APE 311 PROTECTED CULTIVATION AND SECONDARY AGRICULTURE 1+1
Lecture No. 01
Introduction to protected cultivation – need, advantages and limitations and present status
– protected cultivation for horticultural crops
1.1 Introduction
India has a wide range of diverse agro-climatic conditions, but vegetable cultivation
practices have generally been restricted to regional and seasonal needs. Although the production
of vegetables has increased to a level of 93.9 million tonnes from an area of 6.3 million hectares
(2000-01), but still the technology used and practices followed are predominantly traditional,
resulting in low productivity and inconsistent quality and quantity of produce supplies to various
markets in the country.
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. 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. 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.
In many countries like European countries, USA, Japan, China, Israel, Morocco, Turkey,
etc. where climate prevents and reduces the choices for year round out door production,
vegetables are being produced in protected environments. Greenhouse being 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.
India has entered in to the era of greenhouse vegetable cultivation more recently and the
total are under protected vegetable production is not more than 10,000 hectares. India being a
vast country with diverse and extreme agro-climatic conditions, 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.
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.
Under open field cultivation, while the other factors could be taken care of, it is not
possible to effect control on the environment around the plant. The plant's environment can be
specified by five basic factors, namely, light, temperature, humidity, carbon dioxide and
, APE 311 PROTECTED CULTIVATION AND SECONDARY AGRICULTURE 1+1
nutrients. 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. 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.
Protected cultivation offers several advantages to produce vegetables and flowers of high
quality and yields, thus using the land and other resources more efficiently. This becomes
relevant to growers in India who have small land holding, say less than one hectare. They would
be interested in a technology, which helps them to produce more crops each year from their land,
particularly during off-season when prices are higher. However, growing vegetables under
protected conditions requires comparatively high input cost and good management practices,
which have direct bearing on the economic viability of the production system. Even if the
protective structures are cost effective, proper planning, management and attention to details are
needed to achieve maximum benefits. Growing vegetables and flowers under location-specific
suitable structures may accrue substantial benefits even to small growers.
1.2 Definition
Protected cultivation is the modification of the natural environment to achieve optimum
plant growth. Modification can be made to both the aerial and root environment to increase crops
yields, extends the growing season and permit growth during periods of the year not commonly
used to grow field crops.
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.
1.3 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.
1.3.1 Status of greenhouses for horticultural crop production in different countries
Limited areas around the world are endowed with favourable environment for year round
outdoor crop production. In most cases, production is limited to a given period of the year when
irradiance and temperature are conducive for optimum plant growth. In outdoor conditions, plant
growth and yields are highly variable as they strongly depend upon the prevailing environment.
, APE 311 PROTECTED CULTIVATION AND SECONDARY AGRICULTURE 1+1
So in order to minimize this variability, growing of crops adversely affected by weather
fluctuation encouraged under greenhouse systems.
Greenhouses are the permanent protected structures being used for horticultural crop
production in several countries of the world. These may be of different type according to their
use and need like climate controlled greenhouse or naturally ventilated greenhouse, but all these
are covered with plastic on the top and insect proof net on all sides. Greenhouses are used to
provide the maximum control over varied environmental conditions surrounding the plant. The
greenhouse structure modifies the environmental conditions and allows the crop production in
the regions where outdoor production would not be possible. Greenhouse production also
involves growing of specially or niche-marketed crops like that of tomato, cucumber, etc.
There has been tremendous increase in area under greenhouse cultivation of horticultural
crops in most countries around the last two decades. China, Japan, Spain and Italy are ahead in
the production of horticultural crops in greenhouse. In India, the area under greenhouse
cultivation of horticultural crops is not more than 1,000 hectares and it mainly confined to
Maharasta and Karnataka. There is lot of potential increasing the area under low cost greenhouse
manifold in peri-urban areas of the country for production of high value vegetables during off-
season to take benefit of the high price of the produce.
1.3.1.1 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. In most of the countries, the greenhouses are made of plastic
except the glass houses in Netherlands. Glasshouse and rigid-plastic houses are longer life
structures, and are therefore mostly located in cold regions, where these structures can be used
for crop production throughout the year. Asian continent has maximum area under greenhouses
and China leads amongst countries followed by Italy, Spain and Japan.
1.3.1.2 Semi-climate controlled greenhouses: In this kind of 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.
, APE 311 PROTECTED CULTIVATION AND SECONDARY AGRICULTURE 1+1
1.3.1.3 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.
1.3.2 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.
Although the use of these protected structures started in West and North European
countries and Japan, but, presently, China has the largest area under plastic low tunnels followed
by Japan and other European countries. In India, although the area under plastic low tunnel
cultivation of horticultural crops is not more than 1,000 hectares yet these are highly suitable and
profitable for off-season growing of vegetables in peri-urban areas of Northern plains, cold
dessert areas as well as other areas of hill states like Himachal Pradesh and Uttaranchal. The
production technology for off-season cultivation of cucurbits under plastic low tunnels has
already been standardized by Indo-Israel Project at Indian Agricultural Research Institute, New
Delhi for commercial cultivation of vegetable crops during off-season. Moreover, with the
introduction and availability of biodegradable plastics for making low tunnels, there may be a
big breakthrough in this technology in India as it will be more eco-friendly and environmentally
sustainable.
1.3.3 Status of floating mulch of floating row cover
Floating mulches are also the temporary and low cost protected structures made without
any mechanical support of wire hoops, which mainly provide protection against adverse
temperature conditions for out of season cultivation of several horticultural crops, especially
Lecture No. 01
Introduction to protected cultivation – need, advantages and limitations and present status
– protected cultivation for horticultural crops
1.1 Introduction
India has a wide range of diverse agro-climatic conditions, but vegetable cultivation
practices have generally been restricted to regional and seasonal needs. Although the production
of vegetables has increased to a level of 93.9 million tonnes from an area of 6.3 million hectares
(2000-01), but still the technology used and practices followed are predominantly traditional,
resulting in low productivity and inconsistent quality and quantity of produce supplies to various
markets in the country.
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. 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. 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.
In many countries like European countries, USA, Japan, China, Israel, Morocco, Turkey,
etc. where climate prevents and reduces the choices for year round out door production,
vegetables are being produced in protected environments. Greenhouse being 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.
India has entered in to the era of greenhouse vegetable cultivation more recently and the
total are under protected vegetable production is not more than 10,000 hectares. India being a
vast country with diverse and extreme agro-climatic conditions, 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.
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.
Under open field cultivation, while the other factors could be taken care of, it is not
possible to effect control on the environment around the plant. The plant's environment can be
specified by five basic factors, namely, light, temperature, humidity, carbon dioxide and
, APE 311 PROTECTED CULTIVATION AND SECONDARY AGRICULTURE 1+1
nutrients. 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. 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.
Protected cultivation offers several advantages to produce vegetables and flowers of high
quality and yields, thus using the land and other resources more efficiently. This becomes
relevant to growers in India who have small land holding, say less than one hectare. They would
be interested in a technology, which helps them to produce more crops each year from their land,
particularly during off-season when prices are higher. However, growing vegetables under
protected conditions requires comparatively high input cost and good management practices,
which have direct bearing on the economic viability of the production system. Even if the
protective structures are cost effective, proper planning, management and attention to details are
needed to achieve maximum benefits. Growing vegetables and flowers under location-specific
suitable structures may accrue substantial benefits even to small growers.
1.2 Definition
Protected cultivation is the modification of the natural environment to achieve optimum
plant growth. Modification can be made to both the aerial and root environment to increase crops
yields, extends the growing season and permit growth during periods of the year not commonly
used to grow field crops.
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.
1.3 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.
1.3.1 Status of greenhouses for horticultural crop production in different countries
Limited areas around the world are endowed with favourable environment for year round
outdoor crop production. In most cases, production is limited to a given period of the year when
irradiance and temperature are conducive for optimum plant growth. In outdoor conditions, plant
growth and yields are highly variable as they strongly depend upon the prevailing environment.
, APE 311 PROTECTED CULTIVATION AND SECONDARY AGRICULTURE 1+1
So in order to minimize this variability, growing of crops adversely affected by weather
fluctuation encouraged under greenhouse systems.
Greenhouses are the permanent protected structures being used for horticultural crop
production in several countries of the world. These may be of different type according to their
use and need like climate controlled greenhouse or naturally ventilated greenhouse, but all these
are covered with plastic on the top and insect proof net on all sides. Greenhouses are used to
provide the maximum control over varied environmental conditions surrounding the plant. The
greenhouse structure modifies the environmental conditions and allows the crop production in
the regions where outdoor production would not be possible. Greenhouse production also
involves growing of specially or niche-marketed crops like that of tomato, cucumber, etc.
There has been tremendous increase in area under greenhouse cultivation of horticultural
crops in most countries around the last two decades. China, Japan, Spain and Italy are ahead in
the production of horticultural crops in greenhouse. In India, the area under greenhouse
cultivation of horticultural crops is not more than 1,000 hectares and it mainly confined to
Maharasta and Karnataka. There is lot of potential increasing the area under low cost greenhouse
manifold in peri-urban areas of the country for production of high value vegetables during off-
season to take benefit of the high price of the produce.
1.3.1.1 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. In most of the countries, the greenhouses are made of plastic
except the glass houses in Netherlands. Glasshouse and rigid-plastic houses are longer life
structures, and are therefore mostly located in cold regions, where these structures can be used
for crop production throughout the year. Asian continent has maximum area under greenhouses
and China leads amongst countries followed by Italy, Spain and Japan.
1.3.1.2 Semi-climate controlled greenhouses: In this kind of 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.
, APE 311 PROTECTED CULTIVATION AND SECONDARY AGRICULTURE 1+1
1.3.1.3 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.
1.3.2 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.
Although the use of these protected structures started in West and North European
countries and Japan, but, presently, China has the largest area under plastic low tunnels followed
by Japan and other European countries. In India, although the area under plastic low tunnel
cultivation of horticultural crops is not more than 1,000 hectares yet these are highly suitable and
profitable for off-season growing of vegetables in peri-urban areas of Northern plains, cold
dessert areas as well as other areas of hill states like Himachal Pradesh and Uttaranchal. The
production technology for off-season cultivation of cucurbits under plastic low tunnels has
already been standardized by Indo-Israel Project at Indian Agricultural Research Institute, New
Delhi for commercial cultivation of vegetable crops during off-season. Moreover, with the
introduction and availability of biodegradable plastics for making low tunnels, there may be a
big breakthrough in this technology in India as it will be more eco-friendly and environmentally
sustainable.
1.3.3 Status of floating mulch of floating row cover
Floating mulches are also the temporary and low cost protected structures made without
any mechanical support of wire hoops, which mainly provide protection against adverse
temperature conditions for out of season cultivation of several horticultural crops, especially
