¹⁵N IN FRUIT TREE NUTRITION

Young apple trees of cultivar Golden Delicious growing in pots in the greenhouse and young tart cherry trees of cultivar Schatenmorelle growing in sand in the field were treated in September with ¹⁵N-labelled urea.
The following treatments were used:

1. Ground application

2. 4 per cent urea solution application on the leaves

3. 8 per cent urea solution application on the leaves

During dormancy, on 8 February of the next year, i.e. 4–5 months after treatment whole trees were removed from soil and divided into their component tissues.
In these tissues the total nitrogen and ¹⁵N abundances were determined.

The results obtained showed that, in the case of tart cherry trees, 39–47 per cent of the urea nitrogen brushed on the leaves was absorbed and translocated from them to the tree before leaf fall.
The highest recovery of nitrogen (47 per cent) followed leaf application of 4 per cent urea solution and the lowest (25.5 per cent) followed ground application.
In apple trees about 42 and 44 per cent of the applied nitrogen was found in the trees following leaf application of urea in 4 per cent and 8 per cent solutions, respectively, whereas ground application resulted in a 43 per cent recovery of fertilizer nitrogen.

Symposium on Mineral Nutrition and Fruit Quality of Temperate Zone Fruit Trees

K. SLOWIK, D. SWIETLIK

https://doi.org/10.17660/ActaHortic.1980.92.26