THE EFFECT OF PLANTING DENSITY OF ‘BRAMLEY’S SEEDLING’ APPLE ON MM.111/M.9 ROOTSTOCKS WITH AN M.9 CONTROL IN SITES SUFFERING FROM APPLE REPLANT DISEASE

Apple Replant Disease (ARD) is caused when an old orchard is grubbed out and a significant pathogen population develops in the soil as the remaining root fragments rot.
New roots from young tees planted into such sites are often attacked by these soil pathogens and suffer accordingly.
MM.111 rootstocks with M.9 interstems are promoted in the British Isles as suitable for replant sites.
Because ‘Brameley’s seedling’ apple is such a vigorous cultivar, it is sometimes claimed that a replant site provides a useful check on ‘Bramley’ growth and is therefore an advantage.
On both clean and replant sites the following densities were planted in 2000; D1 – 7.4×5.4 m (24’×18’) open centre on a short stake, D2 – 5.4×3.6 m (18’×12’) central leader on 2.5 m stake; D3 – 4.9×3.0 m (16’×10’) central leader on 2.5 m stake and the control D4 – 4.3×2.4 m (14’×8’) M.9 central leader.
The accumulated results for 2004-2007 prove that in the case of ‘Brameley’s seedling’, ARD infected ground significantly increased yield compared to the clean ground – 107 vs. 36 kg.
On the clean sites the traditional planting density (D1) produced the lowest yield (16 kg) whilst the M.9 treatment generated the highest yield (61 kg).

IX International Symposium on Integrating Canopy, Rootstock and Environmental Physiology in Orchard Systems

S. Mac an tSaoir, J. Mansfield, G. Cross, R. Harun

Malus × domestica, interstems

https://doi.org/10.17660/ActaHortic.2011.903.89