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OPTIMISATION OF OUT-OF-SEASON CROPPING IN MILD WINTER GREENHOUSES BY CROP DIVERSIFICATION, QUALITY IMPROVEMENT AND BETTER USE OF PRODUCTION MEANS

Objective


Lightweight Medterranean shelters make production possible before the normal season for field crops. Research has led in 3 directions:

Improving structures:
The slope of the roof and orientation of greenhouse structure have been defined for optimal climatic conditions.
Progress has been made in development of the hydrotunnel to reduce the danger from spring frost. The use of large transparent plastic tubes filled with water and laid on the ground to either side of the plants to return at night the heat accumulated during the day is now widespread in Greece, and is providing good results.
The use of solarization to control soil fatigue seems to be an effective but temporary way of keeping down nematode populations.

Improvement of plant material:
The varieties grown in Mediterranean shelters have to produce regularly in an unfavourable environment (cold nights, very variable humidity). Greater use is being made of parthenocaropic varieties which can be harvested without fertilization. A good parthenocarpic genitor has been found.

Alternative crops:
Shelters require to be used to grow other crops, either in the event of glut or during the normal growth period. Many plant species have been tried and some are of great interest.

The project was set up to investigate methods of improving the quality and production of crops grown in plastic greenhouses in southern areas of Europe. Data on air exchange rates was recorded in traditional and improved greenhouses with natural ventilation. Forced ventilation was examined as a means of reducing fungal risk. Passive solar heating systems were tested for cold protection and heating of greenhouses in mild winter Mediterranean areas and an economic analysis made. The behaviour of plants under various stress conditions was evaluated and models for transpiration and photosynthesis have been prepared. Soilless culture of tomato was used to determine the actual uptake of the main elements (nitrogen, phosphorus, potassium, calcium, magnesium) and showed that reduction of fertilizer by 50% is possible, without change in yield. Several substrates were evaluated for physical effects and productivity. New species of ornamental plants and vegetables are being tested in the greenhouse.
The total area of plastic greenhouses in southern EC is estimated at 50 000 ha. Presently this activity is facing two major problems, the need for a crop diversification, and the low quality of the products in relation to environmental stress, which constrains quality and production efficiency.

The project tackles these problems through integrated multidisciplinary actions :
I. Greenhouse engineering and ecophysiology for the control and characterization of stress conditions and effects (climatic, water, osmotic) by means of passive and dynamic techniques of ventilation, shading, cold protection.
II. Breeding to select and evaluate plant material of tomato for low temperature fruit-setting and osmotic stress resistance.
III. Growing techniques for new introduction of crops and cultivars.

Coordinator

Instituto Nacional de Investigaciones Agrarias
Address
Apartado Official
46113 Valencia
Spain

Participants (15)

Agricultural Research Center for Northern Greece
Greece
Address
Elliniki Georcgiki Scholi
54110 Thessaloniki
Centre National du Machinisme Agricole, du Génie Rural, des Eaux et des Forêts (CEMAGREF)
France
Address
Domaine De Lavalette
34033 Montpellier
Centro de Investigacion y Desarrollo Agrario de Granada-Direccion General de Investigacion y Extension Agraria
Spain
Address
Camino De Purchil 2027
18004 Granada
Centro de Investigacion y Tecnologia Agrarias-Consejeria de Agricultura y Pesca del Gobierno de Canarias
Spain
Address
Apartado Correos 60
38080 La Laguna
Comité National Interprofessionnel de l'Horticulture
France
Address
Cd 2009 7630 La Baronne
06610 La Gaude
Consejeria de Agricultura y Pesca
Spain
Address
Apartado Oficial
46113 Valencia
Consejo Superior Investigaciones Cientificas
Spain
Address
Estation Experimental La Mayora
29750 Algarrobo Costa
Direccao Regional de Agricultura do Algarve
Portugal
Address
Apartado -Patacao 282
8000 Faro
ISTITUTO SPERIMENTALE PER L'ORTICOLTURA DEL MINISTERO DELLE RISORSE AGRICOLE, ALIMENTARI E FORESTALI
Italy
Address
Via Cavalleggeri 25
84098 Pontecagnano
Institut National de la Recherche Agronomique (INRA)
France
Address
Domaine Saint-paul
84143 Montfavet
Institut de Recerca i Tecnologia Agroalimentaries
Spain
Address
Passeig De Gracia 44
08007 Barcelona
Instituto Nacional de Investigacao Agraria
Portugal
Address
Quinta Do Marques
2780 Oeiras
Instituto Superior de Agronomia
Portugal
Address
Tapada Da Ajura
1300 Lisboa
UNIVERSITÀ DEGLI STUDI DELLA TUSCIA
Italy
Address
Via S. Camillo De Lellis
01100 Viterbo
Università degli Studi di Catania
Italy
Address
Via Valdisavoia 5
95123 Catania