ISHS Acta Horticulturae 726: IV International Symposium on Pistachios and Almonds
NUTRIENT ALLOCATION TO LEAVES, BUDS AND STEMS IN ACCORDANCE WITH DIFFERENT PHASES OF (PISTACIA VERA L.) BIOLOGICAL CYCLE |
| Authors: | H. Mehdi, A.C. Chaabouni, K. Gargouri |
| Keywords: | Pistacia vera, nutrient allocation, organs, pistachio |
| Abstract:
In order to study the pistachio tree requirements during critical period of development, mineral compositions of three organs of adult bearing trees were analysed. For this purpose, current-year leaves, buds and stems from 35 year old trees of Pistacia vera L. c.v. “Mateur” were collected and their nutrient contents were analysed in four periods of biological cycle (spring flush, fruit set, post harvest and dormancy). This study was conducted in the Olive Tree Institute orchard situated at 26 km to the North of Sfax. Samples were collected from three replications of three trees presenting neither deficiency nor toxicity symptoms and were in their “On year”. Results showed that, at early spring, the major nutrients, nitrogen (N), phosphorus (P) and potassium (K), were in their maximum rates in perennial organs (buds and stems) when leaves concentrations in these elements were in their minimum. Such data seems to be related on a possible dilution effect resulting from rapid leaf expansion. In July, the situation was inversed with a rise of leaf N, P and K concentrations when those of buds and stems declined. In November, major nutrient leaves rates declined when the bud and stem ones increased which seems to indicate a translocation from leaves to perennial organs for mineral winter storage. Leaf calcium (Ca) rate decreased continually from April to November whereas the contents of this element in the buds and the stems followed a sinusoidal curve with a minimum in April and a maximum in July. The continual decline of leaf Ca content may be attributed to its important role in cell walls and strengthening the plant structure. | |
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