Lesson 1: Rainfall and plant growth

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Module 4 Weather and Plant Growth
Virtual Academy for the Semi Arid Tropics
Modules
Lessons

Lesson 1 Rainfall and plant growth
After completing this Lesson, you will be able
to answer 1. Why rainfall is important for
crops? 2. What is the role of water in plant
growth? 3. How rainfall is important for
crops? 4. What happens if rainfall is low? 5.
How excess rainfall affects plant growth? 6.
How information about rainfall useful in
crop production?
Course on Crop-Weather Relationships
2
Lesson 1 Rainfall and plant growth

• Why rainfall is important for crop plants?
• Plants use a tremendous amount of water.
• Example Water requirement for rice is 300 to
  950 mm, for sorghum it is 300 to 650 mm.
• Rains, to a major extent, provide this water,
  through the soil, for the development and growth
  of plants.
• Rainfall is the first source of water. Irrigation
  can supplement rainfall to supply crop water
  needs.

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Module 4 Weather and Plant Growth
Virtual Academy for the Semi Arid Tropics
Modules
Lessons

Lesson 1 Rainfall and plant growth

• Why rainfall is important for crop plants?
• Importance of water for plants
• Need for the physiological processes to complete
  plant life cycle i.e. seed to seed
• A primary component in photosynthesis and
  respiration
• Responsible for turgor pressure in cells (Like
  air in an inflated balloon, water is responsible
  for the fullness and firmness of plant tissue).
• Maintains temperature of plant body

Course on Crop-Weather Relationships
4
Module 4 Weather and Plant Growth
Virtual Academy for the Semi Arid Tropics
Modules
Lessons

Lesson 1 Rainfall and plant growth

• Why rainfall is important for crop plants?
• Importance of water for plants
• Helps in the uptake of nutrients from soil
• A solvent for minerals and carbohydrates moving
  through the plant
• Serves as a medium through which nutrients and
  other solutes move in the plants.
• Thus, water from rainfall is vital for plant
  growth.

Course on Crop-Weather Relationships
5
Lesson 1 Rainfall and plant growth

• How rainfall is important for crop plants?
• Less rain or breaks in monsoon rainfall results
  in moderate to severe moisture stress.
• Such moisture stress affects
• Root and shoot development
• Flowering
• Pollination and fertilization
• Grain filling
• Crop yields.
• Thus, water from rainfall is vital for plant
  growth.

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Lesson 1 Rainfall and plant growth

• How rainfall is important for crop plants?
• Equally damaging is excess rainfall
• Causes flooding of fields
• water stagnation affects the growth processes
• Continuous rains during flowering time affect
• Fertilization
• Grain formation and filling
• Favors plant diseases and pests
• Interferes with many farming operations like
• seedbed preparation,
• sowing,
• harvesting, threshing, and processing of crops
• Result in low crop yields.

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Lesson 1 Rainfall and plant growth

• Information on probable dates of commencement and
  end of the rainy season, and the duration of
  intermittent dry and wet spells can be very
  useful for planning
• cropping systems
• agricultural operations
• seedbed preparation,
• manuring,
• sowing/ transplanting,
• weeding and interculture,
• harvesting, threshing, drying etc.
• The above information also helps in optimum
  utilization of labor, fertilizers, and
  pesticides.

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Module 4 Weather and Plant Growth
Virtual Academy for the Semi Arid Tropics
Modules
Lessons

This concludes Lesson 1- Rainfall and plant
growth - in this Module.
Next Lesson is about Relative humidity and plant
growth. Click Lessons button to select Lesson
2
Course on Crop-Weather Relationships