Polyhouses

K. Gopi kumar
RHM/07 - 25
AP Horticultural University

Introduction
• In open field conditions, there is no control over the
environmental factors like temperature, light and
relative humidity.
• The advent of modern greenhouse technology
opened up the avenues to precisely control the
environmental parameters favourable for the
cultivation of a particular crop.
• Growing ornamental crops in protected
environment (greenhouse/polyhose) ensures the best
microclimate around the plant so that the plant can
exhibit its full potential.

What is Polyhouse ?
A polyhouse is a specially constructed
structure like a building for growing plants under
controlled conditions. It is covered with a transparent
material as such permits entry of natural light.
A polyhouse or greenhouse is actually the
same thing. Traditionally the greenhouses were
constructed on wooden frames where glass was used
as a covering material. On the advent of the plastic
technology, it became possible to replace the glass
with plastic material. As the polythene material, being
the most popular, the greenhouses came to kwon as
polyhouses in recent times.

Advantages of Growing Ornamental
Crops in Polyhouse
 The productivity per unit area is very high in polyhouses.
 The produced flowers will be of high quality without any
blemishes and are suitable for export.
 Insect, pest and disease control is relatively easy in protected
structures than in open.
 Production during off season is possible only under
polyhouses.
 Efficient intensive propagation of high value ornamental crops
is feasible in protected structures.
 Polyhouses provide the right environmental conditions for
conservation, intensive cultivation and exploitation of rare
ornamental plants.

Types Greenhouses
 Gothic arch
 Curvilinear
 Curved eave
 Dome
The most important feature of greenhouse is how to
design to take advantage of sun light in available land
position. The basic types of greenhouses are:
 Even-span
 Uneven-span
 Lean-to
 Quonset

Types Greenhouses
To the extent of environmental control,
the existing green house structures can
be classified as:
• High cost (fully controlled greenhouse)
• Medium cost (partially controlled)
• Low cost (without any controls)

Planning and Designing a Low Cost Polyhouse
•A greenhouse should be designed to withstand the load
of the covering' material, other structural components,
wind velocity; intensity of rain, hangingweights
included in the polyhouse etc.
•Adequate quantity of sunlight for crop production is
required. The structure should require minimum energy
to maintain the desired crop microclimate.
•Local climate conditions and locally available materials
must be taken into account to arrive at the most
appropriate greenhouse design.
•Therefore, the structure is location specific and crop
specific.

Site selection
A good site can make all the difference in the
functional and environmental operations of a polyhouse.
• The soil should have pH of 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 green house.
• Greenhouses 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.

Orientation
Orientation of the
greenhouses could be in any
direction when they are in
single spans.
Multispan greenhouses
should be oriented in north
south direction only, to avoid
continuous shading of
certainportions of the
greenhouse by its structural
members.

MATERIALS FOR CONSTRUCTION
MATERIAL REQUIRED FOR GREEN HOUSE : SIZE : 28 X 20 m = 560 Sq. Mt.
Particulars
Dia/Unit
(mm)
Length
of
Pipe
(Mtrs.)
Qty.
Total
(Mtrs.)
No. of Pipes
Required
(6 Mt. Each)
Insert Pipe 40 NB 1.2 30 36 6
Column 50 NB 6 14 84 14
Column 50 NB 4 16 64 16
Bottom
Bottom
50 NB
50 NB
8
4
5
18
40
72
5
18
Arches 32 NB 5.7 28 160 28
Contd…2.

Hockey With Member 40 NB 6 24 144 24
Member
25 NB 2.3 28 32 14
25 NB
2
28 84 10
15 NB 1.06
14
15 3
Tie Bar 25 NB 6
8
48 6
Cross Bracing 25 NB 5 8 40 8
Purline 32 NB 4 80 320 80
Curtain Pipe 15 NB 6 18 108 18
Runner Aluminum Mtrs. 4 96 384
Zig Zag Springs
Plastic
coated
2 MM Lumpsum 800

Contd…3.

Gutter Coil
(600 mm 1.0
thick)
Kgs.
Lumpsum 180 180
Polyfilm Sq. Mtr. Lumpsum 1300 1300
Shading Net Sq. Mtr. Lumpsum 400 400
Clamps & Hardware - Lumpsum 560 560
Door Frame 1 x 2 Mtrs. Lumpsum 1 1
Insect net (40 Mesh) 2.00 Mtr X 100
Mtrs.
Lumpsum 200 M2

Fogging & Drip
System
Lumpsum 1 1
Source: Dept. of Horticultre, Govt. of AP

MATERIALS FOR DRIP IRRIGATION
SPECIFICATIONS FOR GREEN HOUSE IRRIGATION
AREA OF POLYHOUSE 560 Sq. Mtr.
Dripline Spacing 1.2 Mtrs.
Dripline Spacing
16mm with 0.3 Mtrs.
Spacing with 2 LPH discharge.
Sl.
No
.
Material Unit Qty.
A. HEAD UNIT

1 Dis. Filter 1.5" Nos. 1
2 Plastic Ball valve 2" Nos. 1
3 Pressure guage Nos. 1
4 Fertilizer Injector/Ventury
Assembly
Nos. 1
5 1" Air release cum vaccum
breaker valve
Nos. 1
Contd….

MATERIALS FOR DRIP IRRIGATION
B supply manifold
1 RPVC 50 MM/ 6 Kg/CM2
Mtrs. 12
2 RPVC 40 MM/ 6 Kg/CM2
Mtrs. 48
3 RPVC & G I fitting Lumpsum
C DRIP MANIFOLD
1 Dripline 2016 X 0.3 Mtrs. X 2 LPH Mtrs. 1000
2 Lateral 16 mm Mtrs. 300
3 Cool Net fogger four way (Anti leak) 75
4 Star Nipple 16 mm Nos. 75
5 Rubber Gromet Nos. 75
6 Reducer 17/16 mm Nos. 75
7 PPBV 50 mm/PVC ball valve 50 mm Nos. 2
8 PVC sub main flush valve 2" Nos. 4
9 Pressure regulator 1.5" (Bypass) Nos. 1
Source: Dept. of Horticultre, Govt. of AP

Construction of Low cost Polyhouse
20mts
28mts

1. COLUMN 6.0 m, 50 NB ( 60 mm
OD) 2 mm THICK
2. COLUMN 3.8 m, 50 NB ( 60 mm
OD) 2 mm THICK.
3. BOTTOM 8.0 m & 4.0 m, 50 NB
( 60 mm OD) 2 mm THICK
4. CORRIDOR/HOCKEY 40NB ( 48
mm OD) 2 mm THICK.
5. TOP CHORD 6.4 m, 32 NB ( 42 mm
OD) 2 mm THICK.
6. SMALL CHORD 5.7 m, 32 NB ( 42
mm OD) 2 mm THICK.
7. PURLIN 4.0 m, 32 NB (42 mm OD)
2 mm THICK
8. GUTTER PURLIN 32 NB (42 mm
OD) 2 mm THICK
9. BRACING – 25 NB (33 mm OD) 2
mm THICK.
10. G.I. WIRE
11. CURTAIN OPENING SHOFT 15
NB (3 mm OD) 2 mm THICK.
12. POLYETHELENE UV STABLIZED
800 GUAGE/ 200 MICRONS.
13. INSECT NET / 35% WHITE /
WHITE SHADENET ALL
AROUND 3 mts. HEIGHT FROM
TOP NET.
14. 50% WHITE / WHITE SHADENET
ON TOP.
DETAIL SKETCH AND SPECIFICATIONS OF
FLORICULTURE POLY HOUSE
SIZE 20 M X 28 M = 560 M2
3

TECHNICAL SPECIFICATIONS FOR POLY
HOUSE
1. AREA: The Polyhouse of 560 Sq. Mt./ size: 20x28mts Which is the
minimum for growing commercial flowers for local/retail market.
2. DESIGN: Aerodynamic, galvanized tubular structure and Naturally
Ventilated
3. HEIGHT UNDER GUTTER: Gutters are necessary to drain off the
rainwater and to prevent the rainwater penetration in to the Green
House. The height under gutter should be minimum about 4 Mtrs.
The trapezoidal shape aluminum sheet/ G.I sheet of 1 mm thick and
600 mm wide should be provided all along the length of the Green
House without any joint.
4. CENTRAL HEIGHT: 6 Mtrs. A central height of 6 Mtr. with top
ventilation should be provided to manage the temperature.
5.FOUNDATION: The footing of foundation should rest on
undisturbed soil at a depth of about 0.6 Mtrs. and with a
diameter of 0.4 Mtrs. below the ground surface. It is not
necessary to build through foundations below the sidewalls
and gables but only concrete (P 1: 3 : 6) point foundation of
0.19 cu. Mtr. below the vertical stanchions. Foundations has to

Line diagram for foundation

HOUSE

HOUSE
5. VENTILATION: RIdge ventilation, permanent open top
vent of 80 cm and two sides manually operated curtains. Very good
ventilation is very important for the production of quality flowers
throughout the year. The area of the ventilation openings should be more
than 19% related to the floor area of the green house. The air exchange
rate should be 50 - 60 times the green house volume per hour. The rollup
ventilation has proved very efficient. The plastic film is fixed at the gutter
and rolled up on a pipe. It is very important to fix the film exactly on the
horizontal pipe at the beginning, so that the pipe remains horizontal
during operation. The horizontal pipe with the film has to fit tightly at the
vertical stanchions and must not move away from the construction by
wind forces.
6. STRUCTURAL FRAME: G.I. Pipes of 0.5 to 2.0 inches
diameter. Trusses, Columns, beams as purlins made of G.I. pipes angle
iron should have different load bearing capacities and should remain
sound. The structure should withstand a wind velocity of 100 to 110
Km/Hr. All structure should be assembled by using nut bolt M 10 and M 6
size and clamps which are cold galvanized. All G.I. pipes should be ISI
marked hard dip galvanized ( “ B “ Class), 2.00 mm thick.

HOUSE
A frame polyhouse structure
End view
General view

TECHNICAL SPECIFICATIONS FOR POLY HOUSE
8. Cladding Material: 3 Layered UV stabilized PE film
with a thickness of 800 gauge 200 microns. Plastic film
has to be fastened at the construction and fastened tightly.
9. Fastening Devices (Polylocks): Suitable Aluminum or
steel devices by use of these devices the film can be
quickly fastened and be removed from the structure.
10. Zig – Zag Springs 2 mm steel plastic coated/pup
coated.
11. SHADENET: Plastic woven net (white/white
colour) Shade percentage – 50%. The shade net has to be
supported with GI wire of 2 mm thickness and the net
should be foldable to one side with the help of a pulley
system for smooth operation, 35/white/white shade net all
around 3 Mtrs. Height from top net.
12. INSECT NET: (Rambo Net) : Plastic net ( 60 Mesh) will
be provided under the curtains (permanently fixed).
13. Irrigation System: Drip and fogging system to be
installed from reputed firms as per specifications.

Establishment of Low Cost Polyhouse
Beds
Aisle
Longitudinal layout of polyhouse beds

Cross beding layout of polyhouse beds
Aisles
Beds

Peninsula arrangement of polyhouse beds/benches
Beds/
Benches
Aisles

Government Assistance to the Farmer
1. Area of Low cost Polyhouse: 560 M2
2. Size of the Polyhouse: 20 x 28 Mts.
3. Total cost of the structure Rs. 4,30,000/-
4. Subsidy – 50% or maximum of: Rs. 1,82,000/-
5. Farmer share: Rs. 2,48,000/-

Some Conditions of Tripartite Agreement
for Availing Subsidy
1. That the First Party(the company) should complete the structure with in
stipulated time of 30 days from the date of Agreement as per
specifications, design given by Department of Horticulture.
2. That the First Party (the company) should take up post construction
services when ever the Second Party required, up to one year on free of
cost including materials, and for second year and third year onwards, cost
of services free and material can be charged from Second Party.
3. That the Second Party (the farmer) is responsible for depositing the non-
subsidy amount in bank within 15 days, if loan is not availed by Second
Party.
4. The Second Party(the farmer) should under go training for 7 days in
Training Institutes (Horticulture Training Centre, Hyderabad / Pune)
5. That the Third Party (Department of Horticulture ) should obtain
agreement bond with Companies(first party) & Farmer (second Party).
6. If the project in not completed with in a stipulated time as per guidelines,
the Third Party (Department of Horticulture) has empowered to cancel the
project without any notice.
7. The Third Party is responsible for release of subsidy amount to the bank
after fulfilling all stipulated conditions.

INSURANCE
-P. Subba Rao,
Admn. Officer, Oriental Insurance Ltd

Oriental Insurance Ltd, offers a package under section-II of
‘Floriculture insurance scheme’.
Under this section all the structures of polyhouse, cold
storage facility, grading hall, packing facility, store room, drip
irrigation facility etc. will be covered against perils like fire,
lightning, machinery breakdown, riot, strike and malicious
damage, explosion, terrorist damage etc.
The rate of premium is Rs.1.10/mille/annum
(additional premium @0.30/mille if cover extended to flood
risk).
-Indian Horticulture ‘2000, Vol:44, 4-5.

Economic Analysis of a
Unit
Farmer: Ch. Trinadha Srinivasa Rao
S/o Satyanarayana Rao
Vattigudipadu (V),
Agiripalli (M). Krishna Dist. AP
Total Extent holding: 5 Acres.
Polyhouse unit Area: 560 Sq. mt.
Year of construction: 2005
Crop grown: Carnations
Crop Spacing: 22.5 x 22.5 Cms
Total No. of plants: 12,800

UnitI. Expenditure for construction
Cost of construction of the unit: Rs. 4,30,000-00
Subsidy from Dept. of Horticulture: Rs. 1,82,000-00
Farmer share: Rs. 2,48,000-00
Total farmers expenditure for construction: Rs. 2,48,000-00
II. Expenditure for planting and maintenance:
1st
year: Rs. 1,30,000-00
2nd
year: Rs. 55,000-00
3rd
year: Rs. 55,000-00
Total: Rs. 2,40,000-00
Total farmer’s expenditure for planting
& maintenance: Rs 2,40,000-00
Total Expenses (I+II): Rs. 4,88,000-00

Unit
III. Yield :
1st
year: 1,10,000 No’s flower stems
2nd
year: 80,000 No’s flower stems
3rd
year: 60,000 No’s flower stems
Total: 2,50,000 No’s flower stems
IV. Marketing:
Marketed at local market, Vijayawada,
@ Rs. 5 to 7/- per stem during 3 years
V. Returns:
Total sale price at minimum rate (2,50,000 X 5):
Rs. 12,50,000-00

Net income (12,50,000-4,88,000): Rs. 7,62,000-00

Companies in Construction of Polyhouses:
• Sriroz Consultants Pvt. Ltd., Pune.
• Netafim Irrigation India Pvt. Ltd., Vododara
• Green Field Industries., Bangalore.
• Hytasu Corporation., Hyderabad.
• Ginegar Plastic Products Ltd., Bangalore.
• Rajdeep Agri Products Pvt. Ltd., New Delhi.
• srihari Greenhouses Pvt. Ltd., Pune
• Pooja Greenhouse Industries., Pune.

References:
1. Horticulture Principles and Practices – George Acquaab.
2. Greenhouse Management for Horticulture Crops– S.Prasad &
U.Kumar.
3. Greenhouse Operations and Management–Paul V Nelson.
4. Floriculture Today – March, 2003; 10–15.
5. Floriculture Today – January, 2005;7-10.
6. Floriculture Today – December, 2006; 56.
7. Indian Horticulture – 2000, Vol-44; 4-5.
8. Annual Action Plan-2007-08, Floriculture/250/06 of
the Dept. of Horticulture, Govt. of A.P.

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