Diseases and Management of Crops under Protected Cultivation

(Diseases and Management of Crops under Protected Cultivation)
with respect to crop are made on the sheets for holding seedlings. Roots of the seedlings remain
in touch with the circulating nutrient solution nutrient solution. An aerator is also needed for supply
of oxygen to roots. 10-12 hour nutrient solution run is sufficient for optimum absorbtion.
ii) Wick Technique
It doesn’t require any pump. Plant roots get nutrients through wick from the reservoir.
iii) Nutrient Film Technique
The NFT systems provide a constant film of water and nutrients along the bottom of a
channel. In effect, part of the roots grow down in the water/ nutrients and parts of the roots above
the water line getting fresh air and oxygen
iv) Flood and Drain System
It is the most versatile. Each time the water floods from the lower reservoir into the upper
growing tray, the roots are bathed in the fresh nutrients. When the nutrient drains back to the
reservoir, fresh air is drawn through the root system refreshing oxygen to the roots.
v) Aeroponics
It is the misting of plant roots in air. It was developed in the last century at the University of
Pia in Italy by Dr. Franco Massantini. It has been proven and refined for decades and is used by
scientists around the world, including NASA (National Aeronautics and Space Administration).
Aeroponics uses 65% less water than hydroponics. NASA also concluded that aeroponically
grown plants requires ¼ the nutrient input compared to hydroponics. Unlike hydroponically grown
plants, aeroponically grown plants will not suffer transplant shock when transplanted to soil, and
offers growers the ability to reduce the spread of disease and pathogens. Aeroponics is also
widely used in laboratory studies of plant physiology and plant pathology. Aeroponic techniques
have been given special attention from NASA since a mist is easier to handle than a liquid in a
zero gravity environment.
Aeroponics plants
• Receive their required daily nutrients
• They avoid contact with soil borne pests and fungus
• They grow up to 50% faster
Medium culture
It requires various substrates as sand,gravel,peat,perlite,vermiculite,rockwool.Besides the
above techniques for growing plants under hydroponic system an important way of integrating
aquaculture and fish culture also exists called as Aquaponics
Aquaponics
It can best be defined as a combination of aquaculture and hydroponics. In aquaponics the
fish and plants are produced in a single integrated system, where the fish waste provides a food
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