摘要:

ELECTRON TRANSPORT AND PHOTOPHOS‐PHORYLATION, TOPICS IN PHOTOSYNTHESIS, VOL. 4. Edited by J. BarberTHE MATHEMATICS OF PHOTOSYNTHESIS AND PRODUCTIVITY. Experimental Botany. An International Series of Monographs, Vol. 16. By D. A. Charles‐EdwardsDIFFERENTIATIONIN VITRO. Proceedings of the Fourth Symposium of the British Society for Cell Biology. Edited by M. M. Yeoman&D. E. S. TrumanPLASMALEMMA AND TONOPLAST: THEIR FUNCTIONS IN THE PLANT CELL. Edited by D. Marmè, E. Marrè&R. HertelTHE PLANT COMMUNITY AS A WORKING MECHANISM, Special Publications Series of the British Ecological Society 1. Edited by E. I. NewmanTHE NATURAL COUMARINS: OCCURRENCE, CHEMISTRY AND BIOCHEMISTRY. By R D. H. Murray, J. Mendez&S. A. BrownBIOLOGICAL CONTROL IN CROP PRODUCTION. Edited by G. C. Pap

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11611530

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11611534

出版商:Blackwell Publishing    

年代:1982

数据来源: WILEY

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11611543

出版商:Blackwell Publishing    

年代:1982

数据来源: WILEY

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11611573

出版商:Blackwell Publishing    

年代:1982

数据来源: WILEY

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11611630

出版商:Blackwell Publishing    

年代:1982

数据来源: WILEY

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11611686

出版商:Blackwell Publishing    

年代:1982

数据来源: WILEY

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11611695

出版商:Blackwell Publishing    

年代:1982

数据来源: WILEY

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11611700

出版商:Blackwell Publishing    

年代:1982

数据来源: WILEY

摘要:

AbstractAn increasing literature accounting for various types of experiments indicates that far lower external nutrient concentrations are required by plants than is usually thought to be the case. It is concluded that the ion uptake capacity of the roots, as described by the carrier concept, is high compared to that required for maintenance of the internal concentration. Serious errors in experimental conclusions are associated with insufficient and constant nutrient addition rates. The main errors are caused by non‐steady states of the plants both with regard to the internal nutrient concentrations and the relative growth rate.A dynamic concept has been proposed for direct use as the treatment variable within the range of sub‐optimum nutrition. The nutritional factor is expressed as a flow, the relative nutrient addition rate in laboratory studies and the nutrient flux density in the field. The experimental use of the relative addition rate has led to steady‐state nutrient status and relative growth rate and the interpretation of plant responses which differ fundamentally from accepted views. Thus, for instance, deficiency symptoms disappear, as in natural conditions, when the internal nitrogen concentration is stable, independent of level. The nutrition/growth relationships are very different from those observed when external concentration is varied. The regression line of relative growth rate on relative addition rate passes near to the origin at an angle close to 45 to the axes, which implies that the obtained relative growth rate approximates closely the treatment variable. A striking example of observed differences is the positive effect on nitrogen fixation exerted by high relative nitrogen addition rates compared to the well‐known negative effect of increasing external nitrogen concentration.The application of fertilizer on the basis of the nutrient flux density concept provides the possibility of supplying fertilizers corresponding to the consumption potential of the vegetation and to the natural flux density resulting from mineralization in the soil. Nitrogen utilization is high under such conditions and the resulting feedback of nutrition on the mineralization rate suggests that there will be a long‐term increase in

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11611714

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractA clear correlation between the presence of stomata on both surfaces and factors such as habitat, growth form, and physiology has yet to emerge in the literature. However, certain loose trends with these factors are evident, and these are reviewed along with evidence for hypostomaty as the primitive form. It is proposed that the effect of developing stomata on the upper surface as well as the lower is to increase maximum leaf conductance to CO2. Plants with a high photosynthetic capacity, living in full‐sun environments, and experiencing rapidly fluctuating or continuously available soil water (as opposed to seasonal or long‐term soil water depletion), are identified as deriving an adaptive advantage from a high maximum leaf conductance. The correlation between groups of plants fitting the above conditions and those noted to be amphistomatic is remarkable. Plants not fitting the conditions are found to be largely hypostoma

ISSN:0140-7791    

DOI:10.1111/1365-3040.ep11611750

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY