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Most people know that plants need warm temperatures and light to survive. However, excess light combined with high temperatures can result in disruptions to plant systems, particularly photosynthesis.

Crops grown in open fields fight adverse environmental conditions. They receive more light than needed for photosynthesis, and are subject to a range of temperatures. With increasing temperatures, the conversion of light to sugar is impaired. This phenomenon is known as photoinhibition.

The relationship between temperature and light intensity in contributing to photoinhibition is diagramed below.

Temperature and Light on Photosynthesis

CROP STRESS: Beyond Basics

At higher temperatures, photoinhibition begins at lower light intensities. Photoinhibition prevents photosynthesis, meaning:

Fewer carbohydrates available for growth of stems, roots, or to provide energy to developing fruits.

Light absorbed by leaf produces free radicals, which cause damage to membranes, chloroplasts and cells.

Plants must now use remaining energy to repair damage.