Research Program Area: Ecosystem & Multimedia Effects
Experiments were conducted for two years (1983 and 1984) to determine the impact of ambient oxidants and realistic concentrations of S02, both alone and in combination on two varieties of Acala-type cotton. Cotton is by far the most important field crop grown in the San Joaquin Valley, accounting for returns annually of over 1.5 billion dollars to the economy of the region.
Acala SJ-2, the most commonly grown variety in the San Joaquin Valley, accounting for 79% of the planted acreage, and SJC-1, a promising new variety, were planted in 12 foot square plots enclosed by open top, plastic covered, force ventilated chambers. Anhydrous S02 in amounts necessary to produce con-centrations of .05 and .10 ppm S02 by volume was metered into the air streams ahead of the blowers six hours per day four days per week during the growing season (June through September). The treatments used in these experiments were as follows:
1. Filtered air chambers (all air passed through activated carbon filters)
2. Ambient air chambers (no filters)
3. Filtered air plus .05 ppm S02 (six hours per day, four days per week)
4. Filtered air plus .10 ppm S02 (six hours per day, four days per week)
5. Ambient air plus .05 ppm S02 (six hours per day, four days per week)
6. Ambient air plus .10 ppm S02 (six hours per day, four days per week)
7. Outside plots (same size but no chamber walls).
Care was taken to keep other growing conditions as nearly alike in all chambers as possible. Temperature, humidity, light intensity and soil fertility were uniform from plot to plot.
For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753
Stay involved, sign up with CARB's Research Email Distribution List