THE RESPONSE OF BRAMLEY’S SEEDLING APPLE TREES GROWN ON DIFFERENT ROOTSTOCKS TO SPRING AND AUTUMN APPLIED NITROGEN

Four rates of spring N and three autumn N treatments were applied annually for a five year period to Bramley’s Seedling apple trees grown on M9, M26 and MM106 rootstocks.
The soil management system was grass alley with herbicide treated tree row.
Fertiliser N did not influence yield of trees on M9 and M26 rootstocks but reduced yield on MM106 rootstocks.
Increasing rate of N had no effect on girth increase or extension growth.
Foliar sprays of urea applied after harvest had no effect upon yield or growth.
Leaf N concentration was lowest on MM106 indicating that rootstock is an important factor which should influence the interpretation of leaf N concentration.

Increasing N increased N concentration and tended to reduce P concentration in leaves and fruits.
Although greenness of fruits was positively correlated with fruit N concentration there was no significant effect of N treatment upon fruit colour.
Similarly N rate did not influence fruit firmness or incidence of storage disorders.

There were significant differences between rootstocks in mineral composition of leaves and fruits and incidence of bitter pit after CA storage.

International Symposium on Diagnosis of Nutritional Status of Deciduous Fruit Orchards

M.J. Marks, L. Andrews

https://doi.org/10.17660/ActaHortic.1990.274.40