Low, medium, and high cost polyhouses are classified based on their environmental control capabilities. Low cost polyhouses use locally available materials and have no specific controls. Medium cost polyhouses use fans and cooling pads for some control. High cost polyhouses are fully climate controlled with sensors, durable frames, and precision growing conditions. Other types include plastic tunnels, net houses, and trench polyhouses suitable for hilly regions. Site selection considers soil quality, water access, slope, and transportation. Polyhouses allow year-round production with higher yields, quality, and disease resistance than outdoor farming.

1. TYPES OF
POLYHOUSE

2. POLYHOUSE
A polyhouse is a special constructed structure
like a building for growing plants under
controlled condition. It is covered with a
transparent material as such permits entry of
natural light.
Difference between Polyhouse and Greenhouse……

3. A polyhouse or greenhouse is actually the same
thing. Traditionally the greenhouse were
constructed on wooden frames where glass was
used as a covering material. On the advent of the
plastic technology, it become possible to replace
the glass with plastic material. As the polythene
material, being the most popular the green house
came to know as polyhouse in resent time.

4. Types of polyhouse
 Low cost or Naturally ventilated polyhouses.
 Medium cost or Partial climate controlled polyhouses.
 High cost or Fully climate controlled polyhouses
 Plastic low tunnels
 Net houses

5.  Low initial investment
 Constructed with locally available
material such as bamboo, timber etc.
 No specific control devices for
regulating environmental parameters
inside the polyhouse.
 Suitable during cold weather,
especially in hilly areas.
LOW COST OR NATURALLY VENTILATED POLYHOUSE

6.  The structural frame is made up of
galvanized iron pipes.
 Exhaust fans are used for ventilation, these
are thermostatically controlled.
 Cooling pad is used for humidifying the air
entering the polyhouse.
 These are suitable for vegetable cultivation
during mild winter and mild summer for the
low hills in NW Himalayas.
MEDIUM COST OR PARTIAL CLIMATE CONTROLLED POLYHOUSES

7.  Consists of sensors.
 Frame is made up of iron or aluminum.
 Designs are dome shaped or cone shaped.
 These are highly durable, 5-6 times costlier.
 Growing medium used in these type of
greenhouses are Peat, Perlite, Vermiculite,
Rock wool.
 In India coco fibres and rice husks are used
as growing media as these materials are
cheaper.
 Fertigation and pesticide sprays are done by
fogging machine.
HIGH COST OR FULLY CLIMATE CONTROLLED POLYHOUSES

8. Miniature form of polyhouse
 Protect the plants from rains, winds,
low temperature, frost and other
vagaries of weather
Provide the best way for off season
vegetable nursery production by
modifying the microclimate around the
plants
 Nursery bed of size 3x1x0.15 m
A portable low plastic tunnel of size
3.5x1.20x1.0 m size with polythene
sheet of 120 GSM is put on the nursery
bed
PLASTIC LOW TUNNELS

9.  Simple framed structure or small row like
structure.
 Nets of 40 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.
 Netting allow controlled sunlight for the
hardening of new plants taken out from
nursery.
NET HOUSES

10. Type of polyhouse –Hilly region
1.Prefabricted polyhouse :
• A prefabricated metal structure
• polyethylene film is covered
over it.
• not for all hill- poor
temperature retention,
• low crop yield, and high
installation cost .

11. 2. Ladakh Polyhouse
 Innovative and low-cost -Ladakh region.
 Difference - its surrounding mud brick wall in place of
polyethylene sheets.
1. Reduces the adverse effects of strong winds.
2. Increases net profit.
 Lean type and has three sides made of mud bricks.
 The back wall is 7 ft in height, while the front has no wall.
 The length is 32 ft with a width of 16 ft.
 The polyethylene is supported on wooden poles and
sidewalls.
 The two sidewalls are descending toward the front.

12. 3. Trench (Underground polyhouse)
• Very simple, cheap.
• Useful underground - hilly region
• Has unlimited potential.
• May be of any convenient dimension.
• Trench of 30 × 10 × 3-ft size is ideal.
• Polyethylene covered -heat loss(night) winter.
• Operations- by removing the polyethylene sheet.
Adv.
• Not require much skill -construction and management.
• Lowest cost.
• Being an underground structure, heat loss is minimum.
• Temperature retention is high & yields good crop.
• Strong winds do not affect polyethylene cover much
• It is long lasting because of underground.
• This structure most suitable for the hilly region.

13. Classification on the basis of structural
shape of frame
Attached : when it is attached or supported by a part of
building or any type of constructed wall.
Detached : when it is free standing position.
Connected : when several polyhouses are joined together
in a series.

14.  A) ATTACHED POLYHOUSE
Advantages
Useful where
space is
limited
Least expensive,
availability of water
and electricity

15. B) DETACHED (FREESTANDING) STRUCTURES:
 Separate structures.
 They can be set apart from other buildings to get more sun and can
be made as large or small as desired.

16. CONNECTED POLYHOUSE

17. Other classifications
The polyhouse can also be classified based on type of
structures, type of glazing, number of spans, environmental
control etc. The various types are as follows.
1.Classification as per type of structure
a. Quonset type
b. Curved roof type
c. Gable roof type
2.Classification based on number of spans.
I. Free standing or single span
II. Multispan or ridge and furrow or gutter connected

18. 3. Classification as per glazing
a. Glass glazing
b. Fiberglass reinforced plastic glazing
c. Plastic film
4. Classification based on environmental control
I. Naturally ventilated
II. Passive ventilation

19. Types of polyhouses –shape and sizes
Barrel shaped
Ridge and furrow type
Saw tooth type

20. Site selection
A good site can make all the difference in the functional and environmental operations of a
polyhouse.
• The soil should have pH 5.5-6.5 and EC of 0.5-0.7 Mmhs.
• Availability of continuous source of quality water.
• The pH of the irrigation water should be 5.5-7.0 and EC between 0.1-0.3 Mmhs.
• Good supply of electricity.
• A ground slope for drainage is an important factor to divert surface water way from the
poly house.
• polyhouses should be located away from the buildings and trees to avoid obstruction to
sunlight and should be pollution free.
• Facility of good road transport to near markets.
• Easy and cheap availability of labourers.
• Communication facility should available at site.

21. Advantages of polyhouses :
 The yield may be 10-12 times higher than that of out door cultivation
depending upon the type of polyhouse, type of crop, environmental
control facilities.
 Higher production per unit area is obtained.
 Reliability of crop increases under polyhouse cultivation.
 Ideally suited for vegetables and flower crops.
 Year round production of floricultural crops.
 Off-season production of vegetable and fruit crops.
 Disease-free and genetically superior transplants can be produced
continuously.

22.  Efficient utilisation of chemicals, pesticides to control pest and
diseases.
 Water requirement of crops very limited and easy to control.
Maintenance of stock plants, cultivating grafted plant-lets and micro
propagated plant-lets.
Hardening of tissue cultured plants
 Production of quality produce free of blemishes.
 Most useful in monitoring and controlling the instability of various
ecological system.
 Modern techniques of Hydroponic (Soil less culture), Aeroponics and
Nutrient film techniques are possible only under polyhouse cultivation.
Nursery for all vegetable crops can be grown
Advantages of polyhouses :…..

23. Plants used in poly house technology are…
Floriculture: Roses, Orchids, Gerbera, Aster, Lilies, Marigold,
Carnation, Chrysanthemum, Anthurium etc.
Vegetables: Mostly exotic such as Asparagus, Broccoli, Brussels,
Sprouts, Squash (zucchini), Celery, Cherry-Tomato, Chinese cabbage,
Leek, Lettuce, Parsley etc.
Landscape Plants: And all types of shade loving plants or foliage plant
which require minimum light for healthy growth.

24. Crops covered under polyhouse
Orchid

25. Crops under Shadenet House

26. Need of Protected Cultivation
• Higher yield
• Year round cultivation
• Better quality
• Off- season production
• Assured production
• Generate self employment for the educated rural youth in the farm sector
• Least pesticide residues
• Controlled pollination
• Vagaries of weather
• Easier plant protection
• Weed free cultivation

27. Future Thrusts
polyhouse technology development has made good progress in India during
the last two decades, and steps necessary for promoting polyhouse
cultivation of flower and vegetable crops have been started. Thrust areas
for future research are enumerated below:
• Conservation of more thermal radiation in winter.
• Durable infrastructure modeling.
• Development of successful commercial models.
• Modernization of polyhouse to permit agroclimatic manipulations of
higher magnitude.
• Identification of new crops/varieties suitable for cultivation inside the
polyhouse.
• Socioeconomic impacts of polygreenhouse technology in hilly region/cold
arid zone.

28. • Plastic films of suitable grades need to be made available in adequate
quantity.
• Development of area-specific suitable polyhouse designs.
• Standardization of package of practices for growing various crops in
polyhouse for specific regions.
• Vocational training to the unemployed youth and polyhouse practitioners in
remote areas to update their skills in this technology.
• Rigorous extension program to disseminate the technology information to
the poorest of the society.
Future Thrusts:….