DWARFING ROOTSTOCKS SELECTION FOR PRUNUS DOMESTICA. PRELIMINARY TRIALS

Seedlings of several species of Prunus and several clones of inter-specific hybrids were tested as rootstocks of French Prune, clone GF INRA 707. Important differences in tree development were observed after eight years in orchard.
Some rootstocks seem, after three successive crops, more promising for different reasons; they show a high productivity index during the first years.
They are:

• For mean vigor: the hybrid clone F₁(P 322 x P 871)1 which is Belsiana crossed by a natural hybrid Myrobolan x peach. (Cross section of trunc: 150 cm2).

• For weak vigor: seedlings of Prunus Hortulana. (Cross section of trunc: 90 cm2).

• For a very weak vigor: seedlings of Prunus Tomentosa. (Cross section of trunc: 40 cm2).

• For a true dwarfing stock: the hybrid clone P 2038 which is a natural hybrid between Prunus Besseyi and an unknown diploid Prunus. (Cross section of trunc: 25 cm2).

For this trial the control was a clone of Myrobolan (cross section of trunc: 200 cm2).

Clones F₁ (P 322 x P 871)1, P 2038 and seedling of Prunus Hortulana improved the size of fruits.

In nursery, the clone F₁(P 322 x P 871)1 has good performances.
Scions are vigourous, his compatibility is good also with Japanese plum (cv.
Methley), with almond (cv.
Ardèchoise) and with apricot (cv.
Polonais and Canino).

French Prune scions budded on rootstock P 2038 show a weak union in spring.
Other varieties (Green Gage, Prune Peche, Utility) budded on the same rootstock show better union.

Symposium on Plum Genetics and Plum Breeding

R. Bernhard, Y. Mesnier

https://doi.org/10.17660/ActaHortic.1975.48.2