Greenhouse structures in Mediterranean regions: Problems...

Greenhouse structures in Mediterranean regions: Problems and trends

Grafiadellis M.

in

Choukr-Allah R. (ed.). Protected cultivation in the Mediterranean region

Paris : CIHEAM / IAV Hassan IICahiers Options Méditerranéennes; n. 31

1999pages 17-27

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Grafiadellis M. Greenhouse structures in Mediterranean regions: Problems and trends. In :

Choukr-Allah R. (ed.). Protected cultivation in the Mediterranean region . Paris : CIHEAM / IAV Hassan II,

1999. p. 17-27 (Cahiers Options Méditerranéennes; n. 31)

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http://om.ciheam.org/article.php?IDPDF=CI020828

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http://om.ciheam.org/

of -

Abstract: 35 been noticed in

of the plastics films, the development of of some and this expansion. Today a of developed in

of of

of of the

of China, of of Japan and the 138 200 ha o€ the in the applications is the

the middle of 19th the the glasshouses in

scale in noticed. With the the plastics films in the a the

in

the table1 the evolution of the is to this table, Spain is the of

to (1 995) the the to 103.295 ha out of which the

(2700 2300 ha in 2000 1000 the

The main which have influenced the huge expansion of the the followings:

e The climatic advantages of

0 The possibilities of using low the the

c The high heating cost of the

the

of sunny days with high intensities of

(wood, steel, plastic sheets).

The of

VOL 31 17

CIHEAM - Options Mediterraneennes

Table 1. Greenhouses and high tunnels in

2605 Spain 28350

9100

Ex. Yugoslavia 5040

2000 Lebanon 1100

2500

800 Libya 7 Tunisia 1425 Albania ?

Total 103395

in the the table 2 it can be that the of the in is

is also well known that the in these not heated and mainly employed in the of vegetables while the most

glasshouses used in

Table 2. The evolution of the greenhouses of the high countries

Glasshouses (ha)

Spain

Ex. Yugoslavia

Tunisia

1965 -

650 1240

1977

- 250

- 50

1985 20

1500 2050 500 1370 200

70 -

1965

350 -

180 1180

2

269

1977 ' 400 5800

2300 17000

2000

-

-

- 2617

1985 1200 15000 6160 4000 17500 600 4600 200 1050 3 120

1994 2600 28350 6465 9100

24300 5040 10800 2500 1425 3975

- - L - 170 200 Adapted fiom Grafiadellis 1987; Castilla 1995.

The most plastic in long life polyethylene films and only the films and mainly the

films found big applications. (Nisen et al, 1990).

vol. 31 18


plastic panels made of l m to 14mm thick, the of 0.9- thick and the

6mm thick used.

TYPES OF

to the local climatic conditions, the the the customs, in the of developed (Nisen et al 1990; El-Aidy 1991; 1985; 1992). of the saddle

the side walls, the side walls and the book 1986; Nisen et al 1990;

1984; Zabeltitz 1990).

the of the single span the side walls (fig. 1 and fig.2).

_. . . . . . . .

A single span round arched','greenhouse (FAO booklet, greenhouses in Syria). .. ..

. . . . - . . . . . , . . . . . . . . ..-. . .

i . . .I /

. .

. . . . . .

. . - . .. . I .- .. '

. . . . . . . . , , . . -? - . - . . .

. .

. . . . . .

Fig. 2 A round arched greenhouse with vertical sidewalls (FAO ; greenhouses in . . . .

. . . . . . .

vol. 31 19


in the greenhouse types made wood steel the side walls mainly used (fig.3, fig.4).

.Fig. 3':A ,sddle'mof greenhouse type rnade.fri3m'wood and .steel pipes Crete. (FAO . .

. .

. . . . .

. . . .

.Fig. 4 A.saddk greenhouse. . . . type used in:Sic&'(FAQ book). . . . . .

in Spain the linked one to at film is sandwiched

vol. 31 20


(fig.5). The last the

Figure 5. Parral type greenhouse in Almeria, Spain (FAO book)

- type the plastic above and below the wooden sticks in the is mainly used (fig.6). this type of the to be single span to to multispan.

Figure 6. Wooden greenhouse type in Portugal (FAO book)

of been developed, some of which of saddle (fig.7) of shed (fig.8)

ventilation (fig. 9).

Cahiers VOL 31 21


. '. . . . . . .. . . . . .

. . . ... .. .- _ " ... - - . . .

' 1 . . , . . . . , ...

Figure 7. A saddle roof type greenhouse (FAO book)

. . . . . . . . . .

. . .

. .

. . ..

Fig. 9. A type of greenhouse with roiling - up ridge ventilation in (FAO booklet, greenhouses in Cyprus).

Cahiers Options 31 22


ln the most of the the the 1 O).

Fig. 10 Pointed arched type greenhouse in (FAO booklet).

The main technical problems, which the structures of regions face, are:

The biggest enemy of the plastic the the wind. The huge in the wind

speeds something exceed the 40-45ds (144-162 that in some cases the winds al Finn 1992).

to the of been designed to 3 4 d s of 25kg/m2 and a plant weight of 20kg/m2 (Vadiou the

3 4 d s wind speeds, the obliged to take such as the use of to the to the

of the to to of al et al 1978; FAO book 1987).

A second big enemy of the is the snow load. to withstand a load of

25kg/m2. of the snow falls usually exceed the take

Finn sensitive to 1987). to avoid the damages of the

the big snow loads, the the top of the 1992).

in of mainly the not taking the

to

Cahiers Options vot. 31 23


b) The shape and the slop of the roof of the greenhouses. that the the the

to than the (JaEin 1990; al 1995; FAO in the

the the low of in the et al,

1990).

As as the the is well known that it effects the off of the the movement inside the the

FAO slops such

28" as minimums.

c) The dimensions and the sizes of the greenhouses. done by institutions and the the that the

side walls of the the ventilation, the mechanization of the of the the development of the tall (FAO 1987; Nisen et al to the

the height of the side walls of the at least 260

in side walls, too many in m3/m2 (Nisen et al, 1990).

many cases the too (Nisen et al, 1990).

d) the the light is in the of

the the the the size of the the of the the shape of the

the the the and the small slops. (Castilla 1994; FAO 1987; Jafiin

e) Ventilation. Almost all the adequate ventilation. The

the the that in the the between the opening and the should be at least 22-25% and that the multispan which

et al, 1984). also found some

f) The plastic films.

the of the scientists and of the that the of the polyethylene films the at plastics should not be to be changed, should have as as optical be et al 1990; Zabeltitz 1990).

g) The collection of the rainwater by the greenhouse gutters. that the is of bed quality, it is to mix it with the

collected by the I

Cahiers Options 31 24


h) The cost of the greenhouse structures. that in the

not always the economical ones applications of the and its effect on the cost of the

has et al, 1995).

NEW OF

to the in the 7900 the the table 2 it can be

that the tendency is the

Today the as high as that the to

the of the of the

etc.

As as the shapes of the the to

the to

in the also to on the to the to minimize the to shapes etc.

the ventilation the tendency is of openings even 40% and mechanization mainly of the the side ones. although has is to be adapted.

the of gaining the antifogging due to the to some technical

also found some applications only

The collection and the use of the to high cost has applications.

pushed to the the

Arbel, A., Segal, Yekutieli, O. and Zamir, 1990. 281: 167-174.

Bailey, B.J., 1985. of

Brun, and J., 1985. adapted to conditions. Acta 170:37-46.

31 25


Castilla, N. J., 1995. in the 107:13-20.

Castilla, 1994. the

and Grafiadellis, 1992. A study of of of the the field

Grailadellis, 1996. in the of the XXV, th annual meeting of

El-Aidy, F., 1991. to the climatic conditions of Egypt. 92(4):33-40.

FAO book., 1986. in the FAO, ppl-26.

FAO book, 1987. the in of FAO, ppl-32.

Grafiadellis, 1985. A study of

Grafiadellis, 1986. of a passive 191~245-252.

Grafiadellis, 1987. 328.

Goldsberry., 1978.

Jaffrin, A. and Urban, 1990. Optimisation of

The influence of the

Nisen, A., P.F., O., U. and Baudoin, W.O., 1990. cultivation-in

the

Preben, and Finn B., 1992. FAO Technical

Sadao, N., 1995. Japan. the 108 (4):3-12.

Cahiers Options vol. 31


Sirjacobs 1984. Use of new types of plastic tunnels for Acta 15493-100.

Triki, J., Verlodt, and Baeten, S., 1984. la sous Acta 154: 241-248.

Tmuramaai, and GdadeW, 1995.

Vassiliou, N., 1992. companies points of view. FAO 1 14-121.

Waaijenberg, 1992. by wind, snow FAO

Zabeltitz, C.V., 1984. film Acta 154: 305-3 14.

Zabeltitz, C.V., 1990. function of 263~257-374.

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