Progress 01/01/13 to 09/30/13
Outputs
Target Audience:The research and outreach activities in this project are all interdependent and co-directed to specific target audiences. These include growers and producers of agricultural commodities in the San Joaquin and Imperial Valleys, Farm Advisors in the Imperial and San Joaquin Valleys, startup companies interested in specific oilseed crops for biofuels, regulatory agencies specifically California Air Resources Board and US Environmental Protection Agency, and governmental entities including the National Climate Change Program,the California Energy Commission and the U.S. Forest Service Western Wildlands Threat Assessment Center. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The activities of this project were undertaken with the significant involvement of numerous individuals and entities. The project resulted in training of Farm Advisors and both graduate and undergraduate students. It also contributed to the outreach efforts of colleagues at several institutions. These include: Kent Burkey, USDA Agricultural Research Service, North Carolina. Fitz Booker, USDA Agricultural Research Service, North Carolina. Art Chappelka, Auburn University, Alabama. Howard Neufeld, Appalachian State University, North Carolina. Miguel Rea, Autonomous University of Queretaro, Mexico. Russel Muntifering, Auburn University, Alabama. Hai-Bang Vu, University of California at Riverside, California. Greg Harvey, US Air Force, Ohio. Andrew Jackson, Texas Tech University, Texas. R. Heath, University of California at Riverside, California. M. McGrath, Cornell University, New York. Nancy Grulke, USDA Forest. At University of California Riverside, the desert project involving biofuel sorghum allowed training of 2 graduate students and 3 undergraduate students in research methods, along with 2 postdoctoral associates. How have the results been disseminated to communities of interest?these results have been presented at Research Center Field Days, at professional conferences, and at campus and Research Center seminars. In addition, the work has been published in peer reviewed journals. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
During this reporting period of our continuing project on Characterization and Mechanisms of Plant Responses to Ozone in the US, we have accomplished many of the originally identified goals. Following on preliminary results in previous reporting periods, we have assisted the US Air Force in determining the potential for ozone air pollution to cause plants to synthesize or accumulate perchlorate, and thereby increase its concentration in the environment. We have similarly demonstrated that the potential for mitigation of ozone damage to vegetation by application of jasmonic acid esters is likely to be limited. We also provided a clear demonstration to air quality modelers that there are distinct diurnal periodicities in sensitivity of vegetation to ozone. Our results were incorporated into the US EPA periodic (5 year) Integrated Science Assessment for Ozone Impacts. Ongoing research resulted in Grantz's participation in the federal committee that oversees this process (CASAC). We have concluded a study of ambient and near ambient ozone concentrations on perchlorate levels in a wide range of crop plants. We have determined that even veryhigh levels of ozone as observed during incursion of stratospheric air, or during extremely unhealthful episodes in urban areas in the developing world, are not responsible for formation in planta ofperchlorates.These results remove one of the most promising possible explanations for recently discovered widespread distribution of perchlorate in the environment, including in important surface and subterranean aquifers. We have demonstrated that C4 photosynthetic pathways are not protective of plants against ozone, and that ozone sensitivity exhibits a clear diurnal timecourse. In a multi-year field experiment in the low desert of California we have demonstrated that sorghum may be a valuable and highly productive feedstock for biofuel production. Biofuel production may remove some sources of atmospheric pollution. We have shown that fertilized production of irrigated sorghum in this region may be a large a episodic source of reactive nitrogen and of nitrous oxide, which is a greenhouse gas. Further studies are in progress to evaluate the mechanisms and drivers of this gas exchange.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
D.A. Grantz, G. D. Jenerette, P. Oikawa, C. Fertitta, J. Eberwein. 2013. DRIVERS OF SOIL RESPIRATION IN ARID BIOFUEL PRODUCTION SYSTEMS. Association for the Advancement of Industrial Crops. Washington DC
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Grantz, D.A., Vu, H.-B., Heath, R.L., Burkey, K.O. 2013. Demonstration of a diel trend in sensitivity of Gossypium to ozone: a step toward relating O3 injury to exposure or flux. Journal of Experimental Botany 64: 1703-1713.
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Stephen Kaffka, Robert Hutmacher, David Grantz, Santiago Bucaram, Jimin Zhang, Nicholas George, Dan Marcum, Steve Wright. 2013. CALIFORNIA TRANSPORTATION FUELS CROPS DEVELOPMENT AND DEMONSTRATION PROJECT. California Energy Commission. Sacramento CA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
L.Y. Liang, J.R. Eberwein1, P.Y. Oikawa, G.D. Jenerette, D.A. Grantz. 2013. CO2, N2O and NOx Flux of a Biofuel Agro-ecosystem in Southern California. American Geophysical Union Annual Meeting, San Francisco.
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Walthall, C. L., J. Hatfield, P. Backlund, L. Lengnick, E. Marshall, M. Walsh, S. Adkins,
M. Aillery, E. A. Ainsworth, C. Ammann, C. J. Anderson, I. Bartomeus, L. H. Baumgard, F. Booker, B. Bradley, D. M. Blumenthal, J. Bunce, K. Burkey, S. M. Dabney, J. A. Delgado, J. Dukes, A. Funk, K. Garrett, M. Glenn, D. A. Grantz, D. Goodrich, S. Hu, R. C. Izaurralde, R. A. C. Jones, S. H. Kim, A. D. B. Leaky, K. Lewers, T. L. Mader, A. McClung, J. Morgan, D. J. Muth, M. Nearing, D. M. Oosterhuis, D. Ort, C. Parmesan, W. T. Pettigrew, W. Polley, R. Rader, C. Rice, M. Rivington, E. Rosskopf, W. A. Salas, L. E. Sollenberger, R. Srygley, C. St�ckle, E. S. Takle, D. Timlin, J. W. White, R. Winfree, L. Wright-Morton, and L. H. Ziska. 2013. Climate change and agriculture in the United States: effects and adaptation. US Global Change Research Program National Climate Assessment Office. Washington, DC.
|
Progress 10/01/08 to 09/30/13
Outputs
Target Audience:include growers and producers of agricultural commodities in the San Joaquin and Imperial Valleys, Farm Advisors in the Imperial and San Joaquin Valleys, startup companies interested in specific oilseed crops for biofuels, regulatory agencies specifically California Air Resources Board and US Environmental Protection Agency, and governmental entities including the National Climate Change Program, the California Energy Commission and the U.S. Forest Service Western Wildlands Threat Assessment Center. Changes/Problems:The ozone impact physiological research proceeded as planned. The evaluation of air pollution and climate change impacts of sorghum production in the low desert encountered an early challenge. The project was initially to use Saccharum (sugarcane) but due to changes in the economic outlook, and departure of local private investors, a source of vegetative sugarcane planting material was lost. With NIFA concurrence we shifted the project to forage Sorghum, another equally promising feedstock. After that, the project went as planned. What opportunities for training and professional development has the project provided?The activities of this project were undertaken with the significant involvement of numerous individuals and entities. The project resulted in training of Farm Advisors and both graduate and undergraduate students. It also contributed to the outreach efforts of colleagues at several institutions. These include: Kent Burkey, USDA Agricultural Research Service, North Carolina. Fitz Booker, USDA Agricultural Research Service, North Carolina. Art Chappelka, Auburn University, Alabama. Howard Neufeld, Appalachian State University, North Carolina. Miguel Rea, Autonomous University of Queretaro, Mexico. Russel Muntifering, Auburn University, Alabama. Hai-Bang Vu, University of California at Riverside, California. Greg Harvey, US Air Force, Ohio. Andrew Jackson, Texas Tech University, Texas. R. Heath, University of California at Riverside, California. M. McGrath, Cornell University, New York. Nancy Grulke, USDA Forest. At University of California Riverside, the desert project involving biofuel sorghum allowed training of 2 graduate students and 3 undergraduate students in research methods, along with 2 postdoctoral associates. How have the results been disseminated to communities of interest?these results have been presented at Research Center Field Days, at professional conferences, and at campus and Research Center seminars. In addition, the work has been published in peer reviewed journals. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
During this reporting period of our continuing project on Characterization and Mechanisms of Plant Responses to Ozone in the US, we have accomplished many of the originally identified goals. Following on preliminary results in previous reporting periods, we have assisted the US Air Force in determining the potential for ozone air pollution to cause plants to synthesize or accumulate perchlorate, and thereby increase its concentration in the environment. We have similarly demonstrated that the potential for mitigation of ozone damage to vegetation by application of jasmonic acid esters is likely to be limited. We also provided a clear demonstration to air quality modelers that there are distinct diurnal periodicities in sensitivity of vegetation to ozone. Our results were incorporated into the US EPA periodic (5 year) Integrated Science Assessment for Ozone Impacts. Ongoing research resulted in Grantz's participation in the federal committee that oversees this process (CASAC). We have concluded a study of ambient and near ambient ozone concentrations on perchlorate levels in a wide range of crop plants. We have determined that even very high levels of ozone as observed during incursion of stratospheric air, or during extremely unhealthful episodes in urban areas in the developing world, are not responsible for formation in planta of perchlorates. These results remove one of the most promising possible explanations for recently discovered widespread distribution of perchlorate in the environment, including in important surface and subterranean aquifers. We have demonstrated that C4 photosynthetic pathways are not protective of plants against ozone, and that ozone sensitivity exhibits a clear diurnal timecourse. In a multi-year field experiment in the low desert of California we have demonstrated that sorghum may be a valuable and highly productive feedstock for biofuel production. Biofuel production may remove some sources of atmospheric pollution. We have shown that fertilized production of irrigated sorghum in this region may be a large a episodic source of reactive nitrogen and of nitrous oxide, which is a greenhouse gas. Further studies are in progress to evaluate the mechanisms and drivers of this gas exchange.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2008
Citation:
Grantz, D.A., A. Shrestha and H-B. Vu. 2008. Early vigor and ozone response in horseweed (Conyza Canadensis) biotypes differing in glyphosate resistance. Weed Science 56:224-230.
- Type:
Other
Status:
Published
Year Published:
2012
Citation:
Walthall, C.L., et al. 2012. Climate Change and Agriculture: Effects and Adaptation. US Global Change Research Program National Climate Assessment Office.
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Grantz, D.A. and Vu, H-B. 2012. Root and Shoot Gas Exchange Respond Additively to Moderate Ozone and Methyl Jasmonate without Induction of Ethylene: Ethylene is induced at higher O3. Journal of Experimental Botany 63: 4303 to 4313.
- Type:
Journal Articles
Status:
Published
Year Published:
2008
Citation:
Grantz, D.A., A. Shrestha and H-B. Vu. 2008. Ozone enhances the adaptive benefit of glyphosate resistance in California horseweed (Conyza canadensis). Weed Science 56: 549-554.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2008
Citation:
Krupa, S., F. Booker, V. Bowersox, D. Grantz and C. Lehmann. 2008. Uncertainties in the current knowledge of some atmospheric trace gases associated with US agriculture. Journal of the Air and Waste Management Assoc. 58: 986 -993.
- Type:
Journal Articles
Status:
Published
Year Published:
2008
Citation:
Booker, F., R. Muntifering, M. McGrath, K. Burkey, D. Decoteau, E. Fiscus, W. Manning, S. Krupa, A. Chappelka, and D. Grantz. 2008. The ozone component of global change: Effects on agricultural and horticultural plant yield, product quality, and interactions with invasive species. Journal of Integrative Plant Biology doi: 10.1111/j.1744-7909.2008.00805.x. Vol. 51: p.337-351.
- Type:
Journal Articles
Status:
Published
Year Published:
2009
Citation:
Grantz, D.A., Vu, H. 2009. Ozone sensitivity in a potential C4 Bio-Energy Crop: Sugarcane in California. Crop Science. Vol. 49: p.643 - 650.
- Type:
Journal Articles
Status:
Published
Year Published:
2010
Citation:
Grantz, D.A., Shrestha, A., Vu, H. 2010. Ozone Impacts on Assimilation and Allocation to Reproductive Sinks in the Vegetatively Propagated C4 Weed, Yellow Nutsedge. Crop Science 50: 246-252.
- Type:
Journal Articles
Status:
Published
Year Published:
2010
Citation:
Grantz, D.A., Vu, H., Aguilar, C., Rea, M.A. 2010. No Interaction Between Methyl Jasmonate and Ozone in Pima Cotton: Growth and allocation respond independently to both. Plant Cell and Environment. 33: 717-728.
- Type:
Book Chapters
Status:
Published
Year Published:
2010
Citation:
P. Temple and D.A. Grantz. 2010. Air Pollution Stress. In: M. Stewart, D. Oosterhuis and J. Heitholt (eds), Cotton Physiology II.
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Grantz, D.A., Vu, H-B., Tew, T.L. Veremis, J.C. 2012. Sensitivity of gas exchange parameters to ozone in diverse C4 sugarcane hybrids. Crop Science 52(3).
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2010
Citation:
Grantz, D.A., Vu, H-B., Heath, R.L., Burkey, K. 2010. Temporal sensitivity key to modeling ozone impacts on vegetation. Abstract 2010-EE-208-AWMA. Annual Meeting of the Air and Waste Management Assoc. Calgary. 22-25 June 2010.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2012
Citation:
Grulke, N. E., Paoletti, E., Grantz, D., Matyssek, R. 2012. Changes in threshold for Ps and gs decoupling with increasing O3 concentrations in cultivated and uncultivated species. International Air Pollution Workshop. Kaunas Lithuania.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2012
Citation:
Grantz, David A., Jackson, Andrew, Burkey, Kent, McGrath, Margaret, Harvey, Greg. 2012. Controlled exposures at near ambient concentrations do not suggest a role for tropospheric ozone in plant production of perchlorate.International Air Pollution Workshop. Kaunas Lithuania.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
D.A. Grantz, G. D. Jenerette, P. Oikawa, C. Fertitta, J. Eberwein. 2013. DRIVERS OF SOIL RESPIRATION IN ARID BIOFUEL PRODUCTION SYSTEMS. Association for the Advancement of Industrial Crops. Washington DC
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Grantz, D.A., Vu, H.-B., Heath, R.L., Burkey, K.O. 2013. Demonstration of a diel trend in sensitivity of Gossypium to ozone: a step toward relating O3 injury to exposure or flux. Journal of Experimental Botany 64: 1703-1713.
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Stephen Kaffka, Robert Hutmacher, David Grantz, Santiago Bucaram, Jimin Zhang, Nicholas George, Dan Marcum, Steve Wright. 2013. CALIFORNIA TRANSPORTATION FUELS CROPS DEVELOPMENT AND DEMONSTRATION PROJECT. California Energy Commission. Sacramento CA.
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Walthall, C. L., J. Hatfield, P. Backlund, L. Lengnick, E. Marshall, M. Walsh, S. Adkins,
M. Aillery, E. A. Ainsworth, C. Ammann, C. J. Anderson, I. Bartomeus, L. H. Baumgard, F. Booker, B. Bradley, D. M. Blumenthal, J. Bunce, K. Burkey, S. M. Dabney, J. A. Delgado, J. Dukes, A. Funk, K. Garrett, M. Glenn, D. A. Grantz, D. Goodrich, S. Hu, R. C. Izaurralde, R. A. C. Jones, S. H. Kim, A. D. B. Leaky, K. Lewers, T. L. Mader, A. McClung, J. Morgan, D. J. Muth, M. Nearing, D. M. Oosterhuis, D. Ort, C. Parmesan, W. T. Pettigrew, W. Polley, R. Rader, C. Rice, M. Rivington, E. Rosskopf, W. A. Salas, L. E. Sollenberger, R. Srygley, C. St�ckle, E. S. Takle, D. Timlin, J. W. White, R. Winfree, L. Wright-Morton, and L. H. Ziska. 2013. Climate change and agriculture in the United States: effects and adaptation. US Global Change Research Program National Climate Assessment Office. Washington, DC.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
L.Y. Liang, J.R. Eberwein1, P.Y. Oikawa, G.D. Jenerette, D.A. Grantz. 2013. CO2, N2O and NOx Flux of a Biofuel Agro-ecosystem in Southern California. American Geophysical Union Annual Meeting, San Francisco
|
Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: During this reporting period of our continuing project on Characterization and Mechanisms of Plant Responses to Ozone in the US, we have accomplished many of the originally identified goals. Following on preliminary results in previous reporting periods, we have assisted the US Air Force in determining the potential for ozone air pollution to cause plants to synthesize or accumulate perchlorate, and thereby increase its concentration in the environment. We have similarly demonstrated that the potential for mitigation of ozone damage to vegetation by application of jasmonic acid esters is likely to be limited. We also provided a clear demonstration to air quality modelers that there are distinct diurnal periodicities in sensitivity of vegetation to ozone. PARTICIPANTS: The activities of this project were undertaken with the significant involvement of numerous individuals and entities. The project resulted in training of Farm Advisors and both graduate and undergraduate students. It also contributed to the outreach efforts of colleagues at several institutions. These include: Kent Burkey, USDA Agricultural Research Service, North Carolina. Fitz Booker, USDA Agricultural Research Service, North Carolina. Art Chappelka, Auburn University, Alabama. Howard Neufeld, Appalachian State University, North Carolina. Miguel Rea, Autonomous University of Queretaro, Mexico. Russel Muntifering, Auburn University, Alabama. Hai-Bang Vu, University of California at Riverside, California. Greg Harvey, US Air Force, Ohio. Andrew Jackson, Texas Tech University, Texas. R. Heath, University of California at Riverside, California. M. McGrath, Cornell University, New York. Nancy Grulke, USDA Forest Service, Oregon. TARGET AUDIENCES: All activities in this project are directed to specific target audiences. These include growers and producers of agricultural commodities in the San Joaquin and Imperial Valleys, Farm Advisors in the Imperial and San Joaquin Valleys, startup companies interested in specific oilseed crops for biofuels, regulatory agencies specifically California Air Resources Board and US Environmental Protection Agency, and governmental entities including the National Climate Change Program and the California Energy Commission. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Our results were incorporated into the US EPA periodic (5 year) Integrated Science Assessment for Ozone Impacts. Ongoing research resulted in Grantz's participation in the federal committee that oversees this process (CASAC). We have concluded a study of ambient and near ambient ozone concentrations on perchlorate levels in a wide range of crop plants. We are yet to determine if higher levels of ozone as observed during incursion of stratospheric air may cause perchlorate accumulation. We have demonstrated that C4 photosynthetic pathways are not protective of plants against ozone, and that ozone sensitivity exhibits a clear diurnal timecourse.
Publications
- Walthall, C.L., et al. 2012. Climate Change and Agriculture: Effects and Adaptation. US Global Change Research Program National Climate Assessment Office.
- Grantz, D.A. and Vu, H-B. 2012. Root and Shoot Gas Exchange Respond Additively to Moderate Ozone and Methyl Jasmonate without Induction of Ethylene: Ethylene is induced at higher O3. Journal of Experimental Botany 63: 4303 to 4313.
- Grulke, N. E., Paoletti, E., Grantz, D., Matyssek, R. 2012. Changes in threshold for Ps and gs decoupling with increasing O3 concentrations in cultivated and uncultivated species. International Air Pollution Workshop. Kaunas Lithuania.
- Grantz, David A., Jackson, Andrew, Burkey, Kent, McGrath, Margaret, Harvey, Greg. 2012. Controlled exposures at near ambient concentrations do not suggest a role for tropospheric ozone in plant production of perchlorate.International Air Pollution Workshop. Kaunas Lithuania.
|
Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: In collaboration with other members of the NE-1030 Multi-State Committee we have conducted several series of experiments to determine if ground level ozone may be contributing to the distribution of perchlorate across the land surface and in ground water. We have determined that the potential ozone protective compound, methyl jasmonate, is unlikely to be effective against ozone at ambient levels because there is little interaction between ozone and jasmonate at these levels. We have further demonstrated that there is a distinct time of day effect on ozone sensitivity, and have created a candidate sensitivity parameter and method of quantifying it, that can overcome a deficiency in current models of landscape scale ozone impacts. We have evaluated the potential ozone sensitivity of candidate biofuel feedstocks across a range of sorghum and Saccharum genotypes. PARTICIPANTS: The outcomes for this project represent the effective collaboration of K. Burkey, H-B. Vu, G. Harvey, A. Jackson, and R. Heath. TARGET AUDIENCES: The project targets the U.S. Global Change Program, the U.S. Environmental Protection Agency, California Air Resources Board, various local air districts, growers and processors of food, fiber and bioenergy crops in California and in other ozone impacted areas of the U.S. PROJECT MODIFICATIONS: We began exposures of multiple crop species to ozone at near ambient levels. We later added an unplanned series of exposures at super-ambient levels to provide reduced uncertainty regarding conclusions.
Impacts
The results of these studies have been incorporated into the most recent Integrated Science Assessment for Ozone created by U.S. Environmental Protection Agency impacting potential regulatory considerations. Results have been incorporated into the U.S. Air Force threat evaluation for perchlorates in ground water and consumable leafy vegetables.
Publications
- Grantz, D.A., Vu, H-B., Tew, T.L. Veremis, J.C. 2012. Sensitivity of gas exchange parameters to ozone in diverse C4 sugarcane hybrids. Crop Science 52(3).
- Grantz, D.A., Vu, H-B., Heath, R.L., Burkey, K. 2010. Temporal sensitivity key to modeling ozone impacts on vegetation. Abstract 2010-EE-208-AWMA. Annual Meeting of the Air and Waste Management Assoc. Calgary. 22-25 June 2010.
|
Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: The project provided data on the ozone component of Global Change on ozone impacts on important C4 species, on weed-crop interactions, and on the basic biology of plant hormone mediated responses to ozone. The project evaluated the potential for biogenic generation of the rocket fuel residue, perchlorate, in the presence of ozone air pollution. The project developed the first model of diurnal changes in ozone sensitivity of vegetation to advise regional and global simulations of ozone impacts. The project assessed clonal differences among Saccharum cultivars in ozone sensitivity of growth and photosynthetic competence. These outputs were disseminated to various grower and producer groups through personal interactions, field days, publications, and in response to telephone or email queries. PARTICIPANTS: P. Temple, CA A. Shrestha, CA H-B. Vu, CA G. Harvey, OH A. Jackson, TX R. Heath, CA K. Burkey, NC M. McGrath, NY T. Best, PA W. Manning, MA F. Booker, NC A. Chappelka, AL E. Ainsworth, IL B. Zilinskas, NJ TARGET AUDIENCES: Growers, processors, regulatory groups, environmental groups. PROJECT MODIFICATIONS: We have continued the non-operation of field exposure chambers, and continue to assess the ozone responses of clonal Saccharum materials that may be suitable for biofuel feedstock production in California.
Impacts
As a result of these research efforts Grantz was able to serve on the Clean Air Scientific Advisory Committee (CASAC) Ozone NAAQS Committee which will assess the state of ozone impacts research preparatory to development of the National Ambient Air Quality Standard. Data on the ozone component of global change was incorporated by US EPA into the recently released draft of the "Integrated Science Assessment for Ozone and Related Photochemical Oxidants", this included conclusions that C4 photosynthesis does not protect global vegetation from ozone damage, and that ozone has strong impacts on weed-crop interactions. At a more basic level the Integrated Science Assessment utilized data suggesting that in some crop species the plant hormone Methyl Jasmonate, does not protect plants against ozone. Data on biogenic generation of perchlorate in the presence of ozone air pollution was provided to the US Air Force environmental program in their efforts to understand the global distribution of the rocket fuel residue, perchlorate. Data to date have not supported the hypothesis that environmental levels of ozone lead to biogenic perchlorate production in crop plants. Data on diurnal trends in ozone defenses in vegetation has led to a preliminary model of changes in antioxidant activity on short time scales. These data will inform larger scale models that are used to predict ozone impacts on crops and native vegetation. Data on clonal differences among Saccharum cultivars in ozone sensitivity of growth and photosynthetic competence was provided to potential growers and biofuel processors in arid regions of California and throughout the western US.
Publications
- P. Temple and D.A. Grantz. 2010. Air Pollution Stress. In: M. Stewart, D. Oosterhuis and J. Heitholt (eds), Cotton Physiology II.
|
Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Technical information was provided to environmental and regulatory workgroups to inform activities related to ground level ozone. Handouts and email correspondence on similar issues were provided for several clients. Research results are being incorporated into the US EPA Integrated Science Assessment for Ozone which is now underway. PARTICIPANTS: Sagar Krupa; Univ. Minnesota Fitzgerald Booker; USDA and North Carolina State Univ. Margaret McGrath; Cornell University Steven Long; Univ. of Illinois Art Chapelka; Auburn University John King; North Carolina State Univ. William Manning; Univ. of Massechussettes Russel Muntifering; Auburn Univ. Howard Neufeld; Appalachian State Univ. Barbara Zilinskas; Rutgers Univ. Kent Burkey; USDA and North Carolina State Univ. Robert Heath, University of California Riverside Darrel Jenerette, University of California Riverside The individuals above and their organizations have participated in the work of this multi-state project in many ways. The annual meeting and research workshop held by this group is a primary means of research communication among the US researchers in ozone effects. Individual projects at each institution as well as joint review and experimental projects grow out of these meetings. Our participation in the project has involved direct experimental collaboration with Kent Burkey and Robert Heath, and collaboration in preparation of a review article with many members listed above. TARGET AUDIENCES: This multi-state group has provided technical information to the USDA Agricultural Air Quality Task Force, has written review articles summarizing current threats posed by ozone air pollution, and conducted research to further characterize these threats. The target audiences are agricultural producers and agricultural policy makers, environmental regulatory agencies, and the scientific community. PROJECT MODIFICATIONS: We have currently discontinued use of the field exposure chambers due to cost. The greenhouse exposure chambers are suitable for younger plants, and in this case provide a more controlled exposure which is preferred for mechanistic studies. We have incorporated a screening of potential biofuel species for ozone tolerance, into the plan. This may be an important determinant of suitability in California since these clonal materials originate in areas without ozone air pollution. Both the San Joaquin and Imperial Valleys are subject to ozone.
Impacts
Further details on the costs and benefits of ozone regulatory activity were made available to regulatory groups. Activities of advocacy groups were aligned with current research results. New information on the role of ozone in the development of herbicide resistance in weeds was developed and extended. Grantz was invited to join the federal panel that reviews the developing ozone science assessment, where considerable influence on outcomes is expected.
Publications
- Booker, F., Muntifering, R., McGrath, M., Burkey, K., Decoteau, D., Fiscus, E., Manning, W., Krupa, S., Chappelka, A., Grantz, D. 2009. The ozone component of global change: Potential effects on agricultural and horticultural plant yield, product quality, and interactions with invasive species. Journal of Integrative Plant Biology. Vol. 51: p.337-351.
- Grantz, D.A., Vu, H. 2009. Ozone sensitivity in a potential C4 Bio-Energy Crop: Sugarcane in California. Crop Science. Vol. 49: p.643 - 650.
- Grantz, D.A., Shrestha, A., Vu, H. 2010. Ozone Impacts on Assimilation and Allocation to Reproductive Sinks in the Vegetatively Propagated C4 Weed, Yellow Nutsedge. Crop Science 50: 246-252.
- Grantz, D.A., Vu, H., Aguilar, C., Rea, M.A. 2010. No Interaction Between Methyl Jasmonate and Ozone in Pima Cotton: Growth and allocation respond independently to both. Plant Cell and Environment. (in press)
|
Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: The project continued the appraisal of ozone impacts on crop competition by yellow nutsedge. We expanded the generalization drawn from meta-analysis that ozone decreases allocation below-ground, by showing that increased competitiveness of nutsedge under high ozone exposures is not due to enhanced allocation of biomass to reproductive tubers, but rather to relative shoot sensitivity to ozone. We also demonstrated that allocation to roots is decreased in sugarcane by ozone, even though a large carbohydrate reservoir is present between shoot and root. We demonstrated that ozone is driving the local horseweed population toward glyphosate resistance by synergy with glyphosate in removing glyphosate-sensitive individuals from the population. A rapid gas exchange system was developed and has been used to demonstrate that chronic ozone may reduce stomatal control of water loss in trees. We demonstrated a general protective effect of CO2 enrichment against ozone damage in soybean and in northern forest tree species. Data continue to be accumulated that indicate the best averaging period for the USEPA-determined secondary standard for ozone, that will be protective of vegetation. PARTICIPANTS: Dr. Anil Shrestha, UCCE weed ecologist and farm advisor with the UC IPM project; Dr. Miguel Rea, Autonomous University of Queretaro, Mexico; Ms. Hai-Bang Vu, staff researcher in the PI's laboratory; Dr. Thomas Tew, USDA/ARS Sugarcane Breeding Laboratory Houma Louisiana; Lisa Ainsworth, University of Illinois and USDA/ARS; Fitzgerald Booker, USDA/ARS Raleigh NC; Kent Burkey, USDA/ARS Raleigh NC; Dennis Decoteau, Pennsylvania State University; Nancy Grulke, US Forest Service Riverside CA; David Karnosky, Michigan Technological University; Rainer Matyssek, Technical University of Munich, Germany; Margaret McGrath, Cornell University; Russel Muntifering, Auburn University; Howard Neufeld, Appalachian State University; Kevin Percy, Canadian Forest Service; Heinrich Sandermann, University of Frieburg Germany; Cosima Wiese, College of Misericordia; Barbara Zilinskas Rutgers University. TARGET AUDIENCES: Three main target audiences: growers of annual and perennial crops in ozone-impacted regions of the US, populations living and breathing in these areas, regulatory agencies charged with crafting balanced air quality standards and air quality regulations. This project produces information ranging from basic science that underpins regulations and advances knowledge to very applied information that can be used in crop management decisions. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The data developed by this project has been used to inform California Air Resources Board and US EPA in devising ozone air quality standards. Information and guidance has been provided to the USDA Agricultural Air Quality Task Force. In the San Joaquin Valley, information has been provided to numerous UCCE Farm Advisors and through them to numerous grower groups and trade publications. The integrated information on diverse crops and forest species has allowed participants to provide generalized information on a variety of ozone air pollution-related topics to a wide range of clientele, in and outside of California.
Publications
- Grantz, D.A., A. Shrestha and H-B. Vu. 2008. Early vigor and ozone response in horseweed (Conyza Canadensis) biotypes differing in glyphosate resistance. Weed Science 56:224-230.
- Grantz, D.A., A. Shrestha and H-B. Vu. 2008. Ozone enhances the adaptive benefit of glyphosate resistance in California horseweed (Conyza canadensis). Weed Science 56: 549-554.
- Krupa, S., F. Booker, V. Bowersox, D. Grantz and C. Lehmann. 2008. Uncertainties in the current knowledge of some atmospheric trace gases associated with US agriculture. Journal of the Air and Waste Management Assoc. 58: 986 -993.
- Booker, F., R. Muntifering, M. McGrath, K. Burkey, D. Decoteau, E. Fiscus, W. Manning, S. Krupa, A. Chappelka, and D. Grantz. 2008. The ozone component of global change: Effects on agricultural and horticultural plant yield, product quality, and interactions with invasive species. Journal of Integrative Plant Biology doi: 10.1111/j.1744-7909.2008.00805.x.
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: The project successfully prepared an application for renewal of the project, to be called NE-1030, for a 5-year period through September 30, 2012. Continuing observations were made in a long-term experiment in a sub-alpine pasture in Switzerland to examine the impact of high N input on nutritive quality impacts of ozone. Experiments were conducted in the field to determine ozone injury to leaves and defoliation in an ozone-sensitive snap bean cultivar in New York. A new-gas exchange system was developed to directly measure ozone flux into a leaf in California. Other observations were made of effects on root genotoxicity of ozone in Pima cotton. Methyl jasmonate caused a suite of developmental changes reminiscent of ozone exposure. Glyphosate-resistant horseweed was less susceptible to being driven out of the population by the combination of high ozone and glyphosate than the wildtype glyphosate sensitive biotype. Experiments were conducted to show that elevated carbon
dioxide ameliorated ozone effects on soybean yield. Ozone treatment effects on biomass production dominated potential impacts on soil C dynamics. Observations were made to investigate the role of glutathione peroxidase in ozone signal transduction pathways. Observations were made to determine whether northern forests have the capacity for sustained growth stimulation due to elevated carbon dioxide and whether concurrent exposure to ozone compromises this growth stimulation. Leaves of aspen that expanded under elevated ozone had significantly lower leaf miner egg densities. Observations were made to improve use of exposure-based metrics for prediction of ozone damage to aspensuggesting use of growing season as the averaging period for a new Secondary Ozone Standard.
PARTICIPANTS: Collaborators with PI Grantz included Dr. Anil Shrestha, a weed ecologist and Farm Advisor with the University of California Integrated Pest Management Program, Dr. Miguel Rea of the Autonomous University of Queretaro, Ms. Hai-Bang Vu a staff research assistant in the PI's laboratory, Dr. Blaine Hanson of the USDA Agricultural Research Service, and Dr. Thomas Tew of the USDA Agricultural Research Service. Representatives of the Experiment Stations and other organizations who collaborated on this multistate project included: Ainsworth, Lisa (USDA-ARS), Booker, Fitzgerald (USDA-ARS), Burkey, Kent (USDA-ARS), Carlson, John (Pennsylvania State University), Decoteau, Dennis (Pennsylvania State University), Grulke, Nancy (US Forest Service), Karnosky, David (Michigan Technological University), King, John (NC State University), Knighton, Raymond (USDA-CSREES), Kubiske, Mark (US Forest Service), Matyssek, Rainer (Technical University of Munich, Germany), McGrath, Margaret
(Cornell University), Muntifering, Russ (Auburn University), Nelson, Neil (US Forest Service), Neufeld, Howard (Appalachian State University), Percy, Kevin (Canadian Forest Service), Sandermann, Heinrich University of Frieburg, Germany), Wiese, Cosima (College of Misericordia), and Zilinskas, Barbara (Rutgers University).
TARGET AUDIENCES: There are two distinct target audiences for the results of this multistate project during this reporting period. The first is growers of annual and perennial crops in the United States and the second is the population of the areas of the United States subject to elevated ozone concentrations in ambient air. The results of the project produce basic knowledge regarding the welfare effects of air pollution on vegetation and ecosystems. This information has regulatory relevance during the air quality standard setting processes at local, state and federal levels. The basic information is targeted to modelers, regulators, and scientists who seek to predict the impacts of global change including air pollution on vegetation, ecosystems, and human environments.
PROJECT MODIFICATIONS: Project NE 1013 ended and Project NE 1030 was approved during this reporting period.
Impacts
New knowledge: Ambient O3 caused severe injury to leaves and defoliation in the O3-sensitive snap bean cultivar, S156. Total weight of bean pods harvested for fresh-market consumption was 40 to 50% lower for S156 compared with the tolerant genotype (R331) when measurements taken in NY, NC, PA, NJ, and MD were analyzed together. A bio-energy crop, sugarcane, was found in California to be moderately sensitive to O3, suggesting a challenge, along with chilling and salinity, in introducing these highly productive tropical crops into arid western valleys. Assumed inherent O3 resistance among C4 species may need reexamination. A pasture exposed to O3 and N deposition in Switzerland showed that nutritive quality evaluated in Alabama was 7% lower for elevated O3 treatments due to altered cell-walls. Forbs increased from 23 to 36%, grasses decreased from 68 to 60%, and legumes decreased from 9 to 3% of biomass. Glyphosate-resistant horseweed has replaced the susceptible biotype
in the San Joaquin Valley of California , and was less likely to be driven out of the population by the combination of high O3 and glyphosate. Ozone pollution may thus contribute to rapid evolution of herbicide resistance and to rising crop production costs. A soybean-wheat no-till system in open-top chambers in North Carolina showed that elevated CO2 (550 ppm) increased soybean and wheat yield by 10 to 25% while O3 at 1.4 x ambient, 68 ppb) suppressed soybean yield by 11 to 27%. In combination, elevated CO2 ameliorated O3 effects on soybean yield. Forests have the capacity for sustained growth stimulation due to elevated CO2, but exposure O3 compromises this. Elevated CO2 and O3 have small effects on litter chemistry and specific rates of decomposition, but larger effects on soil organic matter. Methyl jasmonate simulated several effects of O3 exposure, including reduced root/shoot biomass allocation, reduced plant biomass production, and leaf lesions. However, applications of methyl
jasmonate did not alter plant response to O3. Exposure of Pima cotton shoots to O3 led to genetic damage in root tips. An alkaline single cell electrophoretic assay of isolated root tip cells visualized damaged DNA which increased with increasing O3 exposure. O3 impacts are systemic, and translocated products may be involved in reducing root proliferation. Screening of 30 soybean ancestors for O3-induced foliar injury in the greenhouse in North Carolina was a good predictor of injury in the field using open-top chambers, but not a good predictor of seed yield loss. Screening of germplasm for O3-tolerance based on foliar injury alone may not take into account the full range of O3 effects on seed yield. Soybean cultivars released over a 50-year period in Illinois exhibited no relationship between O3 tolerance and year of release. Outreach and undergraduate teaching: Educational materials were prepared for use by public-school teachers and UP students at the Air Quality Learning and
Demonstration Center at the University of Pennsylvania. A picture archive of foliar ozone injury was developed using common milkweed, along with air pollution and meteorological data.
Publications
- Grantz, D.A., Shrestha, A., and Vu, H-B. 2007. Additive Effects of Ozone and Glyphosate in California Horseweed may Contribute to Rise of Glyphosate Resistance. American Society of Agronomy Annual Meeting, Abstract No. 244-8.
- Grantz, D.A., Shrestha, A., and Vu, H-B. 2007. Ozone x Glyphosate Interaction in Glyphosate-Tolerant and -Resistant Horseweed in California. Weed Science Society of America Annual Meeting, Abstract No. 305.
- Grantz, D.A., Rea, M., Rodriguez-Munoz, M.E., Aguilar-Perez, C., and Vu, H-B. 2007. Comet Assay Indicates Genotoxicity in Roots Following Foliar Exposure to Ozone in Pima Cotton(Gossypium barbadense). International Air Pollution Workshop. Abstract.
- Oncley, S.P., Foken, T., Vogt, R., Kohsiek, W., DeBruin,H.A.R., Bernhofer, C., Christen, A., van Gorsel, E., Grantz, D., Feigenwinter, C., Lehner, I., Liebethal, D., Liu, H., Mauder, M., Pitacco, A., Ribeiro, L., and Weidinger, T. 2007. The Energy Balance Experiment EBEX-2000. Part I: Overview and energy balance. Boundary Layer Meteorology 123: 1-28.
- Temple, P. and D. A. Grantz. 2007. Air Pollution Stress. In M. Stewart, D. Oosterhuis, and J. Heitholt (eds.), Cotton Physiology II. (In press). Krupa, S., F. Booker, V. Bowersox, D. Grantz and C. Lehmann. 2007. Uncertainties in the current knowledge of some atmospheric trace gases associated with US agriculture. Journal of the Air and Waste Management Assoc. (In press).
- Grantz, D.A., A. Shrestha, and H-B. Vu. 2007. Early Vigor and Ozone Response in Horseweed (Conyza canadensis) Biotypes Differing in Glyphosate Resistance. Crop Science (In press).
- Grantz, D.A., A. Shrestha and H-B. Vu. 2007. Ozone enhances adaptive benefit of glyphosate resistance in horseweed (Conyza canadensis). Weed Science. (In press).
- Farber, R.J. et. al. (Grantz is 15th out of 19 randomly ordered authors). 2007. Obliterating the Dust in the Antelope Valley. Proceedings, Air and Waste Management Association Annual Meeting. Paper Number 384.
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Progress 01/01/06 to 12/31/06
Outputs
This project continues to explore the extent and mechanisms of ozone damage to key agricultural crop systems in this area. We have demonstrated that competition between cotton (a major regional crop) and yellow nutsedge (a longstanding weed problem in the area) is altered by ozone exposure of the mixed community. We have shown that horseweed (a newly emerging weed problem), which has just become resistant to the major herbicide, glyphosate, in this region, may also be developing resistance to ozone. The results of this project have demonstrated that the combination of ozone and glyphosate application provides a much stronger advantage to the glyphosate resistant biotype, relative to the susceptible biotype, than does either ozone or glyphosate, alone. Studies in progress will determine if this is a pleiotropic interaction or just the result of additive responses to the two stressors which lead to death and elimination of the susceptible biotype from mixed populations.
In each of these systems, and in a meta-analysis of the literature, this project has shown that ozone reduces allocation of biomass below ground. This is apparently a general and critical component of ozone impacts on plants and communities of vegetation.
Impacts
As a result of increasing population density, traffic, and industrialization, the San Joaquin Valley of California is changing from a rural agricultural area to a mixed urban-agriculture interface. One of the major issues facing the region is deteriorating air quality. Our demonstrations of the mechanisms of ozone damage to vegetation provide regulators at the local Air District and at the California Air Resources Board with up to date information on so called "welfare effects" of continuing ozone air pollution. These studies have identified a potential interaction between effective weed control practices in regional cropping systems and the increasing levels of tropospheric ozone. This information may serve as the basis for improved vegetation management in agricultural systems in this area. This project has demonstrated a general reduction in carbon sequestration below ground follow plant exposure to ozone. This may constrain efforts to sequester carbon in
agricultural systems to mitigate climate change.
Publications
- Grantz, D.A. and Shrestha, A. 2006. Tropospheric Ozone and interspecific competition between yellow nutsedge (Cyperus esculentus L.) and Pima cotton (Gossypium barbadense L.). Crop Science 46: 1879-1889.
- Grantz, D.A., Gunn, S. and Vu, H-B. 2006 Ozone impacts on plant development: A meta-analysis of root/shoot allocation and growth. Plant Cell and Environment 29: 1193-1209.
- Krupa, S., Booker, F., Bowersox, V. and D. Grantz. 2007. Uncertainties in the current knowledge of some atmospheric trace gases associated with U.S. agriculture. Journal of the Air and Waste Management Association (in press).
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Progress 01/01/05 to 12/31/05
Outputs
Ozone is the most damaging air pollutant to crop plants. This project improves crop loss assessment due to ozone and characterizes the mechanism of ozone damage. Both activities will help develop methods to protect food and fiber production from ozone and enhance food security. The Grantz laboratory has contributed substantially to the productivity of this project. We have found that ozone translocation of photosynthate more than photosynthesis itself, in Pima cotton. Under some conditions the ratios of key sugars in the root tissue changes in response to ozone, while staying constant in the leaf. These changes indicate that phloem loading, the mechanism by which plants move sugar from leaves to roots, is inhibited by ozone. Under other conditions, particularly in field exposure chambers, the variability was such that these changes could not be demonstrated. Under these field conditions we used imaging software to characterize the altered shape and size of root
systems of plants exposed to ozone. The tap root system of cotton is reduced in length and diameter, and the main response to ozone is reduced linear growth of the root axis. This reduces root branching and has the largest effect on total root extension, length and density. The specific respiration of root tips of cotton increased with ozone exposure of the leaves. The results of our studies at the whole plant level integrate with the studies of other participants in the project at biochemical and molecular levels to provide preliminary mechanisms for the previously identified reduction of plant water transport capacity (hydraulic conductance). We showed by meta-analysis that ozone effects on allocation of biomass to roots are independent of effects on total plant growth and that the inhibition of root growth gives a competitive advantage to specific weed species that threaten cotton productivity, particularly under future climatic conditions. The project is developing means to better
predict yield and productivity losses under specific real world conditions, and is working to improve management and breeding strategies and to improve plant resistance to ozone. These efforts must focus, at least in part, on maintenance of root growth, and not exclusively on maintenance of shoot or total plant growth.
Impacts
Ozone air pollution is increasing in key agricultural areas such as the San Joaquin Valley of California and is inhibiting production of food and fiber. Using chambered and chamberless exposure designs this project is determining the nature, magnitude and mechanisms of ozone damage to key crop and wildland plant species. This information will allow regulators and land use planners to manage resources more effectively, and with improved awareness of the likely impacts of the ozone component of global change. The results of this project suggest that phloem loading may be a primary target of ozone toxicity, that root growth may respond to ozone separately from plant growth, and that reduced root development due to ozone give a competitive advantage to several weed species. These data will improve our ability to predict yields of crop and forested systems, contribute to methods of crop improvement for these polluted environments, and predict the effectiveness of suggested
schemes of carbon sequestration below ground as a way to reduce the increase in carbon dioxide and global temperature.
Publications
- Shrestha, A. and D.A. Grantz. 2005. O3 impacts on competition between tomato and yellow nutsedge: Above- and below-ground. Crop Sci. 45:1587-1595.
- Grantz, D.A. and A. Shrestha. 2006. Tropospheric O3 and interspecific competition between Yellow Nutsedge (Cyperus esculentus L.) and Pima Cotton (Gossypium barbadense L.). Crop Science (in press).
- Grantz, D. A., S. Gunn and H-B. Vu. 2006. O3 impacts on plant development: A meta-analysis of root/shoot allocation and growth. Plant Cell and Environment. (in press).
- Grantz, D., A. Shrestha and T. Prather. 2006. Vegetation management and competition in future ozone climates. Proceedings of the Workshop on Agricultural Air Quality: State of the Science, 5-8 June 2006, Potomac, MD, USA. (in press).
- Krupa, S., F. Booker, V. Bowersox and D. Grantz. 2006. Uncertainties in the current knowledge of atmospheric trace gases associated with cropping systems in the U.S. Proceedings of the Workshop on Agricultural Air Quality: State of the Science, 5-8 June 2006, Potomac, MD, USA. (in press).
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Progress 01/01/04 to 12/31/04
Outputs
The California membership of this multi-state project (Grantz) hosted a meeting of all participants at the University of California, Kearney Agricultural Center in Parlier California. Collaboration on the mechanism of ozone action was discussed and considerable progress was reported. In California the role of phloem loading and sugar profiles in sink and source tissues has been described. In temperature controlled greenhouse chambers a clear pattern emerged of a reduced ratio of sucrose to raffinose and stachyose (raffinose series sugars) in both cotton and muskmelon (cantaloupe). However, under field chamber exposure conditions, the variability in sugar concentrations in sink tissue precluded identification of this pattern. Further research is required to determine the reason for the discrepancy. At present an interaction with root temperature is the likely explanation. Under field conditions the soil heats up more than under greenhouse conditions, despite insulating
and reflecting pot covers, and respiration may proceed at a more rapid rate. Our results have indicated a positive response of root respiration to ozone exposure of the shoot. This is opposite to the hypothesized effect, which would have been driven by reduced substrate available for transport from the source leaves. The well-documented impacts of ozone on bioproductivity and on the root to shoot biomass ratio (reduced) were observed in both cotton and melon, and under both greenhouse and field conditions. The consequences of reduced allocation of biomass to root systems has previously been described for hydraulic conductance, and indirectly for shoot gas exchange (photosynthetic) performance. Both are reduced by ozone exposure of the shoot, apparently by direct and indirect mechanisms. We have documented the interaction of ozone on vegetative productivity of tomato and Pima cotton, repeating experiments reported last year. Tomato is relatively ozone resistant, and its competitiveness
will respect to the C4 weed, yellow nutsedge, actually increases with increasing ozone concentration, particularly at levels above current ambient concentrations. At lower concentrations the competitiveness of tomato is reduced marginally. In contrast, Pima cotton is sufficiently sensitive to ozone that its competitiveness with respect to yellow nutsedge is reduced further with each increment of ozone exposure, beginning at extremely low ozone concentrations. This demonstrates that higher order interactions of ozone with other stressors, including biotic and abiotic stressors, is difficult to predict in the absence of specific information about the entire system, and more detailed mechanistic information. The outcomes of such interactions may determine such factors as crop loss to weeds, and the costs of vegetation management.
Impacts
Using chambered and chamberless exposure designs this group is determining the nature, magnitude and mechanisms of ozone damage to key crop and wildland plant species. This information will allow regulators and land use planners to manage resources more effectively, and with improved awareness of the likely impacts of the ozone air pollution component of ongoing global change. These may be significant as ozone reduces crop yields, alters weed-crop competition, and reduces carbon sequestration below ground.
Publications
- Grantz, D.A. 2004. Ozone Impacts on Plants. In: P. Dwivedi and R.S. Dwivedi (eds.) Physiology of Abiotic Stress in Plants. Oxford IBH Publishing Co, New Delhi.
- Grantz, D.A. and Shrestha, A. 2004. Ozone Effects on Cotton versus Nutsedge Competition: An Ozone Sensitive Crop. Abstracts, American Society of Agronomy Annual Meeting, Seattle WA, October 2004.
- Shrestha, A. and Grantz, D.A. 2004. Ozone Effects on Tomato versus Nutsedge Competition: An Ozone Tolerant Crop. Abstracts, American Society of Agronomy Annual Meeting, Seattle WA, October 2004.
- Grantz, D.A. and Shrestha, A. 2004. Rising tropospheric ozone increases the competitive ability of yellow nutsedge versus Pima cotton. Abstract 414, WSSA Abstracts, 2005 Meeting of the Wed Science Society of America, Honolulu HI, February 2005.
- Grantz, D.A. and Shrestha, A. 2004. Ozone enhances allocation to tubers in yellow nutsedge but has little effect on competition with an ozone tolerant crop, tomato. Abstract 197, WSSA Abstracts, 2005 Meeting of the Wed Science Society of America, Honolulu HI, February 2005.
- Grantz, D.A. and Sanz, M.J. 2004. Common CoOccurrence of Citriculture and Ozone Air Pollution: Potential for Yield Reductions. Proceedings 10th International Society of Citriculture Congress. Paper No. 97.
- Murray, A.K. and Grantz, D.A. 2004. Carbohydrate composition of cotton aphid honeydew. Proceedings of the 2004 Beltwide Cotton Conferences, San Antonio TX January 2004. Pages 1590 to 1593.
- Grantz, D.A. and Murray, A.K. 2004. Effect of ozone on phloem transport in cotton. Proceedings of the 2004 Beltwide Cotton Conferences, San Antonio TX January 2004. Pages 2144 to 2149.
- Grantz, D.A. and Shrestha, A. 2004. Ozone affects competition between cotton and nutsedge. Proceedings of the 2004 Beltwide Cotton Conferences, San Antonio TX January 2004. Pages 2877 to 2882.
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