Diseases and Management of Crops under Protected Cultivation

(Diseases and Management of Crops under Protected Cultivation)
achieve uniformity of temperature distribution. Therefore, placement of heating units and
the type of distribution system to be selected are important.
Heating Systems Based on Non-Conventional Energy Sources
• A number of active solar heating have been developed for greenhouse during the last two
decades in order to feduce the dependence of greenhouse industry on conventional fuels.
• The normal components of a solar heating system are :solar collector, heat transfer
medium, heat exchanger, and heat storage.
• Biogas, generated from agricultural wastes/residues, can also be used for greenhouse
heating.
Design of Passive Solar Greenhouse
A passive solar greenhouse is one which not only attempts to capture maximum solar
energy but also minimizes the unwanted thermal exchange between the greenhouse and the
surroundings in order to maintain desirable temperatures, The following points summarize the
useful results so far:
1. A greenhouse should be oriented east-west.
2. The north side of a greenhouse structure should be thermally, insulated.
3. The north side of a greenhouse facing the crop should be covered with a reflective surface so
that the sunlight incident on it from the south side is reflected on to the crops.
Water harvesting from the GH
REFERENCES
• NHB. 2005. 2005. National Horticulture Board, Indian Horticulture Data Base 2005.pp361.
• Annonymous. 2008. Annual Report: 2007-08. Precision farming Development Centre, G. B. Pant
University of Agriculture and Technology, Pantnagar, Uttarakhand, India, pp 105.
• Singh, B. 1998. Vegetable production under protected condition: Problems and Prospects.
Indian Society of Vegetable Science Souvenir: Silver Jubilee, National Symposium
Dec.12 14, 1998, Varanasi, U.P. India, pp 90.
- 64 -