Agriculturae Conspectus Scientificus, Vol 63, No 4 (1998)

Seasonal Changes in Potassium Concentration of Bearing Plum Shoots


Pages: 243-250


Seasonal changes of K concentration in particular parts of plum shoots cv. Bistrica (bark, wood, buds, leaves and fruits) were observed over two growing seasons. There were two variants in the investigation: control trees, grown in grass without regular pruning or fertilization and the experimental treatment, in which the trees were under improved management.
The biggest change in K concentration occurred in the vegetative and generative buds in the period from the beginning of vegetation until the end of blooming. During this period K concentration was increasing and reached a maximum value at full blooming. Potassium concentration in the wood and bark of the previous year shoots slightly declined in the period from the beginning of vegetation to phenophase white heads and then significantly rose to the time of shoot growth cessation. After that, potassium concentration in the bark appreciably declined to the period of fruit ripening, and slightly increased to the end of vegetation. In the same period potassium concentration in wood tissue successively decreased. A sharp fall in K concentration occurred in the bark and wood of the new growth from the period when the shoot growth ceased to the end of August when it reached its minimum and then gradually rose to the end of vegetation.
The concentration of K in the leaf blade increased to the middle of vegetation and after that decreased to leaf fall. In the petiole potassium concentration was the highest at the time of new shoot growth cessation in May, and then decreased smoothly to leaf fall.
Potassium concentration in whole fruits was the highest in the period when terminal shoots stopped growing. After that, potassium concentration rapidly declined to the middle of the June, and then decreased proportionally to the time of fruit ripening.
The investigation showed that management had no effect on the seasonal tendency and had a little effect on K concentration level. Potassium concentration in leaf petiole of control was significantly greater.


Prunus domestica; cultivar Bistrica; mineral nutrition; potassium; orchard management

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