Diseases and Management of Crops under Protected Cultivation

(Diseases and Management of Crops under Protected Cultivation)
rate is directly proportional to CO2 concentration upto 2400 ppm. Hence supplementary
application of CO2 will boost plant productivity inside the greenhouse. Under Hilly region
situation., appropriate air circulation is better and economic means to prevent undesirable
lowering of CO2 while for conservation of CO2 produced at night, a tight closed greenhouse is pre
requisite.
e) Soil
Soil serves as growth medium for plants. Sandy loam soil is the best choice. It should be
supplemented with well rotten FYM, compost or biofertilizers. Inorganic fertilizers need to be used
as per recommendations. Continuous cultivation inside the greenhouse may give rise to
pathogens. To destroy pathogens pasteurization of soil is recommended (steam aeration) before
every crop and soil replacement is recommenced after every 3 years. For steam aeration
temperature of 60C for 30 minute is good enough to accomplish the task. Chemical fumigation
can also be used but steam is the best as it is not selective thus attacking all sort of pathogens.
2.4 Benefits of Greenhouses
Major benefits of greenhouse in are given below:-
i. Cultivation of crops during off season when it is not possible to grow in open fields.
ii. Tropical vegetables like cucurbits, capsicum, brinjal, okra etc are rare in hilly region but
these crops can be grown in greenhouse.
iii. Greenhouse provides an excellent opportunity to produce quality crops for export.
iv. Raising nursery earlier and advancing the availability is also possible by use of
greenhouse.
v. Productivity in greenhouse is increased manifold in comparison to open field.
vi. Conservation of valuable planting materials and its cultivation is also possible under
greenhouse.
vii. Greenhouse can also be used for growing of flower plants, strawberries, grapes and
propagation of quality fruit plants.
viii. Insect pest and weed management is easier in greenhouse than open.
ix. Greenhouse conserve the moisture. Hence frequency of watering to plants get reduced.
x. Greenhouse is ideally suited for Indian farmers having small holdings.
xi. Productivity per unit area and time can be increased by adopting suitable crop sequences.
3. Infrastructure of Greenhouse
3.1 Types of Glazing Materials
3.1.1 Glass
Glass has been the preferred covering material for greenhouse world wide becuase of its
light transmissivity characteristics. Transmissivity of 40-50 years old glass differs a little from that
of new glass. Temperature retension in glasshouse is pretty good. However, high installation cost
is major limitation. Moreover, transportation of materials and frequent damage of glasses due to
- 177 -