this ppt describes basics of greenhouse technology.

1. GREEN HOUSE
TECHNOLOGY
Dr. S. Mohapatra

2. • Greenhouse technology, also known as protected
cultivation or controlled environment agriculture,
involves creating an artificial environment to cultivate
crops under controlled conditions.
• This technology has revolutionized modern agriculture
by extending the growing season, optimizing crop
growth, and improving overall productivity.
• Greenhouses provide a sheltered space where
temperature, humidity, light, and other environmental
factors can be managed to create ideal conditions for
plant growth, irrespective of external weather
conditions.

3. 1. Purpose of Greenhouses: Greenhouses are used to create a
microclimate that suits the specific requirements of different
plants. They shield crops from extreme weather conditions
such as cold, heat, wind, and excessive rain. This controlled
environment allows for year-round cultivation of crops that
might not thrive in the local climate.
2. Structure and Design: Greenhouses are typically constructed
using materials like glass or plastic. The structure includes
walls and roofs that allow sunlight to enter while trapping heat.
This design creates a warmer and more humid environment
inside, which is particularly beneficial for crops like
vegetables, flowers, and ornamental plants.
3. Temperature Regulation: Greenhouses have mechanisms to
control temperature. Ventilation systems, shade nets, and
cooling pads help prevent overheating during hot periods,
while heating systems maintain warmth during colder seasons.

4. 4. Humidity Management: In a greenhouse, humidity is
maintained at optimal levels. This is essential for proper plant
growth, as some plants require higher humidity than what's
available in the natural environment.
5. Light Management: Greenhouse technology allows for the
regulation of light. Shade nets or shading systems can be adjusted
to control the amount of sunlight reaching the plants, preventing
excessive exposure that could cause stress or sunburn.
6. Water Management: Greenhouses often have irrigation
systems that provide water directly to the plant roots. This ensures
efficient water usage and reduces the risk of diseases caused by
water splashing onto the plants.
7. Pest and Disease Control: The controlled environment of a
greenhouse makes it easier to monitor and manage pests and
diseases. Physical barriers like screens or nets can prevent pests
from entering the structure, reducing the need for chemical
pesticides.

5. 8. Crop Diversity: Greenhouses enable the cultivation of a wide
range of crops, regardless of the native climate. This diversity can
include vegetables, fruits, flowers, herbs, and even exotic or
delicate plants.
9. Enhanced Productivity: Because of the controlled conditions,
plants in greenhouses tend to grow faster and yield higher quality
produce. This can lead to increased profitability for farmers.
10. Sustainable Agriculture: Greenhouses promote sustainable
agriculture by reducing the need for excessive water usage,
preventing soil erosion, and minimizing the use of chemical
inputs.
11. Research and Experimentation: Greenhouses also serve as
platforms for agricultural research and experimentation. Scientists
can study the effects of different environmental conditions on
plant growth and develop new techniques for improving crop
yield and quality.

6. Greenhouses can be classified based on various factors.
1. Based on Covering Material:
• Glass Greenhouses
• Plastic Film Greenhouses
• Polycarbonate Greenhouses
• Shade Houses
• Insect-Proof Screen Houses
2. Based on Shape and Structur:
• Traditional Greenhouses
• Hoop Houses or High Tunnels
• Gothic Arch Greenhouses
• Quonset Greenhouses
• A-Frame Greenhouses

7. 3. Based on Cultural Systems or Growing Systems
• Hydroponic Greenhouse
• Aquaponic Greenhouse
• Soil-Based Greenhouse
• Vertical Farming Greenhouse
4. Based on Purpose and Function
• Cold Frames
• Warm Houses
• Cool Houses
• Research or Experimental Greenhouses
• Commercial Greenhouses
5. Based on Technology and Control
• High-Tech or Controlled Environment Greenhouses
• Low-Tech Greenhouses

8. 6. Based on Crop Requirements
• Orchid Houses
• Vegetable Greenhouses
• Flower Greenhouses
7. Based on Scale
• Small-Scale or Backyard Greenhouses
• Large-Scale Commercial Greenhouses

11. Step 1: The Sunlight is Trapped
In order to trap the light, greenhouses use materials that are made
mostly from transparent or translucent materials, like glass or
plastic polycarbonate sheets. The trapped light provides the plants
with enough access to sunlight.
Step 2: Sunlight is Converted into Energy
The plants and other elements in the greenhouse absorb the light
and convert it to heat. Dark elements tend to absorb more energy
and increase the greenhouse temperature. This is why the black
surface gets really hot in the summer because it absorbs a lot of
heat.
Step 3: The Heat Gets Trapped
Trapping the heat is one of the primary functions of the greenhouse
called the “Greenhouse effect”. When the light is converted into
infrared energy (heat), it takes a different form (wavelength). The
transformation of the energy into a different wavelength makes it
difficult for the heat to escape the greenhouse’s walls easily.

12. Step 4: Warming the Greenhouse
When the heat is trapped inside the greenhouse, it warms up the air
inside. The warm air causes the temperature to increase inside the
greenhouse. Since the greenhouse is relatively air-tight, the warmer
air stays inside, and the temperature sustains for a longer period of
time.
Step 5: Supporting Photosynthesis
Sufficient light and enough warm temperatures provide ample
conditions for the plants to grow. A sufficient amount of light and
temperature allows photosynthesis to occur. Photosynthesis is the
process by which plants synthesize nutrients (mainly sugar) from
carbon dioxide from the air, energy from the sunlight, and water,
which the plant then uses as food. Photosynthesis generally involves
the green pigment in the plants called “chlorophyll” and produces
oxygen as a by-product.