These two rootstocks are in trial at Appleby and Havelock North and are showing considerable promise. The present emphasis on apple rootstock breeding at East Malling is in the M.27 to M.9 size range and there is some interesting material coming through there. Unfortunately it has not been tested for resistance to woolly apple aphid. The major advantages of quince rootstocks are good precocity and good tree size control. They are tolerant of heavy clay soils and tolerant of collar rot.
Quinces are also very resistant to crown gall and said by some to be very resistant to pear decline.
Poor graft incompatibility is usually overcome by using an compatible interstock e.g. Beurre Hardy, for cultivars such as Beurre Bosc. Cultivars such as Comice and Taylor's Gold are, however, fully compatible with quince rootstocks. Pear Pyrus communis Pear rootstocks are generally slow to come into cropping and tree size is much larger than with trees on quince rootstocks. Clonal material e.g. BP 1 and BP 3, is often difficult to propagate. It shows very good anchorage and compatibility.