The Minimization of Variability in Apples Planted on the Site of a Previous Orchard

Following the grubbing of a mature orchard of Bramley’s Seedling apples an investigation was made into the effects of deep (18 in.) or shallow (9 in.) ploughing immediately after grubbing, and of rich or poor manuring during the ensuing seven-year period of arable cropping, on the restoration of uniformity of the soil and its suitability for further experimentation on apples.

The effects of these treatments were assessed through a study of the variation of an apple indicator crop planted at the end of the period of arable cropping and are discussed in the light of the results previously observed after only three years of arable cropping.

There was some indication of a “distance-from-former-tree-site” gradient in growth which was reduced by either deep ploughing or rich manuring.

The contribution of the residual-pattern effect ot the previous orchard to the total variability of the apple indicator crop was small in comparison with the random component of variability.

Random variation was slightly increased by deep ploughing or rich manuring, offsetting the reduction in intensity of residual pattern so that total variability in size of indicator plants was largely unaffected by cultural treatment.