Plants Sip Instead of Gulp, to Yield More
By Dennis Senft
January 15, 1997
Cotton plants in Southern California can produce more cotton fiber if they
take smaller, more frequent sips of the same amount of irrigation water they
would normally get during July.
Scientists with USDAs
Agricultural Research Service developed
and tested the new approach in Californias Imperial Valley.
In their three-year test, they applied just over 1-1/2 inches of water every
five days during July, resulting in increased cotton yields by five to 11
percent. The new technique used no more water than traditional July regimens of
three inches every 10 days, or 5 inches every 15 days.
Some growers and others have believed the traditional regimen is necessary
to flush away salt that can damage crops if it accumulates in the soil. But the
scientists found that no salt accumulated in the top 6 inches of soil during
Why irrigate more often in July? The scientists say July is the peak time
when cotton buds open up in the valley, and stresses such as inadequate water
can strike yields especially hard.
The scientists found that small, frequent irrigations keep plants in peak
condition with lower leaf temperatures, high leaf moisture content and higher
leaf transpiration rate.
Scientific contact: Chang Chi Chu, USDA-ARS Irrigated Desert Research
Station, Brawley, Calif., phone (619) 344-4184