action of CO3, Oj. and ribulose-l ,5-diphosphale carboxy- 

 lase. Plant Physiol. 



Laing. W. A.. W. L. Ogren and R. H. Hageman. 1^75. Bicar- 

 bonate stabilization of ribulose-l,. ''-diphosphate carboxylase. 

 Biochemistry 14:2269-227.S. 



Moreland, D. E., and J. L Hilton. 1976. Actions on photosyn- 

 thetic systems. In: Herbicides: Physiology. Biochemistry. 

 Ecology. Vol. 1. Academic Press. London, pp. 493-52.1. 



Peters. D. V., B. F. Clough. R. A. Carves, and G. R. Stahl 

 1974. Measurement of dark respiration evaporation, and pho- 

 tosynthesis in field plots. Agron. J. .3:460-462. 



Potter. J. R. and J. S. Boyer. 197.3. Chloroplast response to 

 low leaf water potentials. Role of osmotic potentials. Plant 

 Physiol. 51:993-997. 



Nitrogen Fixation 



Basic research has contributed new knowledge 

 on the genetics of rhizobium (the best known of 

 the nitrogen-fixing microorganisms), on toxic 

 substances produced by this bacterium, and on 

 environmental factors controlling nitrogen-fixing 

 processes. Other advances have been made in our 

 knowledge of the nitrogen cycle and plant absorp- 

 tion and utilization of nitrogen in its various 

 forms. Since nitrogen makes up a major part of 

 the fertilizers used in crop production, under- 

 standing these processes is critical to development 

 of sound fertilizer conservation practices. Petro- 

 leum based fertilizers currently account for 35 

 percent of the total energy used in crop produc- 

 tion. 



Hutchison. G. L. R. J. Millington. and D. B. Peters. 1972. 

 Atmospheric ammonia: Absorption by plant leaves. Science 



175:771-772. 



Kissel. D. E., J. T. Ritchie, and C. W. Richardson. 1975. A 

 stress day concept to improve nitrogen fertilizer utilization: 

 Dryland grain sorghum in the Texas blackland prairie. Texas 

 Agr. Expt. .Sta. Mis. Pub. 1201. 15pp. 



Kuykendall. D. 1977. Introduction of potential sex factors into 

 Rhizobium japonicum. Proc. Conf. on genetic engineering for 

 nitrogen fixation. Brookhaven. (in press). 



Owens, L., J. Thompson. R. G. Pitcher, and T. Williams. 1972. 

 Structure of rhizobitoxine. an antimetabolic enol-ether amino 

 acid from Rhizobium japonicum. Chem. Communications, p. 

 714. 



Owens, I.. Rhizobitoxine as a postemergent herbicide. U.S. 

 Patent 3.672. 862. June 27. 1972. 



Porter. 1.. K.. F. G. Viets. Jr.. and G. L. Hutchison. 1972. Air 

 containing nitrogen- 15 ammonia: Foliar absorption by corn 

 seedlings. Science 175:759-761. 



Purvis, A. C, D. B. Peters, and R. H. Hageman. 1974. Effect 

 of carbon dioxide on nitrate accumulation and nitrate reduc- 

 tase induction in corn seedlings. Plant Physiol. 53:934-941. 



Sloger. C. and B. E. Caldwell. 1970. Seasonal pattern of ni- 

 trogen fixation in soybean. Abstr.. Northeast Amer. Soc. 

 Agron. Meetings, p. 7, 



Vigue, J.T.. J. E. Harper, and D. B. Peters. 1977. Nodulation 

 of soybeans grown hydroponically ou urea. Crop Sci. (in 

 press). 



Weber. D. F.. and V. L. Miller. 1972. Effect of soil tempera- 

 tures on the distribution of Rhizobium japonicum serogroups 

 in soybean nodules. Agron. J. 64:796-798. 



Environmental Stress, Remote Sensing, and 

 Crop Prediction 



Increased knowledge of the physiological and 

 biochemical effects of a large number of environ- 

 mental stress factors and development of effective 

 remote sensing technology contribute to develop- 

 ment of better protection methodology and model- 

 ing for predictive purposes. 



Bartholic. J. F.. L. N. Namken, and C, L. Wiegand. 1972. 

 Aerial thermal scanner to determine temperatures of soils and 

 of crop canopies differing in water stress. Agron. J. 64:603- 

 608. 



Flemming. A. L.. and C. D. Foy. 1968. Root structure reflects 

 differential aluminum tolerance in wheal varieties. Agron. J 

 60:172-176. 



Foy. C. D. 1976. Differential aluminum and manganese toler- 

 ances of plant species and varieties in acid soils. Ciencia E 

 Cultura 28:150-115. 



Gausman. H. W.. A. H. Gerbermann. and C 1. Wiegand. 



1975. Use of ERTS-1 data to detect chlorotic grain sorghum. 

 Photogram. Engin. and Remote Sensing 41:177-181 . 



Idso. S. B.. R. D. Jackson, and R. J. Reginato. 1977. Extend- 

 ing the "degree day"" concept of plant phenological develop- 

 ment to include water stress effects. J. Theoret. Biol, (in 

 press). 



Idso. S. B.. R. D. Jackson, and R. J. Reginato. 1975. Detec- 

 tion of soil moisture by remote surveillance. Amer. Sci. 

 63:549-557. 



Maas. E. V. and Gen Ogata. 1972. Radial transport of sodium 

 and chloride into tomato root xylem. Plant Physiol. 50:64-68. 



Maas. E. V., Gen Ogata, and M. J. Garber. 1972. Influence of 

 salinity on Fe. Mn. and Zn uptake by plants. Agron. J. 64:793- 

 795. 



Nieman, R. H. and L. L. Poulsen. 1971. Plant growth suppres- 

 sion on saline media: Interactions with light. Bot. Gaz. 132-14- 

 10. 



Shalhevet. J.. E. V. Maas. G. J. Hoffman, and Gen Ogata. 



1976. Salinity and the hydraulic conductance of roots. Physiol- 

 ogia Plant. .38:224-232. 



Thomas. R. 0.. and M. W. Christiansen. 1971. Seed hydra- 

 tion-chilling treatment effects on germination and subsequent 

 growth and fruiting of cotton. Crop Sci. 11:454-456. 



Wiegand. C. L.. and L. J. Bartelli. 1971. Remote sensing for 

 conservation and environmental planning. In: The shape of 

 things to come. Soil Conserv. Soc. Amer. Proc. 26:231-240. 



Weimberg. R. 1970. Enzyme levels in pea seedlings grown on 

 highly salinized media. Plant Physiol. 46466-470. 



Weimberg, R. 1975. Effect of growth in highly salinized media 

 on the enzymes of the photo-synthetic apparatus in pea seed- 

 lings. Plant Physiol. 56:8-12. 



10 



AGRICULTURE 



