Effect of Far Red Light on Drought Resistance of Cotton

The resistance of cotton (Gossypium hirsutum L.) to droughtstress was increased when plants, grown under a 9 h light period,received a 30 min far red (FR) illumination at the beginningof the dark period. With the addition of FR light, the plantsdisplayed higher stomatal resistance and lower rate of transpiration.Therefore, with the addition of FR, the plants remained at higherleaf turgor potential during the period of drought stress whencompared to plants stressed without the FR illumination. ThusFR illumination improved the water economy of the plants. (Received April 20, 1982; Accepted August 30, 1982)