BASICS OF GREENHOUSE, TYPES OF GREENHOUSE, COMPONENTS OF GREENHOUSE, ENVIRONMENTAL FACTORS AND THEIR EFFECT ON PLANT GROWTH Greenhouse: It is a framed or inflated structures covered with transparent or translucent material large enough to grow crops under partial or fully controlled environmental conditions to get optimum growth and productivity. Principles of greenhouse: The greenhouse cultivation based upon the principle called as greenhouse effects. Greenhouse transmit the solar energy inside the structure. This energy absorbed by the crops and the objects inside the house releasing light of long wave length, finally this light does not emit out as the cladding material is non-transparent for these light. Finally the light gets trapped inside increasing the inside temperature. This rise in temperature in greenhouse is responsible for plant growth in cold climate. However during summer increase in temperature can be managed by ventilation and cooling system, as in this period temperature rose beyond the critical temperature.

1. ASPEE COLLEGE OF HORTICULTURE AND FORESTRY
NAVSARI AGRICULTURAL UNIVERSITY
NAVSARI – 396450
Submitted to
Dr. B. M. Tandel
Associate Professor
Department of Fruit Science
ASPEE College of Horticulture and Forestry
NAU, Navsari
Submitted by
3rd Sem. M.Sc. Horticulture
:Title:
BASICS OF GREENHOUSE, TYPES OF GREENHOUSE,
COMPONENTS OF GREENHOUSE, ENVIRONMENTAL FACTORS
AND THEIR EFFECT ON PLANT GROWTH
FSC 511
Protected fruit culture(2+1)

2. • It is a framed or inflated structures covered with transparent
or translucent material large enough to grow crops under
partial or fully controlled environmental conditions to get
optimum growth and productivity.
OR
• A greenhouse is a structure under a translucent covering
material which protects plants from wind, precipitations,
excessive radiation, temperature extremes, insects and
diseases. It is also of vital importance to create an ideal micro-
climate around the plants.
“Greenhouse Technology is the science of providing favourable
environment conditions to the plants”.
1

3. • The greenhouse cultivation based upon the principle called as greenhouse
effects.
• Greenhouse transmit the solar energy inside the structure. This energy
absorbed by the crops and the objects inside the house releasing light of long
wave length, finally this light does not emit out as the cladding material is
non-transparent for these light.
• Finally the light gets trapped inside increasing the inside temperature. This
rise in temperature in greenhouse is responsible for plant growth in cold
climate.
• However during summer increase in temperature can be managed by
ventilation and cooling system, as in this period temperature rose beyond the
critical temperature.
2

4. 3

5. Area under protected cultivation at global level
Country Area (ha)
China 2,760,000
Korea 57,444
Spain 52,170
Japan 49,049
Turkey 33,515
India 30,000
Italy 26,500
Mexico 11,759
Netherlands 10,370
France 9,620
USA 8,425
4

6. Leading States of India in Protected Cultivation
States Area (ha)
Maharashtra 15,000
Karnataka 10,000
Himachal Pradesh 5000
Gujarat 4720
Punjab 4000
Uttarakhand 3000
Tamil Nadu 2100
North-Eastern 2000
Other states:- Haryana, UP, Rajasthan, Jharakhand, J & K, Delhi,
West Bengal, Orissa, Bihar, MP
5

7. • Higher yield
• Better quality
• Early production
• Assured and early production
• Least pesticide residues
• Controlled pollination
• Vagaries of weather
• Easier plant protection
• Weed free cultivation
• Hydroponic (Soil less culture), Aeroponics and Nutrient film
techniques are possible only under greenhouse cultivation
6

8. • Basic cost and operational cost very high
• Irregular power supply
• Little work on designing in different locations
• Cladding material quality/availability
• Lack of technical knowhow
• Lack of indigenous technology
• Lack of suitable varieties/hybrids for greenhouse cultivation
• Exotic seeds very costly
• Poor performance of indigenous varieties
7

9. Greenhouse have been classified based on
shape, utility, construction and covering material.
8

10. Uneven span
Lean to type
Even span
Ridge and furrow
Saw tooth type
Quonset
Ground to ground
greenhouse
9

11. Lean to type greenhouse
• Attached greenhouse
• The roof of the building is extended
with appropriate greenhouse covering
material and the area is properly
enclosed.
• It is typically facing south side.
• The lean-to type greenhouse is limited
to single or double-row plant benches
with a total width of 7 to 12 feet.
• It can draw heat from an already heated
structure and can return excess heat
when conditions are sunny.
• Reduced 10-15 per cent heat load.
10

12. Advantages of the lean-to type greenhouse
• It is usually close to available electricity, water and heat.
• It is a least expensive structure.
• This design makes the best use of sunlight and minimizes the
requirement of roof supports.
Disadvantages of the lean-to type greenhouse
• Limited space, limited light, limited ventilation and
temperature control.
• Temperature control is more difficult because the wall that
the greenhouse is built on, may collect the sun's heat while the
translucent cover of the greenhouse may lose heat rapidly.
11

13. Lean to type greenhouse
12

14. Even span greenhouse
• Two roof slopes of equal pitch and width
are attached to make a single roof.
• Preferred when single small greenhouse
on a leveled ground is required.
• Snow and rain water can slide off the roof
automatically.
• Greater flexibility in design and provides
space for more plants.
• Single span type the span in general,
varies from 5 to 9 m whereas, the
maximum length is around 24 m. The
height varies from 2.5 to 4.3 m.
13

15. Uneven span greenhouse
• Constructed on hilly terrain.
• The roofs are of unequal
width; make the structure
adaptable to the side slopes
of hill.
• This type of greenhouses is
seldom used now-a-days as it
is not adaptable for
automation.
14

16. Ridge and furrow type greenhouse
• Two or more ‘A frame’; or ‘modified
Quonset’ greenhouses connected to one
another along the length of eaves.
• Consists of many even span structures
placed one after another.
• The eaves serve as furrow or gutter to
carry rain water.
• The side wall is eliminated between the
greenhouses, which results in a structure
with a single large interior.
• Interior space reduces labour, lowers the
cost of automation, improves personnel
management and reduces fuel
consumption – Less exposed area through
which heat can escape. 15

17. Saw tooth greenhouse
• Rooftops in the shape of teeth of a saw.
• Designed for tropical warm climate.
• Special design with provision for natural
ventilation.
• Provision of vents on the top and sides of
the structure so that large volumes of cooled
air is drawn into greenhouse.
• It permits a vent area of up to 40%.
16

18. Quonset greenhouse
• This is a greenhouse, where the pipe
arches running along the length of the
greenhouse
• The covering material used for this type
of greenhouses is polyethylene.
• Less expensive than the gutter connected
greenhouses and are useful when a small
isolated cultural area is required.
• These houses are connected either in
free, standing style or arranged in an
interlocking ridge and furrow.
17

19. Interlocking ridge and furrow greenhouse
• In the interlocking type, truss
members overlap sufficiently to
allow a bed of plants to grow
between the overlapping
portions of adjacent houses.
• A single large cultural space thus
exists for a set of houses in this
type, an arrangement that is
better adapted to the
automation and movement of
labour.
Interior view of interlocking ridge
and furrow type Quonset
greenhouse
18

20. Ground to ground greenhouse
• Not suitable for tall growing plants
• Ideal for hills
• Propagation of plant
• Ideal dimension : 9 m width, 30 m
length, 3 m height.
Arch shaped roof greenhouse
• Shape of roof : Round arch or Gothic arch
• Frame of arch shaped roof greenhouse made of steel tubes.
19

21. Shape of different type of greenhouses 20

22. Classification on the basis construction
 Wooden framed structure
 Pipe framed structure
 Truss framed structure
21

23. Wooden framed structures
• The greenhouses with span less
than 6 m, only wooden framed
structures are used.
• Side posts and columns are
constructed of wood without the
use of a truss.
• Pine wood 8 is commonly used as it
is inexpensive and possesses the
required strength.
• Timber locally available, with good
strength, durability and
machinability also can be used for
the construction. 22

24. Pipe framed structures
Pipes are used for construction of greenhouses, when the
clear span is around 12 m. In general, the side posts, columns,
cross ties and purlins are constructed using pipes. In this type,
the trusses are not used.
23

25. Truss framed structures
• If the greenhouse span is greater than or
equal to 15 m, truss frames are used.
• Flat steel, tubular steel or angular iron is
welded together to form a truss encompassing
rafters, chords and struts.
• Columns are used only in very wide truss
frame houses of 21.3 m or more.
• Most of the glass houses are of truss frame
type, as these frames are best suited for pre-
fabrication.
24

26. Basis of
covering
material
Glass
greenhouse
Rigid plastic
Plastic film
Net house
25

27. Glass greenhouse
• Durable and can last much longer.
• The expenses incurred from the
periodically replacing the covering
are eliminated. Overall cost of a
structure is higher.
• Two styles: a) High profile American
greenhouses – freestanding
• b) Low profile Dutch type
greenhouses – constructed in a
ridge and furrow style
26

28. Rigid plastic greenhouse
• Fibre Rigid Plastic (FRP) panel greenhouse.
• Can be bent to fit most film plastic
greenhouse films.
• Reduces the labour of replacing film plastic,
depending on grade, will last 5-20 years.
• Used on permanent metal frame
greenhouse.
• Does not last longer than a glass, but it is
more resistant to breakage and cheaper.
• More uniform light intensity throughout the
greenhouse.
27

29. Plastic film greenhouse
• Warm climates – extensively
used.
• Cheaper than glasshouses.
• Flexible films of plastic
including polyethylene,
polyester, polyvinyl chloride
and polyvinyl fluoride – used
for greenhouse covering.
28

30. Net house
• It is used for cultivation, propagation
and maintenance of young plants in
nursery.
• Shade nets are available in different
shade percentages or shade factor i.e.
15 %, 35 %, 50 %, 75 % , 90 % etc.
• Height of the shade net house ranges
about 3 to 4 meters.
• Now a days different colours nets are
also available i.e. White, black, red,
blue, green, yellow, silver and its
combination. 29

31. • Nets of 40 mesh and higher mesh are effective.
• Control entry of flying insect.
• Save crop from viral disease.
• Netting to maintain an environment which also provide isolation
from insect borne pollen.
Insect proof Nets
30

32. Sr.
No
.
Climate
Factors
Important For Desirable level in
polyhouse
1 Radiation /
Light
Photosynthesis, Photo
morphogenesis, Photoperiodism
50, 000 – 60, 000
lux
2 Temperature Cell division & elongation,
Respiration, Photosynthesis, Water
uptake, Transpiration etc.
25° C – 28 ° C
3 Relative
Humidity
Quality of plant 60% - 80%
4 CO2 Photosynthesis 350 – 1000 ppm
5 Air Movement /
Wind
Influences Temperature, Humidity
& CO2 Condition in the polyhouse,
structural Stability
Inflow: Outflow
ratio should be 1 :
1 per hour
6 Rainfall/precipi
tation
Influences RH, Structural Stability As
evapotranspiration
requirements
Important climatic factors in relation with plant growth
31

33. Energy management in protected cultivation
It is done through
1. Heating
2. Cooling
3. Ventilation
4. Shading
5. Artificial Lightning
6. CO2 enrichment
7. Dehumidification
32

34.  Greenhouse for active heating
 Greenhouse for active cooling
33

35. Greenhouse for active heating
• During the night time, air temperature inside greenhouse
decreases. To avoid the cold bite to plants due to freezing,
some amount of heat has to be supplied.
• The requirements for heating greenhouse depend on the rate
at which the heat is lost to the outside environment. Various
methods are adopted to reduce the heat losses, viz., using
double layer polyethylene, thermo pane glasses (Two layers of
factory sealed glass with dead air space) or to use heating
systems, such as unit heaters, central heat, radiant heat and
solar heating system.
34

36. Greenhouse for active cooling
• During summer season, it is desirable to reduce the
temperatures of greenhouse than the ambient
temperatures, for effective crop growth. Hence suitable
modifications are made in the green house so that large
volumes of cooled air is drawn into greenhouse, This type
of greenhouse either consists of evaporative cooling pad
with fan or fog cooling. This greenhouse is designed in
such a way that it permits a roof opening of 40% and in
some cases nearly 100%.
35

37. Sr.
No.
Name of the part Main Function
1 Foundation Pipe It acts like a connection between the structure and the
ground.
2 Column Vertical member of the structure to support the structure.
3 Curtain wall First several feet of sidewall above the soil line
4 Sill The top of curtain wall
5 Eave Top of the sides of greenhouse
Truss Structure that support the weight of GH and consists of
rafters, struts and chords
4 Bottom Horizontal member to support gutters and the arch assembly.
5 Arches Member supporting covering materials.
6 Bracings To support the structure against wind.
7 Purlins A member that connects cladding supporting bars to the
column.
8 Gutter To collect and remove rain water from the top polythene.
9 Curtains Side ventilation.
Components of greenhouse
36

38. Constrains in greenhouse cultivation system
1. Protected cultivation increase the land, water and fertilizer productivity along
with reduction in pesticide use. But such interventions are associated with very
high initial cost. Although, it is linked with several Government Schemes in
India and have 50-90 % of subsidies depending on intervention, socio-
economic condition and policy of state and Central Government.
2. Uninterrupted and regular power supply is required for operating cooling and
heating system of the greenhouses.
3. Cladding material of required quality is not readily available.
4. Non-availability of tools and implements for facilitating crop-production
operations under greenhouse.
5. There is a lack of major research program on greenhouse crop production in
the country. Region specific technologies are needed in absence of climate
controlled greenhouses.
6. Inadequate or scanty breeding work programs for development of suitable
varieties of crops for greenhouse cultivation. Exotic seeds are very costly and
are out of he Indian growers. Their regular supply is uncertain.
7. There is a problem of pollination in greenhouse crops.
37

39.  Standardizing proper design of construction of poly-houses preferably
region wise including cost effective cladding and glazing material.
 Developing cost effective agro-techniques for growing different crops and
lowering energy costs if any of the greenhouse environment management.
 Developing professional and skilled polyhouse manufactures.
 Creation of awareness among farmers pertaining to the potential of
protected production needs to be strengthened.
 Human resources development is scanty in the country both for structure
development and maintenance as well as crop production technology.
 A mission on protected cultivation in the country under Ministery of
Agriculture, and Farmers’ Welfare is needed.
 Institute on protected cultivation under different major climatic zones of
country are needed to overcome some of the constrains mentioned above.
Future strategies for protected cultivation
38