MANAGEMENT PRACTICES AND NUTRITION IN APPLE TREES

Using a high density orchard consisting of trees of McIntosh and McSpur/ M.26 planted in spring 1974, irrigation, non-irrigation, a normal fertilizer programme and one 50 per cent higher were compared at four different planting densities (1908, 2640, 3030 and 3465 trees per hectare) as one-row, two-row, three-row and five-row-beds. Leaf samples were taken from both terminal shoots and spurs outside and inside the crown.

In 1976 the yield from irrigated plots was higher than non-irrigated ones but in the succeeding two years when the summers were wet a larger crop was obtained from the non-irrigated plots. Yield increased in the dense planting with, in 1978, the highest yield (44 t ha^-1), coming from the five-row-bed with the increased fertilizer rate.

The trees in the plots, receiving irrigation and the additional fertilizer produced less coloured apples than those in the non-irrigated plots and those with the regular fertilizer programme. Trees in the one- and two-row-beds had better colour than those in three- and five-row-beds although there was no effect on fruit size.

The concentrations of nitrogen, phosphorus and potassium in leaves from terminal shoots were higher than those in spur leaves. Calcium, magnesium, manganese and iron showed the opposite trend. The concentration of copper was not affected by sampling position.

Orchard management can modify fruit yield, quality and tree nutrition.