Tropical and subtropical vegetables (2+1)

Physiological disorders/constraints

Physiological disorders/constraints
Blossom end rot:
A disorder of sweet pepper where water soaked spots first appears on the blossom end of fruit. The spots soon become light brown and papery as the lesions dry out. The causes and control measures are similar to tomato. i.e. for controlling the disorder we should follow judicious and timely irrigation and the crop should be grown in the soil having good water holding capacity.
Sun scald:
A disorder of sweet pepper, it occurs when the fruits are exposed to scorching sunlight. This disorder arises as a soft, light coloured area in fruit that becomes slightly wrinkled. Plants having enough foliage are less prone to this disorder.
Skin cracking:
A disorder of sweet pepper where cracking occurs around the shoulder of fruits. It is often associated with fluctuations in temperature and humidity. High day temperature and average RH increases the incidence of cracking.
Flower and fruit drop:
It is one of the major constraints in chilli cultivation.
Flower and fruit drop may occur due to
(1) Low humidity and high temperature condition which result in excessive transpiration and water deficit in the plant and cause abscission of buds, flowers and small fruits
(2) decreasing light intensity
(3) Short day and high temperature and
(4) High temperature during early flowering stages.

Control
1. Irrigation at flowering and fruit set stage helps in reducing blossom end rot and fruit drop.
2. Foliar application of 50 ppm NAA at full bloom set stage effectively controls the drop.
3. Foliar application of 20 ppm NAA at first flower opening followed by two sprays at an interval of 30 days increases fruit set.
4. Application of Triacontanol (vipul 1ml/ 2 litre of water) also markedly reduces flowers and fruit drop.