Effect on Plant

On soils with a poor potassium status, the occurrence of potassium deficiency depends greatly on the crop that is being grown. Grasses, for instance, have a much greater potassium uptake capacity than lucerne or dover owing to their ramified, finely distributed root systems. Potassium ions owe their importance to their capadty to affect the water volume of plasma proteins, by controlling their water content and their influence on enzymes. 

The transport system of plants requires energy in the form of ATP, the synthesis of which once more involves potassium. Potassium is also known to increase frost resistance and resistance to infection and, according to Edwards (1982), it can also reduce - or at least compensate for - the effects of various stresses caused by temperature, moisture, transpiration, disease, and wind. 

Specific deficiency symptoms (Anonymous 1988) include the following  

For S02, the stomatal pores are the main entry ports to the internal air spaces of plant leaves. Absorption takes place mainly by gaseous diffusion through 

Photochemistry of the OH radical controls the trace gas concentration. The photochemistry of the free hydroxyl radical controls the rate at which many trace gases are oxidized and removed from the atmosphere. Processes that are of primary importance in controlling the concentration of OH in the troposphere are indicated by solid lines in the schematic diagram those that have a negligible effect on OH levels but are important because they control the concentrations of associated reaction and products are indicated by broken lines. Circles indicate reservoirs of species in the atmosphere arrows indicate reactions that convert one species to another, with the reactant or photon needed for each reaction indicated along each arrow. Multistep reactions actually consist of two or more sequential elementary reactions. HX = HQ, HBr, HI, or HF. CxHy denotes hydrocarbons. (From Chameides and Davis, Chem. Eng. News 60 (40) 38-52, 1982. Copyright American Chemical Society.) 

---

Environmental impact studies on NE have been performed. Although undiluted NE inhibits seed growth, no effect on plant growth was observed when exposed to 6, 000 ppm-min of NE and only minor effects were observed at the 60, 000 ppm-min exposure level (41). Exposure of microbial populations to 25% NE in air for seven hours showed normal growth. NE is not an o2one-depleting gas (20). 

Symposium on Earthquake Effects on Plant and Equipment (Vols I and II), Organized by BHEL energy system group Hyderabad, India, and Indian Society of Earthquake Technology, Roorkee, India (1984). 

Why is it difficult to prove that effects on plants in the field observed visually were cause by exposure to air pollution ... 

List examples of air pollution effects on plants that cannot be detected by visual symptoms. 

Technical Specification Optimization EOOS can be adapted to show changes in tech spec status, Wbat-if irulyscs, show the effects on plant risk of removing trains of equipment from service. 

Subsequently, in Chapter 4, we deal with cycles in which the turbines are cooled. The basic thermodynamics of turbine cooling, and its effect on plant efficiency, are considered. In Chapter 5, some detailed calculations of the performance of gas turbines with cooling are presented. 

A risk estimate indicates Uie likelihood of occurrence of the different types of health or enviroinnental effects in exposed populations. Risk assessment should include both liuimn health and environmental evaluations (i.c., impacts on ecosystems). Ecological impacts include actual or potential effects on plants and animals (other than domesticated species). The number produced from the risk characleriznlion, representing the probability of adi crse... 

Considerations for the allocation of funds should include economic and public relations factors. Identical FARs do not necessarily result in equal consequences effects on plant production, public relations, and oilier factors must also be considered. Finally, FARs in excess of 4.0 are not acceptable. 

Essential oils are known to have detrimental effects on plants. The inhibitory components have not been identified, but both alde-hydic (benzol-, citrol-, cinnamal-aldehyde) and phenolic (thymol, carvacol, apiol, safrol) constituents are suspected. Muller et al. (104) demonstrated that volatile toxic materials localized in the leaves of Salvia leucophylla, Salvia apiana, and Arthemisia californica inhibited the root growth of cucumber and oat seedlings. They speculated that in the field, toxic substances from the leaves of these plants might be deposited in dew droplets on adjacent annual plants. In a subsequent paper, Muller and Muller (105) reported that the leaves of S. leucophylla contained several volatile terpenes, and growth inhibition was attributed to camphor and cineole. 

Guderian, R. Tingey, D.T. Rabe, R. In Air Pollution by Photochemical Oxidants Formation, Transport, Control, and Effects on Plants] Guderian, R. Ed Ecological Studies, Vol 52 Springer Verlag New York, NY, 1985 pp 129-169. 

M. Muller. C. Deigele, and H. Ziegler, Hormonal interactions in the rhizosphere of maize (Zea mays L.) and their effects on plant development. Z. Pflanzenernahr. Bodenk. 152 241 (1989). 

P. B. Tinker, The chemistry of phosphorus and mycorrhizal effects on plant growth, Endoinycorrhizas (F. S. Saunders, B. Mosse, and P. B. Tinker, eds.). Academic Press, London, 1975, p. 353. 

A. Hussain and V. Vancura, Formation of biologically active substances by rhizo-sphere bacteria and their effect on plant growth. Folia Microhiologica IPA6S (1970). 

Y. Chen, Organic matter reactions involving micronutrients in soils and their effect on plants. Humic Substances in Terrestrial Ecosystems (A. Piccolo, ed.), Elsevier Sciences B. V., Amsterdam, 1996, p. 507. 

J. Alphei, M. Bonkowski, and S. Scheu, Protozoa, Nematoda and Lumbricidae in the rhizosphere of HordeUmus europaeus (Poaceae) faunal interactions, response of microorganisms and effects on plant growth. Oecologia 706 111 (1996). 

D. E. Crowley. V. Romheld, H. Marschner, and P. J. Szaniszlo. Root-microbial effects on plant iron uptake from siderophores and phytosiderophores. Plant Soil 142 1 (1992). 

Once we know the chemical nature of the allelopathic agents and their effects on plant growth dynamics, as well as on health and environment, we can apply genetic manipulation and biotechnology to develop toxin-resistant plants and to reduce the toxin levels frcm the donor plants. These approaches serve a dual purpose because they contribute to increased agricultural productivity and help to minimize the potential risks on health and environment. 

Data summarizing the effects of the inhibitory weed extracts on sorghum water status was taken from the second trial in each case (Table V). All of these extract treatments had reduced sorghum growth, and all but one had some effect on plant water balance. 

Our research on allelopathy in tall fescue (Festuca arundinacea Schreb.) was begun to determine if growth inhibitors were present, if tall fescue had an inhibitory effect on plants growing in association with it, and finally to identify the chemicals responsible for inhibition. 

Maximal levels for -coumaric and ferulic acids of 30.0 and 6.5 pmol/1 0 g of soil ha e been reported (158) and concentrations of 4 x 10 M and 3 x 10 M, respectively, for these two acids in other soils (161)Other gtudies indicate a similar concentration range of 2.3 x 10 to 10 M for -hydroxybenzoic, vanillic and j>-coumaric acids (169). These levels may be too low to have direct measurable allelopathic effects on plants in greenhouse or growth chamber studies (non-rhizosphere soils, low microbial population). However, in field rhizosphere soils (high microbial population) these levels could be sufficient to influence microbial growth... 

In the meanwhile, the precautionary assumption continues to be used by regulators that there is a linear relationship between the level of radioactivity and the risk of cancer even at very low levels. That has a considerable effect on plant design and costs, but it is difficult to see how this could be changed whilst there is such disagreement within the scientific community". 

De Kok LJ, Maas FM, Stulen I, et al. 1988. Sulfur containing air pollutants and their effects on plant metabolism. Commission of European Communities 11244 620-625... 

---