Diseases and Management of Crops under Protected Cultivation

(Diseases and Management of Crops under Protected Cultivation)
radiation" in the range of 400-700 Nm wave length. The sunlight admitted to the protected
environment is absorbed by the crops, floor, and other objects. These objects in turn emit long
wave thermal radiation in the infra red region for which the glazing material has lower
transparency. As a result the solar energy remains trapped in the protected environment, thus
raising its temperature. This phenomenon is called the "Green house Effect". This condition of
natural rise in green house air temperature is utilized in the cold regions to grow crops
successfully. However, during the summer season due to the above stated phenomenon
ventilation and cooling is required to maintain the temperature inside the structure well below
35°C. The ventilation system can be natural or a forced one. In the forced system fans are used
which draw out 7- 9m 3 of air/sec/ unit of power consumed and are able to provide 2 air changes /
minute.
2. Why Protected Cultivation
The vegetables / any other produce harvested from the protected cultivation have better
quality in terms of the fruit size, per fruit weight, TSS, colour, texture and other quality
parameters.
The productivity of the crop under protected cultivation increases manifold (2-10 times) as
compared to conventional system.
Off-season cultivation of the vegetables/other crops is the most important aspect of
protected cultivation. The winter season vegetable crops such as cauliflower, coriander,
spinach etc can be grown during rainy season. Similarly, summer season vegetable crops
are successfully grown during winter and the winter season leafy vegetable can be grown
during summer.
Under protected environment the incidence of insect and disease are minimized due to its
isolation from open field. Use of micro irrigation and off-season cultivation also minimizes
the disease and insect incidence. Less infestation of insects and disease offer reduced use
of pesticides.
The protected cultivation offers efficient use of two most precious resources land and
water. Other inputs such as fertilizers, chemicals and labour are also efficiently utilized
under such environment.
The year round cultivation of single / multiple crops with high quality produce and high
productivity. The off-season cultivation of vegetable offers better market price and
increased employment generation round year for the small and marginal farmers in hills
and peri-urban areas.
3. Irrigation Techniques for Protected (Green House/Shade Net House and Walking /Low
Tunnel) Cultivation
It is very difficult to obtain full benefit from protected cultivation without microirrigation and
fertigation. An efficient irrigation system preferably microirrigation combined with fertigation system
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