To study the response of date palm trees to Fe fertilization, two date palm cultivars, Khlas and Ruzaiz, were fertilized with different levels of FeEDDHA (trunk injected and through soil) and FeSO4 · 7H2O(trunk injected). Leaves were collected 100 days after iron application and analyzed for micronutrients. The injection with 100 g FeSO4 · 7H2O/tree increased the Fe contents in the leaves of both cultivars, and with 100 g FeEDDHA/tree in the leaves of Ruzaiz cultivar. Soil application of FeEDDHA was not effective. The contents of Cu, Mn and Zn in the leaves were not affected by Fe fertilization.

No abstract

No abstract

From 1974 to 1977 the heavy metal content of river water, fishes (Salmo trutta fario), three aquatic plants (Cladophora glomerata, Potamogeton pectinatus, Zannichellia palustris), one river-bank plant (Phalaris arundinacea), and sediments (clay fraction) taken from the River Leine, up and downstream of Göttingen, were determined. Galvanic-bath sewage containing heavy metals caused an increase (11-60%) in the concentration of nine elements in the water. The average level of heavy metals in the river water corresponded to that of the Ems, Elbe and Weser, but was lower than that of the Neckar, Rhine and Danube. It was also below the European Community Guidelines (1975) on the quality of water used for the artificial recharging of ground water. River water upstream of the city has been used for this recharging for many years. There is a good correlation between the metal content in the investigated samples and in the water. In the muscles, only Cd, Co and Mn, in the liver Cd, Co, Cr. Hg, Mn and Zn, and in the total fish Cd, Co, Cr, Cu and Zn had increased significantly. In contrast to all other elements, Cr shows the highest concentration in the muscles. A previous accumulation of Cr in the liver is not a prerequisite for the accumulation in the muscles. Mercury shows the highest accumulation in the muscles, apparently because of the high retention rate of this element. Muscles also are a good monitor for this element. The impact of heavy metals on the Leine water was reflected in aquatic plants, which showed an increase in concentration up to 95-fold (according to metal or plant) - but not in river-bank plants. C. glomerata has the remarkable capability of accumulating all ten elements. Since P. arundinacea cannot reflect the different load of heavy metals it is therefore less suitable as a biological monitor for these metals.(ABSTRACT TRUNCATED AT 250 WORDS)

No abstract