Question

If plant uses 6 percent of PAR, then percentage of I .S .R. plant use is _____.

• A. 6%
• B. 3%
• C. 12%
• D. 24%

Answer 1

Answer: (C)

12%

• Photosynthetically Active Radiation (PAR) can be defined as the amount of light available for the plants to carry out photosynthesis.
• The light in the range of 400 to 700-nanometer wavelength is usually absorbed by the plants.
• PAR can vary seasonally and also depends on the latitude and time of day.
• The amount of PAR available to plants can be reduced by cloud cover, air pollution and shades provided by trees and buildings.
• ISR is also known as the incident solar radiation.
  
• Out of total ISR, only 50 per cent of it is PAR.
• If PAR is 6% then, ISR is 12%.
• So, the correct answer is '12%'.