A SCOPE ON GREENHOUSES AROUND THE WORLD
- There are more than 55 countries now in the world where cultivation of crops is undertaken on a commercial scale under cover and it is continuously growing at a fast rate internationally.
- The United States of America has a total area of about 15,000 ha under greenhouses mostly used for floriculture with a turnover of more than 3.4 billion US $ per annum and the area under greenhouses is expected to go up considerably, if the cost of transportation of vegetables from neighbouring countries continues to rise.
- Spain has been estimated to be around 28,000 ha and Italy 19,500 ha used mostly for growing vegetable crops like watermelon, capsicum, strawberries, beans, cucumbers and tomatoes. In Spain simple tunnel type greenhouses are generally used without any elaborate environmental control equipment mostly using UV stabilized polyethylene film as cladding material.
- In Canada the greenhouse industry caters both to the flower and off-season vegetable markets. The main vegetable crops grown in Canadian greenhouses are tomato, cucumbers and capsicum. Hydroponically grown greenhouse vegetables in Canada find greater preference with the consumers and could be priced as much as twice the regular greenhouse produce.
- The Netherlands is the traditional exporter of greenhouse grown flowers and vegetables all over the world. With about 89,600 ha under cover, the Dutch greenhouse industry is probably the most advanced in the world. Dutch greenhouse industry however relies heavily on glass framed greenhouses, in order to cope up with very cloudy conditions prevalent all the year round. A very strong research and development component has kept the Dutch industry in the forefront.
- The development of greenhouses in Gulf countries is primarily due to the extremity in the prevailing climatic conditions. Israel is the largest exporter of cut flowers and has wide range of crops under greenhouses (18,000 ha) and Turkey has an area of 12,000 ha under cover for cultivation of cut flowers and vegetables.
- In Saudi Arabia cucumbers and tomatoes are the most important crops contributing more than 94% of the total production. The most common cooling method employed in these areas is evaporative cooling.
- Egypt has about 1400 ha greenhouses consisting mainly of plastic covered tunnel type structures. Arrangements for natural ventilation are made for regulation of temperature and humidity conditions. The main crops grown in these greenhouses are tomatoes, cucumbers, peppers, melons and nursery plant material.
- In Asia, China and Japan are the largest users of greenhouses. The development of greenhouse technology in China has been faster than in any other country in the world. With a modest beginning in late seventies, the area under greenhouses in China has increased to 51, 000 ha. Out of this 11,000 ha is under fruits like grapes, cherry, Japanese persimmon, fig, loquat, lemon and mango. The majority of greenhouses use local materials for the frame and flexible plastic films for glazing. Most of the greenhouses in China are reported to be unheated and the use of straw mats to improve the heat retention characteristics.
- Japan has more than 40,000 ha under greenhouse cultivation of which nearly 7500 ha is devoted to only fruit orchards. Greenhouses in Japan are used to grow a wide range of vegetable and flowers with a considerable share of vegetable demand being met from greenhouse production.
- Even a country like South Korea has more than 21,000 ha under greenhouse for the production of flowers and fruits. Thus, greenhouses permit crop production in areas where winters are severe and extremely cold such as Canada and Russia. It also permits production in areas where summers are extremely intolerable as in Israel, United Arab Emirates, Kuwait.
- In the Philippines greenhouses make it possible to grow crops despite excessive rains. Thus in essence greenhouse cultivation is being practiced and possible in all type of climatic conditions.
- While greenhouses have existed for more than one and a half centuries in various parts of the world, in India the use of greenhouse technology started only during 1980’s and it was mainly used for research activities. This may be because the emphasis had been on achieving self-sufficiency in food grain production. However, in recent years in view of the globalization of international markets and shortages of food a tremendous boost is given to export of the agricultural produce in India, this has now created a spurt in the demand for greenhouse technology.
- If India wants to emerge as an economic power in the world, agricultural productivity should equal those countries, which are currently rated as economic power of the world. The greenhouse system may be one key element to sustain food for growing Indian population/economy.
DEVELOPMENT OF GREENHOUSE TECHNOLOGY IN INDIA
- The National Committee on the use of Plastics in Agriculture (NCPA-1982) has recommended location specific trials of greenhouse technology for adoption in various regions of the country. Greenhouses are being built in the Ladakh region for extending the growing season of vegetables from 3 to 8 months. In the North-East, greenhouses are being constructed essentially as rain shelters to permit off-season vegetable production. In the Northern plains, seedlings of vegetables and flowers are being raised in the greenhouses either for capturing the early markets or to improve the quality of the seedlings. Propagation of difficult-to-root tree species has also been found to be very encouraging. Several commercial floriculture ventures are coming up in Maharashtra, Tamil Nadu and Karnataka states to meet the demands of both domestic and export markets.
- The commercial utilization of greenhouses started from 1988 onwards and now with the introduction of Government’s liberalization policies and developmental initiatives, several corporate houses have entered to set up 100% export oriented units. In just four years, since implementation of the new policies in 1991, 103 projects with foreign investment of more than Rs.80 crores have been approved to be set up in the country at an estimated cost of more than Rs.1000 crores around Pune, Bangalore, Hyderabad and Delhi. Thus the area under climatically controlled greenhouses of these projects is estimated to be around 300 ha. Out of which many have already commenced exports and have received very encouraging results in terms of the acceptance of the quality in major markets abroad and the price obtained.