COLLEGE OF AGRICULTURE AND LIFE SCIENCES
	Fitz Booker USDA-ARS Plant Physiologist and Associate Professor of Crop Science	CROP SCIENCE PERSONNEL
	USDA Facility (Non-NCSU Bldg.) 14,CB 7631 USDA-ARS Plant Science Research Unit 3908 Inwood Road Raleigh, NC 27603	CURRICULUM VITAE
	Phone: (919) 515-9495 FAX: (919) 515-3593 NCSU Personal Web Page fbooker@mindspring.com

Dr. Booker’s graduate training was in plant physiological ecology. As a member of the Plant Science Research Unit he has investigated the effects of UV-B radiation, elevated atmospheric CO₂ and pollutant ozone (O₃) on soybean, cotton and loblolly pine growth and secondary metabolism. Dr. Booker is currently conducting field studies on the individual and combined effects of elevated atmospheric CO₂ and O₃ on gas-exchange, growth, and decomposition of soybean and peanut.

Current Projects in Lab

Current projects (see Fig. 1) involve a 5-year study that examines the effects of elevated CO₂ and ozone on crop physiology and soil C & N dynamics in a no-till, soybean-wheat cropping system using open-top field chambers. We are also conducting experiments that

• examine genetic basis for ozone tolerance in soybean,
• test effects of elevated CO2 on resource acquisition by soybean, and
• evaluate ozone x temperature effects in soybean.

Fig. 1

Previous studies conducted by our Unit and others (NCLAN) showed that ambient O₃ pollution can suppress soybean, cotton, wheat and peanut yields by 5 to 15% (Fig.2). However, elevated atmospheric CO₂ ameliorates O₃ effects (Fig. 3).

Fig. 2

Fig. 3

Studies to determine the sources of these interactions are underway. Experiments in progress are examining elevated CO₂and O₃ effects on stomatal conductance, O₃ uptake, photosynthesis, transpiration and oxidative injury in soybean (Fig. 4). We are also investigating the effects of elevated CO₂ and O₃ on crop residue chemistry and decomposition (Fig. 5).

Fig. 4	Fig. 5

Increased biomass production with elevated while CO₂ increased residue inputs (Fig. 6), while O3-treated soybean leaf residues decomposed more slowly than residues from plants grown in clean air (Fig. 7).

Fig. 6. Aboveground soybean residue biomass remaining after harvest. Growth treatments: clean-air, ambient CO2 control (CF-370); elevated CO2 (CF-714); O3 (OZ-370); CO2 + O3 (OZ-714).	Fig. 7. Decomposition of soybean leaf residues after incubation in soil for 20 wks. Growth treatments: clean-air, ambient CO2 control (CF-370); elevated CO2 (CF-714); O3 (OZ-370); CO2 + O3 (OZ-714).

O3-induced decreases in carbohydrates and increases in phenolic polymers were associated with slower decomposition rates. Both elevated CO2 and O3 are expected to influence soil carbon sequestration and nitrogen mineralization rates. A new project in our laboratory involves the use of snap bean and Arabidopsis mutants with differential sensitivity to O3 injury. Experiments conducted in O3 exposure chambers in the NC State Phytotron (Fig. 8) examine genotype sensitivity to O3 in conjunction with gas-exchange, antioxidant metabolism and ethylene measurements to identify possible mechanisms to improve plant tolerance to ambient O3 pollution.

Fig. 8