Which greenhouse is the best? This question is easier to ask than to answer. The perfect greenhouse depends on the local climate, the price the grower hopes to fetch for the product, the investment, the local regulations, etcetera. Wageningen UR Greenhouse Horticulture Greenhouse Horticulture has developed a method that accounts objectively for several of these factors. A number of factors have to be considered before the ‘dream greenhouse’ emerges.
The Dutch greenhouse builders are missing opportunities in the international market for greenhouse construction. This is mainly caused by the strong focus on glass greenhouses. Glass may still be the most versatile cover material, but the payback period of a glasshouse often exceeds the typical horizon of many investors, which is five years. Construction, however, is not the only factor. Knowledge and skills of the grower and available labour are even more determining factors for profitability than greenhouse design, materials and fittings. Knowledge and experience of the grower are critical and becoming a good grower takes time. According to Peter Stradiot of Innogreen, training takes at least three years.
During his PhD at Wageningen UR Bram Vanthoor developed a mathematical method for designing greenhouses that are better adapted to local conditions. This method delivers a greenhouse that yields maximum financial result while taking into account local climatic and economic conditions. The method has been tested for the Netherlands and for Spain and has proven to offer perspectives for optimisation of greenhouse construction worldwide. The method has primarily been developed for tomato, but adaptation for other crops is possible. Bram Vanthoor is now living and working in Mexico as business developer for HortiMaX where the acquired knowledge is used for the development of greenhouses that are better suited to the local conditions.
Locally adapted intensive horticulture can help to increase yields. This will contribute to meet the world food challenge. Wageningen UR has made calculations which show that greenhouse-produced tomatoes can use twenty times less farming soil and fresh water. The technology content of the growing system does help to increase resource use efficiency but this needs to be related to the financial and technical ability of the grower.
Local for local
The global trend to ‘local for local’ emphasises the need to produce high-quality greenhouse vegetables with the least possible environmental impact. This requires the development of greenhouses that are adapted to local socio-economic and climatic conditions and that are operated by well-trained growers.