Protected Agriculture

1
University of Jordan Faculty of
Agriculture Department of horticulture and crop
science Protected Agriculture(0641322) Dr. AZMI
ABU-RAYYAN
2

• Introduction
• It is the intensive cultivation of vegetables
  crops under protective structures (GH, PH, low
  tunnels, hot beds ----- mulch) having many
  objectives
• 1- High quality and quantity.
• 2- Off season production.
• 3- Elongation of growing season (early and or
  delay).
• 4- Higher profit as consequence.
• This is possible, since we are able to manage
• Providing the protective plants with proper Env.
  Conditions (Temp. ?or?, R.H.?or?, light intensity
  ?or? and CO2 ?or?).
• Providing the plants with proper Nutritional
  requirements.
• Providing the plants with well prepared soil,
  free from diseases, using resistant CSV's or free
  from diseases, or using sterilized growing media
  or fertilizer solution in soil less cultivation.

3

• This sector is differing from open field system
  in techniques to be applied but with similar
  basics.
• Points of differences are
• Production cost is much more ? more Efficient use
  of land (vertical extend and increase plant
  population as much as possible.) ? increase
  production ? increase profit. But in the same
  time much more risks (diseases, pollination
  problem fertilizers shortage as a result of
  monoculture and intensive cultivation system,
  heating and cooling problem, ventilation, light
  intensity.
• These risks, make the sector under continuous
  check using developed equipment that enable
  resolving any problems in relatively short time
  as the presence of irrigation system,
  fertilization one, heating, cooling ventilation
  as well as presence of professionals to control
  pests problem effectively.
• All these are costing factors which need a real
  capital to be employed and experienced farmers
  which are able to face and resolve any sudden
  problems in the field or in the market.

4
4-In any time and as a result of high cost of
production ? farmers are ready to use any further
idea to increase their profits or to save their
crops from any sudden problem. This leads in many
cases to unwise utilization of the factors (to
increase production or to overcome the problem)
leading to possibility of very high pollution
than in case of open field cultivation. 5-To
certain extent, you can control time of
production according to the market demand.
(Degree day). 6-Keeping continuous quality of
the product for long period of season. This
standard quality is deeply related to the level
of production factors effectuated and type of
protective structures and their efficiency in
controlling the variations in environmental
condition including covering materials.
5
So, all these points lead to off season
production and increase the production as a
result of intensive cultivation and elongating
the growing cycle ? higher profits (if marketing
is programmed in well manner, otherwise the
opposite will occur. Also protective structures
are highly need for isolation and breading
programs, production of valuable plants as
flowers and indoor plants (that characterized by
high profits) and as nurseries and for hardening
purposes. More than 400,000ha is the area
utilized for production under protective
conditions in the Mediterranean region 2.5 of
that is covered with glass, 17.5 as plastic
houses, 50 is covered with mulch and 23 is
covered with low tunnels. USA, Japan, Holland,
France, Spain, Italy, Belgium, Germany and Grand
Britain are first countries in world in this
sector. Low tunnels, in addition to their
function as nurseries and for hardening purposes.
Also can be utilized for watermelon and muskmelon
and strawberry cultivation. To anticipate melon
production by being covered at early growth
stages. They are proper for farmers of low budget
and can realize a good profit if managed well.
6
Tomato, Strawberry, Pepper, Cucumber, Squash
(Hybrid), Eggplant, Lettuce, Melon and Beans are
the main vegetables to be cultivated under
protection showing two production periods early
April-June and late in Autumn except for lettuce
that could be produced mainly from January-March
(Esbjerg for summer). This not valid for J.V.
early (autumn) from November to February and late
(spring) from March to May or June. Also the
activity of nurseries (for vegetable seedling
production, flowers, indoor plants) is much
related to the planting time of plants in
permanent field (open or protective). They are
well prepared, control of R.H, heating,
parasite----- etc.). In Jordan protection of
vegetables had started in J.V. at 1968 with 2
Plastic Houses in Dir- Alla station. One was
planted with various cucumber cvs while the
other with tomato hybrid cvs .
7

• J.V. is a very big natural G.H in which you can
  produce summer vegetables in winter time without
  heating but under protective structures. But
  there are some limits that decrease the
  production, the quality or some times eliminate
  the production totally as
• - low temp. during clean sky nights ? heat
  inversion.
• low temp. during the 40days (22/12-2/2).
• for improving the quantity and quality of the
  protected vegetables there should be the use of
  protective structures and the covering sheets
  (pH, GH and tunnels). By protection, tomato
  production had increased from 1.5 ton/donum in
  open ? 10 ton/donum of P.H. and 1ton/donum in
  open ? 8ton/donumP.H. for cucumber.
• In 1980s, protection techniques had spreaded to
  hilly land for (1) having early production in
  hilly are and (2) extending it into autumn
  producing in months of off production in J.V.

8
(July, August, September and October). (3) cost
of pest control in J.V. (4) severe depletion of
input resources.
of protected area Tot. vegetables Tot. protected Don. pH Don. tunnel Year
4180 385 3795 1978
8 313243 25050 6911 18139 1994
5.7 429309 24501 8596 15905 1995
11.3 271483 30701 9503 21195 1996
634 2370 460 of ?
9

• The of protective is low because of
• No need to protect all vegetables as roots,
  tubers.
• Protection is highly costed.
• Low income of major part of farmers.
• also increase production ? decrease profit since
  exporting to the outer markets is limited ?
  diversification

10

• Means of Protection
• From non favorable condition
• The non favorable conditions which affect
  negatively the quantity and quality or cause
  death of plants are frost, minimum temp. or
  below, max temp. or above, winds (cold, hot,
  sandy----), high, low light intensity, hail and
  others.
• The means of protection were developed from
  simple to highly sophisticated and complete
  automatic GHs. they are
• Selection of protective place and using the
  proper method of cultivation, (in between
  mountains or in southern side of the mountain or
  south-Eastside to gain earlier warming condition
  and anticipate the spring planting time. Also
  making bed with slope towards south. Planting
  your plants in west or north side of the furrow
  to be directly exposed to sun shine.

11
2-Protecting the planted area by fences (hedges)
(as like 2-3 lines of corn, sunflower, cactus,
roses) against animals, winds, thieves and sand.
These fences can be sufficient especially for
vegetables of bus by growth (not vertical) where
no need to do wind breaks to avoid loss of
certain part of your land by shading and very low
cost of wind breaks construction. 3-Wind breaks
if there is a sever wind, and sandy conditions
they are build to filtrate the prevail wind
(perpendicularly) as like 1)- living plants
(pines, casuarinas ----) in a one or 2 lines
(alternative) according to wind severity (1.5-2m
between plants 2-3m between lines) leaving
about 8-10m in south or east sixes without
planting since wind break will induce shading
later on. Characters of plants to be used are
1) Ever green 2) of high growth rate into the
upright and laterally. 3) Hard wood to tolerate
wind force 4) not to be a source of pests
infections.
12
2) Sterns of semi woody plants to be fixed in
soil or built as not as those corn, sugar can
----- leaving space between each strip and other,
so as to filtrate the strong wind and absorbing
its force 3) nets of plastic strips to
decrease the wind velocity and not to block
(since blocking creates forces behind the nets
which can destroy both the break and crop). So
they are filtrating about 50 of wind speed. Can
be established with more than one line. Should be
treated against negative effect of U.V. light so
as to elongate their life up to 5 years. They
have advantages of non competing your crop on
water or nutrient elements and not to be as a
host for pests. 4) Caps of plants that
protect from winds and sands and can anticipate
the production by rising temp.
13
little bit more than non covered and so non
severe frost is overcome. They are of inverted V
over cucumber against wind, hot tent over melons
during low temp. where ventilation is done by
cutting certain part 3-5cm from the side opposite
to prevailed strong wind and this cut is very
high as plant grown and very high in size up to
be removed as the plant becomes in touch with the
inner side of the cover. Ventilation is important
to get rid of RH and hardening well established
plant. Disadvantages exposing to decrease temp.
after increase temp. can harmful the plants since
during high temp we will have soft, sensitive
plants to cool conditions. 5- Spraying the plant
by mist water when temp. is around freezing level
to release energy (80 cal/gm of water) when
frozen which can to certain extent protect plants
especially if the sprayed water is heated. It is
practically applied for farm of citrus..
14
6- Spraying the plants with foam (as Agri-foam
(commercial name) of Gelatin protein and
stabilizer material for the foam and spreading
one at the night of expected frost. It has been
proved to be efficient in protected melon by very
high temp. 12c gt non treated since treated have
been isolated from atmosphere and energy released
from soil will be conserved for plants. Done by
having source pf compress air to pass through a
sponge surface that covered with foam material ?
small air foams which will be covered with
membrane of the foam material which will an in
volume up to cover plant. 7- Smoking over plant
during frost nights ? Radiahrns Air mixing to
mix the upper warm with lower cold air in calm
conditions. 8- The use beds are cold or hot for
production of seedling early in season when low
temp. is dominating. These beds should
established near farm serves as water and over a
well drained soil and protected by wall of farm
building or behind wind break and well exposed to
sunshine. It is firmed from bed (soil or sand or
mix), over which frames of wood or cement are
established with 45-60cm for northern side
22.5-45 for southern side as height cover frame
(cloth, glass or plastic of 180cm 90cm exactly
as dimension of base bed.
15

• Methods of Heating in hot beds
• Non fermented manures straw with 2 1 ratio
  that prepared 10-14 days before being used as
  covered a pile that moistened and mix each 3 days
  to have uniform decomposition. Then spreading at
  the bed base to 30-90cm height according to the
  time needed to have heating (where 30-45cm gives
  heating up to 3-4 weeks while 60-90cm give heat
  up to 3 months). The base of bed should be well
  drained to draw down the excess moisture which if
  remain will block the fermentation and heat
  evolve. Normally, it is distributed 12.5cm
  manure then pressed uniformly then another one up
  to final height distributing the top a layer of
  soil of 5-15cm for having uniform heat
  distribution and avoiding hot spots that may burn
  plants or seeds. Warm moistened manure shows gt
  rate of decomposition than the cold moistened one.

16

• Hot air released heat of wood, methane or fuel
  burning is carried and pump ed as hot air to end
  of pipes established in the bed.
• Hot water hot water is distributed from burning
  point into various bed points through pipes that
  established at the base and in both sides of the
  bed, pipes volume and eff. Of heater and prop
  sloping of bed an show better heating efficiency.
• Electricity the electrical resistance which
  isolated by covered with lead, is distributed on
  soil surface and soil and along the inner side of
  the bed. Automatic means can be established for
  ventilation, irrigation lt 50g mists ? uniform
  distribution. In case of cold bed, there is no
  heating source. So main source of energy gaining
  inside it is the conserved solar radiation which
  related to type of cover, ventilation is
  important during sunny day at the morning up to
  afternoon not later so as to avoid sever drop in
  temp. during night.
• They are used for
• ear by production of seedlings especially in
  areas of not sever winter.
• hardening of seedling that produced under heated
  structure.

17
In addition to ventilation process which prevents
RH ?. The irrigation is done also during the
morning so as to be dried out before evening
(avoid risks of RH and avoid drop down of temp.
as a result of water evaporation) and avoid
burning spots of leaves by direct sun. 9- Low
plastic tunnels can be used for 1- seedlings
production during low temp. of December and
January. Can be consider as a beds or basins of
90cm 3-4m. that seeded, irrigated then the
tunnel is built over them by using galvanized
wines each 1m (4-5mm as ? ventilation done after
3weeks of seeding if temp. is low. By lifting the
opposite side to prevailed wind during the day
and close during night up to 10-12day before
transplanting where lifting the cover completely
is done. Irrigation is just at seeding time and
if temp. increase another time can be done. 2-
protecting plants of crops during early stages so
as to have early production than open since frost
risk can be avoided and reflected radiations from
soil are maintained under the tunnel and
protection from winds, rainfall ----- How to
build the tunnel ??? after preparation.
18
Which can be from galvanized wires of 4-5mm ?
2m length or from galvanized tubes of ½ as ?
3m length which immersed a 1.5m space in the
soil. Or could be from reinforced metallic wire
of 8-10mm in ? 3.65m that can make an arc of
2m width as like the galvanized tubes. While the
galvanized wire can make an arc 1m in width. P.E
is the covering sheet of 50-80 micron and not
more since it is costed and used and used for
only one growing season or tow while height
ranged from 45-80cm.
19
As the bed base increase, then thickness of the
covering sheet is ?? but within the range of
50-80m. and also sheet width
Type Thickness m Sheet width (cm) Tunnel H. (cm) Tunnel base(cm)
P.E 38-50 130-150 45 40-50
P.E 38-50 180-200 55 80-90
P.E 50-80 200 55 120-130
P.E 80 250 55 140-160
P.E 80 330 80 180-220
20

• Tunnel Length should not exceed 30m to facilitate
  ventilation and improving pollination process (as
  a result of air shaking) for those that need
  pollens.
• gt70 of what reflected will be lost oury tunnel
  this is decrease at presence of water vapor
  film at the inner side of plastic sheet when it
  is of P. Ethylene, the normal type to be used for
  tunnels.
• Small tunnels for seedlings production and early
  protection while bigly ones ? for protecting
  plant even at well developed stage.
• Fiber glass, corrugated type can be used for
  protecting vegetables of home garden, which can
  be used for many times and clean easily but
  dimensions of tunnel should be exactly prepared
  with fiber glass.
• Perforated plastic sheets, can be used so as to
  have efficient ventilation and elimination risks
  related to excess R H in tunnel but this should
  not be highly perforated so as not to loose
  efficient of heating

21

• 10- Floating Covers sheets of poly propylene
  that weighed 14gm/m2. as specific weight. So they
  are light so as to be spreaded directly over
  plants without inducing any damage and leaved
  free in order not to block plant growth allowing
  80 of light tmns.
• 11- Shading against strong sunlight can be done
  by
• covering fruit with straw as like melons against
  suns cold or most of tomato plants. This method
  low drastically of light to reach.
• - production of vegetables under palm plants
  which protect vegetables from high temp., wind
  and direct sun shine in hot areas as Albasre.
• - using plastic nets that spreaded over frames
  (as those of normal tunnels). Of black or green
  color which transmit certain of light according
  to netting intensity, the preferred is what allow
  to 50-60 of light transmittance so as to have
  4000-5000lux of light intensity , They are
  treated against U.V. damage, so can remain for
  3-4 years in a good state.

22

• using of Jute sheets in nurseries to protect the
  tender plants during very high temp. condition or
  for those that considered shade loving plants.
• spraying of time solution over plastic or glass
  covers for one or 2 times to have good shading
  level, stick material can be mixed with solution
  but washing of it later during cold condition
  become more difficult. (washing by spraying with
  5 oxalic acid).
• clay solution to be sprayed over the covers
  during very high temp. season to elongate growth
  and productive life of crop but ??? of
  transmittance light in a noticed manure, so can
  be applied later on when P.S. rare ?? and not
  affect negative the yield.
• - thermo blankets.

23
12- Plastic shelters for protection of tomato
fruits from cracking as a result of heavy
rainfall. This sheet is spreaded over frames of
tomato crops grown in open field but vertically
and also covering the sides exposed to strong
wind that may also port rainfall to fruits. 13-
Plastic houses high tunnels that characterized
by following points in relation to low
tunnels a- Longer period of production. b-
Better vertical expansion and very high plant
density (No. of plants/m2 ). c- Good production
of qualified early crop that gives higher
prices. d- Increase the productivity as it is
possible to improve pollination and fertilization
by using Bumbles and as a real capital is
employed which better factors of services and
cultivation. e- Better exporting activity since
the quality is more and contained for longer
period. f- Easier to prepare the soil, serve
plants and to overcome pests or fertilizer or
water shortage problems. g- Faster cycle of the
capital to have return ? private sectors are
highly involved in this sector -
24

• Glass houses plastic houses are characterized
  by
• More safety against wind than pH.
• Higher efficiency of solar radiation (that
  incident/unit time) transmittance and captured ?
  better energy conservation.
• Easier and better control of micro condition
  under protective G.H. structure than pH since
  they are provided with all facilities that.
• Enable faster conditioning and minimum variation
  between day and might conditions.
• Lower water vapor condensation ? lower risk
  related to dropping of condensate water vapor.

25

• Plastic houses Glass houses are characterized
  by
• Lower construction cost that 1/10 of glass
  houses cost.
• Arc structure of plastic house enable long period
  of perpendicular light/day than GH ? continuous
  transmittance of great portion of incident solar
  radiation.
• Changing the location of your protective
  structure is more easy with pH than GH which may
  occur every group of year for crop rotation
  reasons or for eliminating the risk of certain
  epidemic diseases since possibility of nutrient
  elements shortage and high diseases diffusion is
  very high under intensive cultivation.
• Shading induced by pH frames is much lower than
  that induced by frames and other components of
  GH.
• GH maintenance during its life is more applicable
  and costed more than pH.
• pHs are more adapted for summer and warm areas
  since they show lower warming condition than GHs
  which are more adapted for cold regions and
  winter time ? cooling cost is so gt in GH then in
  pH.

26
Covering Materials 1-Glass that covers that
great part of glass house structure (Roof and
upper party walls), non colored, pure of 3-4mm
for roofs and 2.5-3mm as thickness for walls that
face lower accidental weight. Glass plates
dimension are of 40cm 45-60cm, some time reach
to 100cm length but the smaller the dimensions,
the greater the resistance to any presser and the
lower the risk to be broken and if broken the
lower the cost to be changed gt 90 of incident
light is transmitting and low portion of that
will be lost (to outside) as reradiated easy to
be cleaned and of long duration up 25 year if not
broken, so easy to be broken but not burned,
conserve for-red radiation.
27
2-Plastic either of P.E or P.V.C (poly
vinyl chloride) of 180-200m for plastic houses as
thickness. Treated against negative effect of U.V
light so as to elongate the duration. Also can be
provided with silicon atoms which keep the
expansion rate at low level ? better conservation
of reflected light since remain straight for
longer period than non treated. Double cover of
plastic can be used with a space of 4-20cm (not
more, not less) by pumping the air to the space.
This can increase temp. inside up to 6c greater
than out during the night of winter time. Since
there is a kind of isolation. Easy to be burned,
light in weight, lower cost than glass, permeable
and O2, CO2 but not to water vapor, but of lower
transmittance rate that is about 90 when new
which decrease to 50 after one year. Allow
passing of reflected for red radiation. So loss
of energy from these covers is gt than from glass
and water drop will be condensated and after
being accumulated at these rough surface (inner
side) will drop down over plants ? ? R.H ?
incidence of diseases P.E is more affected by
heat, light so they are changed every 2 years
while P.V.C each 3 years-5 years.
28
3-Fiberglass that used to cover structures that
manufactured from aluminum frames with which easy
to fix the fiber plates, also can be used to
cover tunnels (arc length width of fiber
plate). Also can be used to cover plastic houses
but should be fixed in a special way. (cross in
inverted manner and straight wire over each over
lapping area) plate are either corrugated or flat
of (1.3m7.3m1cm as thick) light in w.t., allow
passing of 80-90 of incident light when new,
this ? gradually with plate aging as a result
of changes induced on plate surface which are
related to environmental conditions (friction of
sand particles that are carried by wind to ?
rough surface that enable development of decay
organisms ? green or black color ? low
transmittance percent). High in cost compared
with plastic and easy to be burned. 4-Cloths to
protect the plants from insects attachment and
shading plants against strong light intensity
also can be used as a second door in plastic
houses, GH. For having efficient control of
insects filtration to cultivated plants with
entrance of labors and technicians. From the
kinds used muslin, agryl.p.17 and agronet.
Raished cover in west bank.
29

• Types of plastic houses used in Jordan
• Local types that make of water pipes that
  prepared manually (arcs are wounded according to
  model frame) from pipes of ½ -1. Width is
  varied from 3.5-7m2-2.5 height of the upper
  point and 1.5 is the distance between each arc
  and other having woody doors and plastic cover
  which is treated against U.V. radiation,
  transparent and of 80-120m and can persist to 3
  seasons.
• Imported types a- Filcluir French, of
  galvanized tubes that reach to mm? and of 64m
  length 7-8.5m width 2.75-3.2m height 1.5m
  between first and arc then 3 or 2.5 or 1.5m
  between each other arcs. They have lefting bars
  as much as No. of arc for climbing of plants and
  rein forcing the arcs to inside they have winders
  for ventilation that can be opened by manawille.
• b- Fornir French, of galvanized iron 50-60mm?,
  reach to 54m length as plastic structure 7-8-9m
  width 2.65-3-3.33m as height. 1m is the distance
  between 1rst and 2nd are then 2-2.5m the other
  arcs are spacing. Having manawella to open and
  close the windows.

30

• Construct ruction of protective structures
• Before the establishing of P. structures, there
  are general conditions and others special to be
  taken in consideration
• The General
• 1- Capital that facilitate the application of all
  inputs needed for the production process (P.
  structures, wind breaks, seedlings production
  from qualified seeds, fertilizers, O.M., soil
  preparation and leveling, irrigation, machines,
  labors cost, transportation, conditioning
  ------etc).
• 2- Presence of water sources or wells or rainfall
  collection as the source is closer, it will be
  better.
• 3- Presence of roods to and from the farm to
  provide it with production inputs and take from
  the frame the product.

31
4- Availability of labors centers near farm area
(especially at the harvest time and planting
time) experienced labors are optimum. 5-
Presence of professional people that can do a
successful management throughout Employing
input factors in a best manner (minimum cost ?
higher qualified input production and lower
impact to the environment (fertilizers and
pesticides). Ready to make any design to face
any sudden event so as to resolve problems
related to that event in relatively short time
and with minimum risks or side effects to
environment. Ready to work with his hands, to
plow, to drive lorry or tractor and not feel the
superiority ? well trained and experienced.
32
Able to use and understand the useful results
of new techs that may ? or improve the production
process as (PH meter, E.C. programming of
irrigation and fertilization and computer).
Able to forecast the productivity of various
crops in his region. 6- Good market facilities
by instructions (cleaning, grading, packaging,
labeling, cooling, distribution) and good
programming for production.
33

• The special factors
• 1- The proper location that protected from winds,
  building shadings or trees, connected with roads
  to and from the location, near to water source
  (good water and continuous), well drained soil
  (sandy to sandy loam), near to labor centers and
  large area that enable any future extend or
  development.
• 2- If wind breaks are needed and natural not
  presented, then the construction of netted
  plastic breaks that allow passing 50 of the wind
  (filtration of wind force) which can ? wind speed
  up to 60 (40 the remain) of total wind speed at
  5 the height and up to 20 (80 the remain) of
  total wind speed at 20 the height of break, so
  180-240cm height are sufficient since these wind
  breaks rises the flow of wind up ward, that means
  above the top of vegetables.

34
3- Direction of protective structures in calm
locations, all types weather simple or multi-span
should be fixed in our region at North-South
direction, with which the solar radiation can
reach to the plants along the day from the both
longitudinal east and west sides and there is
shifting of shading by frames during running of
day hrs. But in windy areas, the blown winds
should hit the structure in a perpendicular
manner with the length of structure body (smooth
hit). 4- Land leveling, sloping
(especially for soil less cultivation), heating,
and establishing of various facilities (election,
irrigation, draining, steam system) taking in
consideration that all these systems are of high
cost and ?? area to be covered is advised so as
to ?? the spent cost of all these facilities/m2
of the covered area and this within certain
limits (not absolute).
35
5- In multi-spans ? sloping of structure to
certain side is important so as to collect the
rainfall avoiding risks related to its
accumulation and also can be used during water
shortage if stored in prepared pools. The design,
also should tolerate the possible wts related to
snow accumulation by having additional supporting
columns. Or to use single units that spaced
longitudinally at 2m. 6- 60m is maximum length of
the structures so as to have good ventilation and
efficient movement and labors activities. 7- 2m
is the minimum width (height) of the main door in
both heads to allow entrance of tractors and
other machines. 8- Keeping the stoages,
management offices , nursery, maintenance serves
at the central part.
36
Construction of GHs that depending on special
designs. The bases are prepared by engineers
since not easy to be done by the farmer and so
should be constructed by certain companies and
what to be awarded by the farmer is the
characters and purposes which can serve our
plants inside the structure where certain part
has been discussed and the part related to
conditioning will be explained later
on. Construction of plastic houses it varies
in certain techniques from company as a producer
(manufacture) to other. Each company has certain
catalog that explain in detail various steps of
P.H. construction where if the farmer follows can
easily do the construction. And the general
method includes 1)Land leveling with
dimensions equal (No. of PH. width ms of
space between each 2 lines) (No. of rows
length of PH ms of space between each 2
rows). 2)Selecting of referring point as a
partition point from which you make the angle of
90 by Fithagoris theory.
37
3)Fixing 2 pieces of as bases for both ends of
the first arc, the longer side in the is
immersed in soil. 4) Connecting the 4 pieces of
first arc by 3 (½? 2?) since arc ? is 60mm.
then inserting this arc over both bases. 5)
Connecting the 2 galvanized pipes of ¾? to the 2
over the soil surface with 2 pieces of
which supposed to fixed in soil as a bases for
the next arc at the right space to the length
of the pipe. 6) Repeating step 4 to make next
arc but by 3 (½? 2?) then connecting first
arch with 2nd with 3 galvanized pipes of ¾? . 7)
Repeating step 6 for each arc until the last one
(first arc from other side) where step 4 is
repeated for it.
38
8)Reinforcing the first arc with the neighboring
one by further pipes that ended with clips from
both ends (4 for each head), these clips are
fixed to pipes by screws. 9) Fixing the main bar
pipes which is of greater ? than ? of arcs by
screws, this bar is at 2m height above the soil
to carry the door 10) Reinforcing the
structure, also by connecting the main bar with
the 2nd arc by other pips that ended with clips
as mentioned in step 8. 11) Reinforcing the
structure by tying the trailing wires to the main
bar from each side. 12) Reinforcing the
structure also by tying both outer arcs of
plastic houses with No. of wires 36-34, (34
8.5m width and 36 for 9m as width). This done by
starting from upper point of the arcs (middle
point) then going in both sloping sides
increasing the space as we are far from middle
upper point (starting with 20cm between each 2
wires as space and ending with 50-60cm down in
both sides).
39
13) Reinforcing each arc from the inner side by
connecting a pipe of (¾? 7-9m length width of
PH.) to hocks (collar) presented over 2nd
presented over soil from each side. These pipes
are also useful in carrying and trailing of the
growing plants where wires that fixed
longitudinally into the main bars, are passing
over these pipes and No. of wire should to No.
of lines of growing crop. 14) Covering the
structure as follows 15) Fixing the doors,
fans, windows and roof ventilation system if
presented.
40

• The use of PHs or GHs
• They are structures formed of iron frames having
  gable (??????) or Quonset (half cylinder) roof to
  avoid water or snow accumulation over the roof
  and so the damages related to these actions.
  Their volume enable entrance of labors, tractors
  and other machines and serving plant in an
  optimum way. They are of high cost but their
  return is profitable especially under the
  following conditions
• No. of structures to be utilized at the same
  time, effort and management (area to be covered /
  complete unit of services). As the area ? (to
  limit 40 structure), then the cost involved /m²
  covered ?? under normal conditions.
• Volume of covered structures (No. of m³of heated
  air /m² of the covered area) proportional
  relationship but from economic point of view it
  is to certain height.

41
3) Types of frames, woody (more shading), or
Aluminum (longer duration), or galvanized iron
25 years and both Aluminum and Iron are more
safety against diseases and pest, since they
cant hide while in woody yes. 4) Type of cover,
wither glass, fiberglass or plastic and its
newly degree. 5) Availability of heating,
cooling, mist, irrigation system and to which
level can be control automatically presence of
pool 6) Presence of most suitable cvs,
protecting condition and tolerating pollination
problem various diseases. 7) Programming of
production to be at off seasons and during
periods of no competition with open field
production. 8) Exporting the production into
outer markets (presence of facilities to export
and compete out side).
42

• In spite of all these considerations, the
  protection becomes necessary in the following
  cases
• In cold regions and during winter for both
  northern and southern sites to line 35 as
  latitude of the earth where heating is required
  and open field in these areas is blocked.
• In Hot regions and during summer, by using
  conditioned GH where open field is also blocked.
• While in temperate region, the protection is done
  by controlling the productive factors at the non
  favorable conditions.
• It is possible to employ the capital in a best
  manner through out the following points
• 40 PH (950m) as one unit.
• Two PH as nurseries for seedlings production
  which can be shaded during summer by black or
  green plastic net.

43
3) Effectuating the drip system to irrigate space
in between PHs so as to be planted with low
plants or covered partially with low tunnels ?
cost of m² to be irrigated ? as area to covered
with drip system ? (within the capacity (pump
filters) of the irrigated system). 4)
Distribution of crops according PHs dimensions,
volume, facilities where most valuable and tender
plants supposed to be in the well prepared ones
and dwarf, strawberry and lettuce in low type..
and those that tolerate high temp. water shortage
in structure of low facilities. 5) Construction
of pool or tank from concrete for collecting the
rainfall and storing also water from other
sources during non shortage time, so as to be
used at water stress or shortage time. 6)
Minimizing cost of construction by use big
plastic houses. 7) Availability of necessary
equipments that can serve in or various activity
and realize profits from various services weather
in or out of the farm.
44
8) Presence of experienced team which ready to
work at any time and any work. 9) Control the
close and open of protective structures to
minimize energy loss especially during winter and
so ?? cost of heating if system of heating is
presented using most economic, efficient and
practical methods for ? temp. during hot summer
in order to elongate the plant cycle with minimum
conditioning cost. 10) Using of hybrid seeds
that characterized by ? productivity and ?
quality in order to achieve profits gt as much as
possible than the spent cost. Since these CVs are
highly adapted to protect structures and for some
crops are planted for more than 4-5 cycle/year
under protection as like lettuce ??? use of
protective facilities.
45

• Shapes of protective structures
• Lean-to-building single, beside building,
  sloping part towards sunshine (south and south
  east).
• Gable uneven span for both PH or GH, but over
  sides of hills so it is adapted to sloping area,
  can be single or multi-span but more adapted to
  single.
• Gable even span, for both PH or GH, multi or
  single and it most diffused for GH over leveled
  land.
• Gothic arc of the roof that shows pointed upper
  part.
• Elliptical or modified Quonset that more diffused
  for multi-span of PHs.
• Quonset or half cylinder just for single and
  more diffused for PHs.
• Methods of controlling the environmental factors
  in

46
protective structures It means to control
environmental factors of atmosphere, soil factors
in order to realize as much as possible the
optimum conditions for plant growth ? greater
return/cultivated unit. The factors to be
controlled are 1)Temp that can be modified by
heating, cooling,., which should be utilized
after understanding the basic as methods of heat
transport which helps in a-Effectuating the
controlling heating in efficient manner by ??
of energy gaining from solar source during the
day of cold condition and by minimizing energy
loss throughout reflected radiation from solid
heating bodies, plants presented inside the
protective structure ??? cost. b- Increasing the
efficiency of cooling by ?? energy gaining during
cooling the day of hot condition and enhancing
the loss of the gained energy ??? cost.
47
The main methods of heat transmission
are a-Radiation light is presented as
electro-magnetic wave which converted into heat
as incident over bodies. So radiations that pass
in plastic sheets or glass and hit bodies inside
protective structures will change into heat
(continuous rising in temp. of bodies as there is
an incident of light. In the other hand, the
heated bodies radiate energy - loss of their
heat to the cooler bodies (outer) as Far-Red.
This continues as temp. insidegt outside during
night or day. these facts can be useful in a-
in cold weather, it is important to maximize the
solar energy gain during the day by selecting the
right design, direction proper cover that
allowing passing of maxi ratio minimizing loss
of Far-Red. b- In hot weather lower light
permeability to inside higher permeability to
Far-Red outside to get rid of energy presented
which can induce a lot of problems. c- In
temperate regions that are of temperate weather
during day and of moderate cold during night,
then the non permeable cover to Far-Red is
preferred in-order to raise night temp. about
2-3c than out ? heating which could be
in-economic in this case.
48

• According to their permeability to Far-Red
  covers can be subdivided to
• Glass PVC of 350m ? not permeable Far-Red.
• Fiberglass PVC of 75m ? low permeable to
  Far-Red.
• PE ? permeable to Far-Red, but condensation of
  water vapor at the inner side ? permeability
  since water vapor film block Far-Red filtration.

49

• b) Conduction transmit of energy from hot point
  to cold one throughout mean such as loss of
  energy from heated GH of ?? temp to atmosphere.
  than outside through (in both cases) the cover.
  So having more than one cover (double) reduces
  heat loss by condition because of isolating space
  while in other case (gaining no need of double
  cover). Double cover is related to heated
  structures and not to these depend on Solar
  Radiations
• Convention infiltration the structure body and
  plants presented inside are reradiating heat
  (after being heated by incident light) which will
  be carried by the means as air or water ?? their
  density (heated means) ? raising of air or
  changing water or condensate water into water
  vapor and going up to be replaced by colder air
  which in turn will gain energy and soon
  circulation loss of energy as the heated means
  come in touch with cover or some filtrated
  throughout cracks, openings
• Energy reflection from sealed surfaces as the
  reflection of the light from sealed ironic
  surfaces as Far-Red.

50

• Energy lost by conduction is expressed in British
  thermal units (quantity of energy needed to
  raise temp. of 1pound of water a 1F)/this
  quantity to be lost through 1ft²/hr when the
  outer temp. is 1F lower than inner one.
• Infiltrated energy is expressed in No. of air
  changed of protect structure/hr. energy loss by
  conduction is referred to a medium wend speed of
  24km/hr.

51
Reflection (of total loss) Infiltration 1st study 2nd study Infiltration 1st study 2nd study Conduction Btu /ft2 / hr Type of cover
4.4 1-2 2 1.13 Glass
1.0 0.75-1.5 1 0.95-1.00 Fiber-glass
70.8 0.5-1.0 0 1.2 P.E-one layer
---- ---- 0 0.7 P.E-two layer
---- ---- 0 0.6 P.E-two layer
52

• by increase No. of layers ? ? heat loss and it
  has been proved that the most efficient in
  reducing heat loss is 3 layers of glass with 6mm
  space between each 2 layers while the lowest is
  fiber glass, then P.E of one layer but of 50-150M
  then glass of one layer (glass gt P.E gt fiber in
  reducing heat loss when of one layer). Other
  traits as P.E (2layers), PVC (2layers) had showed
  medium results.

53
Calculation of needed energy for heating There
are many equations, but each needs a lot of data
input and factor for each input of the equation,
where it is likely difficult for farmer to have
all data and factors. So it is diffused to use
simple equation HUA(t1-t0) where HEnergy
needed in British thermal units/hr UConstant
which related to type of cover (energy lost by
conduct in Btu/ft²/hr. which explained before) at
a medium wind speed of 24km/hr. Which increase at
presence of wind than at calm condition AOut
surface area of protective structure in ft².
t1Inner temp. in F, t0outer temp. in
F. For example, if U value of P.E cover (one
layer) is 1.15 Btu, then how many Btu are needed
to raise temp. inside 10F than outside of
protective structure that has a surface area of
1000ft² H1.15 1000(10)11500Btu/hr.
54
How to calculate surface area of the structure?
In case of Gable structure (even span one) Sum
(area of 2 rectangle along the structures)
(2rectangle in both heads) (2rectangle of the
roof) (2triangle over the rectangle in both
heads). The triangle area ½ base H as it
supposed to be of equal bars (lines from upper
angle to the base. In case of half cylinder ½
(2 p rL2 p r²) where p 3.14, r Distance of
highest point in the arc from the soil, L
plastic house length. But very important to
remember that volume of protective, efficiency of
heating system and the environmental conditions
dominating outside are factors to determine No.
of hrs of heating system running to raise the
inside temp. to the required level. This done,
practically, by fixing thermo regulator
(Thermostat) to operate automatically leading to
run and stop of system when temp. drops or rises
respectively, even can be connected to
ventilation system and to cooling apparatus.
55
The Thermostat to be used should be of high level
of sensitivity in order to feel small variations
in temp. so as to 1- Makes order directly and
at proper time 2- Avoiding deep changes which
may damage plants 3- Save in cost of
conditioning . Also the following points can
enable working of thermostat in efficient manure
a- location at a representative position where
accurate medium temp. can be recorded . Far
from blowing wind and from lower side of plastic
or glass cover. b- it should be always in a
position parallel to growing point level. c- not
exposed to direct sunshine, but in perforated
woody box that painted with white color, or the
box should be provided with fan to keep uniform
temp. level by cont. blown of gentle wind. d- an
other thermostat should be established in the box
which supposed to do alarm at 10c (during
winter) and this alarm should be transferred into
bell presented in the house of the farmer to
inform about dropping of temp. to that level
which means blocking of heating system and should
be repaired before reaching 0c (you have enough
time for repairing). Same thing can be done
during summer (alarm at 35c for example).
Indicating that cooling system is blocking.
Source of electricity to the all arm, should be
separate to avoid any trouble in its function
induced by electricity stop by other machines. e-
keeping a mercuric thermometer in the box to
evaluate the accuracy of electronic thermostat
from time to time.
56
To save in the energy consumed by heating
system the following points to be noticed 1-
Protective structure and its design. 2- Type of
cover (max permeability to light minimum loss
by conduction, convention, filtration and
reflection). 3- No. of layers where the thermal
condition factor ?? as No. of layers ??. 4- To be
protected by wind breaks to minimize the negative
effect of the wind by ?? wind speed factor. 5-
Level of control (close, cracks..). 6- Uniform
distribution of heating system and not to be
concentrated beside the outer walls of stricture
to avoid great loss of energy by conduction and
replacement the hot air with cold one at the mid
area.
57
7- Good and efficient ventilation (planning is
very important) may decrease or avoid using of
cooling system especially in temperate area. 8-
Using of shading nets, lime or clay may also ??
cooling costs and the use of thermo blankets to
protect plants from direct sunshine and ?? loss
due to reflection during winter ?? area to be
heated. 9- Presence of plastic tubes beside and
along he plant lines that are filled with water
which gains energy during the day of reradiate it
to the atmosphere during the night may ?? heating
costs.
58

• The use of double plastic layers
• to ? the factor of heat conduction, that can be
  realized by keeping a space of at least 4 cm of
  pumped air and the space not to exceed 20 cm to
  have effective isolating process, otherwise 1-
  if space lt 4cm , the it is possible to loose the
  isolating feature since both plastic covers come
  in touch and become as one layer. 2- if space gt
  20cm ? blowing or movement of air ? circulating
  air from inside portion to outer portion with the
  space ? continuous energy loss.
• Normally inner layer of 100 m and the outer one
  of 150 m and presence air pump to keep continuous
  isolating layer.
• Main characters related to double layer use
• Decreasing the heat conduction factor from
  1.35?0.7 this leads to save in heating or cooling
  cost up to 40.
• Minimizing or avoiding the condensation process
  ??? the possibility of diseases diffusion ? more
  safety condition for plant growth and production.

59
3) Decreasing the heat conduction factor from
1.35?0.7 this leads to save in heating or cooling
cost up to 40. 4) Minimizing or avoiding the
condensation process ??? the possibility of
diseases diffusion ? more safety condition for
plant growth and production. 5) The inner layer
represent a second barrier for plant protect by
which possibility of damage if the outer is
broken is very low since the inner can also
protect them. As disadvantage ?? the of
light transmittance from outside to inside which
can be critical at cold regions ? need heating or
to be during night.
60

• Methods of heating
• for any method, the thermo regulator is very
  important to control running and stopping in
  order to have temp. continuously within the
  required range, central heating system is more
  preferred at multi span to ??cost of heat/m².
• By hot water or steam water Boiler to heat the
  water, then transferred as hot or steam in pipes
  which during it is circulation will radiate
  energy and conduct air to pipe will gain energy
  from heated pipes.
• Thermo regulator is directly connected with pump.
  
• In order to induce (throughout signal) pumping of
  hot or steam water as temp. drops to lower level
  accepted or programmed. An other regular is
  connected to boiler to control temp. of water in
  boiler at a range of 80-85c incase of hot water
  and at a 102c incase of steam water which will
  be delivered to circulating system throughout
  automatic value which not allows return of
  condensate water after its circulation to the
  boiler except from other side so as to be heated
  again up to water vapor state.

61
Un uniform heating efficiency is the
disadvantage, since plants close to pipes may
damage by being heated gt far plants. This may be
minimized by distribution of pipes uniformly over
plants in the mid area and in both side along the
structure to avoid formation of circulating air
from sides into mid area that reach to the plant
in mid area after loosing great part of their
energy since during circulation will touch inner
surface of cover . 2- Hot air hot air will be
generate in hot generator (electrical or by
fuel). Then hot air will be blown inside plastic
tubes (of 50cm ? perforated of 5-7cm ? of each
open) by electrical fans. These tubes are fixed
above plants along the structure at 10m space
incase of multi span ? heating capacity is 500m²
/ tube. It is also effective in ventilation
system. 3- Kerosene or Paraffin heaters (So2 )
??? ??????? ???? ??? ??????
62
4- Electrical heaters that release heat from
radiated tubes which may also connected to fans
that blowing wind across these tubes to
atmosphere of protective structure, of high
cost. 5-Solar radiation formed from isolating
pool, collectors with tubes of radiant mulch,
radiant mulch spread along protective structure
beside lines of plants over the soil surface,
isolating main lines to connect pool with
collectors, collectors with pool, pool with
protective structures and protective structures
with pool and pumping system photo cell
computer system
63
Cooling methods That are applied during hot
summer condition. They are applied in the regions
of mean monthly temp. up to 40c and the max of
48c-50c (were open field production is
impossible) low RH that drops up to 15 which
is below the optimum level required for plant
growth, pollination, fertilization of flowers and
fruiting. So to produce, it is important to drop
temp. about 15c ?? RH up to 70-80, so
cooling of protective structures is the only
solution 1- Cooling by mist system or fogy by
pumping the water under n pressure, water will go
out through atomizers (Nozzles) in a mist form or
fogy form (fine water drops) ? which easily
evaporate ?? temp. ? RH. This process needs a
lot of water (pure that nearly free from salts) ?
- By ? RH ? Better pollination, fertilization
and fruiting. - By ? Temp. ? Better conditions
for plant growth. providing plants with certain
portion of needed irrigated water. But may induce
flooding of soil of structure. So passing area
can be covered with sand. Or planting in straw
pallets that may absorb most of misted water.
64
2- Fan and Pad system the pad that formed from
cork cells will be fixed in the front wall and
over which a group of drippers are established
for continuous moistening of the cork cells,
while the suction fans of the air from inside are
established in the opposite wall. By succession,
the air pressure inside drops down ? flushing of
colder air from outside to equilibrate the
pressure and so will pass through the cells
(moistened) having low temp since touchs the
cells during its passing. Regulators for fans
working and for opening and closing the valve of
dripping system over the pad are required. Fans
should be fixed in the side receives calm wind
while the pads are fixed in blowing wind side.
More eff. occurred as the lines of plant are in
straight rows along with wind passing inside and
at or over plant growing points level. The
entered air will be resisted by plants ? slow
shifting up ward from plant to other (at a rate
of 1m/8m distance 7) so a sheets of plastic
(transparent) are hanging, from top of structure,
vertically over growing points of plants at 10m
space along the structure in order to shift the
air movement down ward between plants lines. If
the pads are near the soil surface while plants
are grown in beds, then a sheet of plastic should
be fixed in front of pads under the beds surface
to shift the running air to wards the plants (up
ward). Also temp. will not be uniform in the
structure (?? in the angles where pads are not
presented and as the structure is longer then
eff. of cooling ? lower in mid area).
65
The eff. of cooling depends on 1)Distance
between the pad and the fan, if it is gt 33-45m,
then the fans should be of greater capacity to ?
the rate of air succession. Or dividing structure
into 2 units ?shorter the distance between pads
and fans. Normally each 250fts of succession
air/mint, needs ft2 10cm thickness of pads
area. 2) The area of the pad. 3) The location
and its elevation above sea surface, since the
air density ?? with elevation. So elevated
locations means more effectuation of succession
since cooling depends on air (prevue) but not on
its volume. ? needs more succession to induce
good differences to have flown of air. 4) Light
intensity in the structure, direct relationship,
since light intensity induces energy or heat. ?
more succession to have better cooling. X shading
if at summer conditions. 5) RH in out
atmosphere, as it is ??, then their will be more
eff. in evaporation (cooling of cells better
cooling) while at 80 of RH ? cooling will be
inefficient since air temp. ??? cant induce
cooling.
66
Ventilation which is important in 1)?? temp.
rapidly ??? the cost of cooling or intemperate
region cooling can be blocked. 2)Renewing the air
in structure ? keep normal CO2 conc. 2)??the RH
of the atmosphere in structure ?? the
condensation rate ??? possibility of diseases
diffusion. It can be By a-Through openings
(windows) in both sides and in the roof when the
air change normally or naturally by raising of
warmed air up and flushing of cold air from
outside through openings to replace the worm one.
As the area of openings ?, ? faster air change ?
faster ?? in temp. the area of openings should
not be below 17 of total structure area. As
temp. ? then openings area should ?? but not
forget to close those that facing the wind at
windy conditions. These openings can be covered
with cloth layer (muslin) and opening is
operating either manually or automatic by being
connected to thermo regulator.
67
b) Throughout succession fans openings that
used in big structures with which the natural
ventilation is not sufficient same establishment
as (pad fans) but instead of pads the openings
can be covered with cloth or free at summer
conditions the fans are connected with thermo
regulator. The efficient fans are those that can
change the air of structure one time/mint
noticing that area of openings should be 4-5
area of used fans. C) Through out perforated
plastic tube using the same apparatus of hot
air, but the air to be blown is the cold or
conditioned one. That distributed at 10m space
and the holes are of 5-7.5cm in ? while tube it
self of 50-75cm as ?. Also this tube can be used
for ventilation during cold condition by
connection it to succession fan and from other
side to opening in wall which will induce vacuum
in tube ? flushing of air from out p. structure
to tube that will distribute the air in structure
gently with out damaging or harm plants as if
entered to structure directly as cold air.
68

• The fan and outer open are connected to regulator
  to induce opening and running of fan at the same
  time (simultaneous). Eff. of fan to success is
  important in order to ? the difference of temp.
  between outside and inside and those of 2ft³/mint
  is optimum, more uniform air distribution can be
  realized by fixing an other fan at opened wall of
  structure to push their inside in an equal force
  to that of sucking air which also can continue to
  push even after the block of sucking one ? better
  uniform distribution of air ? good ventilation.
• Control of light intensity, period ? either ?
  or ?
• ? light intensity by using shading plastic nets
  where the degree of shading depending on
  intensity of tissue knitting (????? ??????) that
  can realize 10 to 90 of shading. By lime
  solution during summer time at which light
  intensity ????? temp. degrees, since a great
  portion of light converted into energy. More
  applicable to shaded or in mental plants and to
  seedlings. This layer should be washed as cold
  season started.

69
b)? light intensity applied as the angle light
incidence become sharp or at cloudy days as what
occurred in northern hemisphere at winter time.
CO2 fertilization ?? light intensity ? high
photosynthesis is the indication for importance
of light. It is practically done by artificial
light (Tungsten or phlorecent light) or both
light types 1- first rich in infrared ?? temp.
as it is a source of energy. 2- second rich in
other light spectrums than infrared ? Efficient
in photos. that is highly at 480nm and 680nm.
Also, structure dimension, cover type,
structure form, cleaning of cover are important
factors to ? light intensity, cleaning by 5 of
oxalic acid then water at the beginning of each
winter. This oxalic acid can react with lime and
pulverizing it.
70
Interaction of light intensity X Temp. X CO2
Conc.
71
C) Control of period positively (more) by
artificial light or negatively (less) by dark
blankets to be fixed over plants ?exact No. of
dark or light hrs. Control of CO2 Concentration
in atmosphere of structure If the structure
remains closed (especially during winter
timeHeating) ? CO2 conc. ?? especially at mid
day (?? temp.) X artificial light X active
vegetative parts ?? photos. Rate. For example if
CO2 conc . ? to 160 ppm ? decreases in photos up
to 50 while if CO2 level ? from 335 ppm to
1000ppm increases the photos up to 100
especially at ?? temp X ? light intensity to
avoid the limiting of photos by any of the 3
factors (any one if limits photo ?((?????even if
others are at optimum conc. The best 30c X
1300ppm CO2 X increasing in light intensity up to
3000f.c. (30,000lux).
72

• Response of vegetables to CO2 fertiliz