2. Need and Scope
• India has a wide range of diverse agro-climatic
conditions, but vegetable cultivation practices
have generally been restricted to regional and
seasonal needs.
• In several parts of the country, especially in
northern plains, the soils are highly fertile but
extremes of temperature, ranging from 0-48°C
during the year do not allow year round
outdoor vegetable cultivation.
3. • Similarly, in several parts of the country biotic
stresses mainly during rainy and post rainy
season do not allow successful production of
vegetables like tomato, chillies, okra, sweet
peppers, etc. in open fields.
• As a result most of these vegetables are
severely damaged by the incidence of viruses.
4. • In upper reaches of Himalayas, cool dessert condition prevail
where the temperature is extremely low (-5 to -30°C) during
winter season and most of the region remain cut off from rest
of the country from November to March due to very heavy
snowfall.
• Therefore, it is very difficult to grow vegetables in such a
climate.
• Production of vegetables and flowers is significantly
influenced by the seasonality and weather conditions. The
extents of abundance and deficiency in production cause
considerable fluctuations in the prices and quality of
vegetables and flowers
5. Protected cultivation
• the most efficient means to overcome climatic
diversity, greenhouse vegetable production
makes the use of recent advances in
technology to control the environment for
maximizing crop productivity per unit area
and increasing the quality of vegetable
produce.
6. • the protected vegetable cultivation technology can be
utilized for year round and off – season production of
high value, low volume vegetable crops, production of
virus free high quality seedlings, quality hybrid seed
production and as a tool for disease resistance
breeding programmes.
• The main purpose of protected cultivation is to create a
favourable environment for the sustained growth of
plant so as to realize its maximum potential even in
adverse climatic conditions.
7. Types of structures
• Greenhouses, rain shelters, plastic tunnels,
mulches, insect - proof net houses, shade
nets, etc. are used as protective structures and
means depending on the requirements and
cost effectiveness.
• Besides modifying the plant's environment,
these protective structures provide protection
against wind, rain and insects.
8. Definition
• Protected cultivation is the modification of the
natural environment to achieve optimum
plant growth.
• Protected cultivation may also indicate
comprehensive system of controlled
environmental agriculture (CEA) in which all
aspects of the natural environment are
modified for maximum plant growth and
economic return.
9. Present Scenario of Protected
Cultivation
• In general, protected structures are used to overcome low
temperatures in temperate regions or high temperature in
the countries having tropical climate.
• The need of protected structure directly depends upon the
climate of the region, growing season and kind of crop to
be grown.
• Protected cultivation technologies are being utilized all over
the world but the level and extent of their use may be
different among different countries.
• Therefore, it is necessary to know the status of protected
structures, the crops being grown there the world over and
the future prospects of protected cultivation of
horticultural crops in India.
10. High-tech or climate controlled
greenhouse
• This type of greenhouse is constructed to achieve higher degree
of climate control to enhance the cultivation period of crops.
• Evaporative cooling and heaters are used to maintain required
temperature inside greenhouse spaces as and when needed.
The climate is usually accomplished through automatic system.
• Such type of greenhouses is used for growing high value
blemish free crops of tomato, cherry tomato, sweet pepper and
cucumber for long period. These greenhouses are mainly being
used in several European countries, Morocco, Israel, USA and
Japan.
• These greenhouses are mostly used for long duration cultivation
of tomato and sweet pepper over a longer period of time
11. Semi-climate controlled greenhouses
• the structural frame is made of galvanized iron pipes,
like the climate controlled greenhouse
• but only exhaust fans with evaporative cooling pads are
provided to maintain a favourable temperature and
humidity during summer.
• These types of greenhouses are suitable for vegetable
cultivation during mild winter and mild summer only.
• The basic cost of erection of these greenhouses is half
to that of climate controlled greenhouses and are
mainly being used in Turkey, Spain, USA, Morocco,
Israel and Japan.
12. Naturally ventilated or low cost
greenhouses
• These are simple construction greenhouses with low initial
investment. The frame may be of galvanized iron pipes, wooden logs
or steel pipes but no heating and cooling systems are provided for the
structure.
• The top of the greenhouses is covered with plastic but the side walls
have insect proof nets from ground to a height of 1.5 to 2 m (5 to 6
feet) with or without manually rollable plastic cover.
• The initial cost of these greenhouses is less than half to that of semi-
climate controlled greenhouses.
• These are mainly used for production of cucumber, muskmelon,
tomato etc.
• These are being used extensively in China where the area during the
last two decade has increased rapidly. Other countries using such
greenhouses are Japan, Israel, Turkey and Morocco, etc.
13. Status of plastic low tunnels
• Plastic low tunnels or row covers are simple and low cost structures for
off-season production of vegetables crops in open field. These are flexible
transparent coverings that are installed over single or multiple rows of
vegetables crops during winter season to enhance plant growth as the
micro-climate around the plants gets congenial warmth.
• The soil temperature is also raised and the plants are also protected from
hails, cold wind injury, frost etc. plastic low tunnels or row covers
originated during the 16th and 17th centuries with the use of jars, cloches
and cold frames placed over the plants during the cold period. Low
tunnels can be supported over the plants using hoops of wire.
• A transparent or white plastic is stretched over the hoops and the sides are
secured by placing it in the soil. The plastic of the tunnel can be vented
during the cropping season as the temperatures increase within the
tunnel environment. Since construction and dismantling of these facilities
occur frequently, therefore, statistical data are less reliable than from
permanent structures, such as greenhouses, glasshouses, walk-in-tunnels,
etc.
14. Prospects and Strategies
• Cost-effective design of greenhouses and their manufacturing based on
location specific need to be developed
• The package of practices including fertigation needs to be worked out for
different agroclimate situations.
• Pest and disease management is crucial in protected conditions which
provide a favourable condition for their proliferation.
• Intensive cultivation in greenhouses give rise to the growth and
development of numerous pathogens including nematodes. Effective and
eco-friendly control measures are to be evolved.
• Development of suitable varieties for protected cultivation requires an
immediate attention and efforts to reduce dependence on imported
seeds.
• Protected cultivation is labour intensive. Therefore suitable design of
tools, devices and equipment are required to reduce the cost of
cultivation and enhance timeliness of operations.
• A major concern is disposal of used plastics, therefore new generation
biodegradable polymers need to be developed.
15. Advantages of Protected Cultivation
• Vegetable crops can be grown under unfavourable agro-climatic
conditions.
• (ii) Certain vegetable crops can be grown round the year in a particular
place.
• (iii) Crop yields can be several times higher than those of under open
field conditions.
• (iv) Quality of produce is superior.
• (v) Higher input use efficiencies are achieved.
• (vi) Management of insects pests, diseases, weeds, etc. is easier under
protection.
• (vii) Agricultural income per unit area increases.
• (viii) It provides an excellent opportunity to produce vegetables for
export.
• (ix) Protected structures are ideally suited for production of genetically
engineered and
• micro-propagated vegetable varieties and hybrids.
16. Constraints of Protected Cultivation
• Very high basic cost and operational cost
• Irregular power supply
• Little work on designing structures for different locations
• Quality of cladding material quality and their non
availability
• Lack of technical knowhow
• Lack of indigenous technology (Zone/region)
• Lack of suitable varieties / hybrids for greenhouse
cultivation
• Exotic seeds are very costly
• Poor performance of indigenous varieties
