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Untersuchungen zur Reaktionsweise junger Klonfichten (Picea abies (L.) Karst.) auf Trockenstress und Magnesiummangel

The growth of the 5 and 6 year old potted cloned spruces, that receive different amount of magnesium, is investigated during water stress periods in 1989 and 1990. In the two following years, flushing and growth reactions due to watering are studied. Nutrient uptake and clone related differences are part of this investigation. Water stress principally reduces the branch length and the number of the needles. In the two following years, the water stressed spruces flush earlier than the watered spruces. Mg deficiency has little effect on branch growth, but reduces the number of needles considerably. Water stress does not influence the Mg uptake directly. Rewatering after a long water stress period increases the MG contents in the youngest needles, which can be seen as a regreening of the yellowed needles. The continually high growth of the spruces without a braking effect of drougth results in the yellowing of the older needles. Fertilization with magnesium leads to regreening. Clone-specific differences are also recorded. (orig.)SIGLEAvailable from TIB Hannover: RO 2590(114) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekLand Baden-Wuerttemberg, Stuttgart (Germany); Commission of the European Communities (CEC), Luxembourg (Luxembourg)DEGerman