excessive salinity or moisture fluctuations in
the media
Management
• Avoid the conditions of moisture stress or conditions of reduced transpiration.
• Weekly foliar applications of calcium nitrate can have a significant impact on reducing the
amount of BER
Sunscald
• Soft, tan coloured sunken lesions develop fruit that are exposed to direct sunlight.
Management
• It is important to adjust pruning practices to ensure that all fruit are shaded from direct
sunlight.
• Apply shad net to the greenhouse during the summer months will also help reduce the
incidence of sunscald.
• Fruit temperatures over 35°C should be avoided.
Fruit Cracking
• Characterized by the appearance of very fine, superficial cracks on the surface of the
capsicum fruit.
• Ruptures on the cuticle at blossom end is Radial cracking or all over the fruit surface is
Russeting.
• Fruit cracks may be due to
o high relative humidity (over 85%).
o Sudden changes in weather conditions (from hot sunny weather to cool cloudy
weather or vise versa).
o thick walled fruits(>8mm).
Management
• Avoid high humidity
• Use thin walled fruit varieties
Fruit Splitting
The development of large cracks in the fruit is a direct response to high root pressure.
Factors that contribute to the development of high root pressure directly impact fruit
splitting.
Management
Adjust the timing of the last watering in the day so as not to water too late.
Eliminate any night watering cycles.
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