THE EFFECT OF CROPPING AND NITROGEN LEVELS ON CANOPY DRY MATTER DISTRIBUTION IN SOUR CHERRY (PRUNUS CERASUS)

Growth and dry matter accumulation were measured in different parts of three-year-old potted sour cherry (Prunus cerasus) ‘Stevnsbaer’ at low and high cropping levels.
Reducing the crop level to less than 50 % increased the number of, and dry matter accumulation in, leaves and shoots relatively little (less than 28 %) with a trend towards thicker shoots (1993) and longer shoots or larger leaves (1994). Compensatory dry matter accumulation in perennial parts was probably small as well.
Total dry matter accumulation until fruit harvest was lower at a low cropping level.

However, when vigour was increased by increasing the nitrogen supply, a nearly complete compensation occured at a low crop load, emphasizing longer shoots and larger leaves.
Efficiency of leaves was reduced to 60 – 70 % at a low, compared to a high, cropping level.
Leaves produced up to 10 x their own weight and harvest index approached 50 % of the dry matter accumulated until fruit harvest.

The importance of considering not only the sink strength of fruits, but also the effect of vegetative vigour, on partitioning of growth and dry matter is discussed.

III International Cherry Symposium

T.B. Toldam-Andersen, P. Hansen

Growth compensation, nitrogen, source-sink, vigour, carbohydrate partitioning

https://doi.org/10.17660/ActaHortic.1998.468.67