Interactive Effects of Carbon Dioxide and Nitrogen Nutrition on Cotton Growth, Development, Yield, and Fiber Quality

from ambient levels of 360 mol mol 1 increased vegetative biomass by 40% and boll biomass by 20% (Reddy The consequences of elevated carbon dioxide concentrations et al., 1997). Open-top chamber experiments (Kimball ([CO2]) and N nutrition on cotton (Gossypium hirsutum L.) growth, and Mauney, 1993) showed that elevated [CO2] of 650 development, yield, and fiber quality were determined. Cotton cultivar mol mol 1 increased the aboveground biomass by 63% NuCOTN 33B was grown in sunlit controlled environment chambers at three levels of [CO2] (180, 360, and 720 mol mol 1) and two levels and seed cotton yield by 60% compared with plants of N [continuous N throughout the plant growth period (N ) and grown at ambient [CO2]. Similarly, results from FACE N withheld from flowering to harvest (N )]. Leaf N concentration experiments showed that CO2 enrichment (550 mol decreased with increasing [CO2] under both N treatments. These low mol 1) produced 35% more biomass and 60% more lint leaf N concentrations did not decrease the effect of elevated [CO2] yield compared with plants grown at ambient atmoin producing higher lint yields at both N treatments, the response spheric [CO2] (Mauney et al., 1994; Pinter et al., 1996). being highest for plants grown at elevated [CO2] and N conditions. Generally, increasing atmospheric [CO2] is shown to Fiber quality was not significantly affected by [CO2], but the leaf N have a stimulatory effect on plant biomass production as concentrations, which varied with [CO2], had either a positive or a a consequence of the rise in net photosynthesis (Bazzaz, negative influence on most of the fiber quality parameters. Leaf N 1990; Poorter, 1993, 1998). Although a strong response during boll maturation period had significant positive correlations of cotton yield to future CO2 increases was observed, with mean fiber length (r 2 0.63), fine fiber fraction (r 2 0.67), and other environmental factors are shown to modify this immature fiber fraction (r 2 0.65) and negative correlations with mean fiber diameter (r 2 0.61), short fiber content (r 2 0.50), fiber response (Poorter and Perez-Soba, 2001). cross-sectional area (r 2 0.76), average circularity (r 2 0.74), and The response of agricultural crops to future climate micronafis (r 2 0.65). It is inferred that future elevated [CO2] will change also depends on management practices. One key not have any deleterious effects on fiber quality and yield if N is environmental factor is nutrient availability, which is an optimum. The developed algorithms, if incorporated into processimportant factor influencing the extent of CO2 response level crop model, will be useful to optimize cotton production and of the plants (Poorter, 1998). Under field conditions, fiber quality. nutrients, particularly N, are often scarce. This may lead to intensification of competition of resources under elevated [CO2] (Zanetti et al., 1997). Increased rates of G atmospheric [CO2] has risen by more than growth in elevated [CO2] will normally lead to increased 30% since the preindustrial times, from about 280 demand for all mineral nutrients. It is important to admol mol 1 to the current levels of 370 mol mol 1 dress whether the lint quality of cotton, the world’s fore(Houghton et al., 2001). If current anthropogenic CO2 most important fiber crop, will be affected by higher emissions rates continue in the future, the most recent atmospheric [CO2] in interaction with other growthfuture scenarios of greenhouse gases in the atmosphere limiting major nutrients such as N. indicate that atmospheric [CO2] could increase from curInteraction of atmospheric [CO2] and N nutrition on rent levels to between 540 and 970 mol mol 1 by the cotton growth and development was previously adend of the 21st century (Houghton et al., 2001). With dressed in several short-duration experiments (Wong, concern over maintaining cotton fiber production in the 1979; Rogers et al., 1993, 1996a, 1996b; Conroy and Hockfuture environments, experiments on elevated [CO2] ing, 1993), which showed changes in nutritional physiolhave been conducted in cotton (Kimball and Mauney, ogy of the crop with elevated [CO2]. However, there 1993; Mauney et al., 1994; Pinter et al., 1996; Reddy are still basic questions on how plants will respond to et al., 2000). Techniques used varied from controlledelevated atmospheric [CO2] when nutrients are limiting environment, open-top chambers to the application of (Bazzaz and Catovsky, 2002; Poorter and Navas, 2003; free-air CO2 enrichment (FACE) facilities. Results from Lloyd and Farquhar, 2000). The number of studies on sun-lit chambers showed that a 100% increase in [CO2] the influence of [CO2] on lint yield and fiber quality is limited. Atmospheric [CO2] and temperature effects on K.R. Reddy and S. Koti, Dep. of Plant and Soil Sci., 117 Dorman Hall, Box 9555, Mississippi State Univ., Mississippi State, MS 39762, Abbreviations: AFIS, advanced fiber information system; A(n), averUSA; G.H. Davidonis, USDA-ARS, Southern Regional Res. Cent., age cross-sectional area of the fiber; BMP, boll maturation period; P.O. Box 19687, New Orleans, LA 70179, USA; and V.R. Reddy, [CO2], carbon dioxide concentration; DAE, days after emergence; USDA-ARS, Alternate Crops and Syst. Lab., Bldg. 001, Rm. 342, FACE, free-air CO2 enrichment; FFF, fine fiber fraction; IFF, immaBARC-W, 10300 Baltimore Ave., Beltsville, MD 20705, USA. Reture fiber fraction; leaf N-BMP, leaf nitrogen during boll maturation ceived 10 Oct. 2003. *Corresponding author ([email protected]). period; N , continuous nitrogen throughout the plant growth period; N , nitrogen withheld from flowering to harvest; SFC, short fiber Published in Agron. J. 96:1148–1157 (2004).  American Society of Agronomy content; SPAR, soil–plant–atmosphere research; , average circularity of the fiber; AFIS, micronafis. 677 S. Segoe Rd., Madison, WI 53711 USA