WALNUT BREEDING

The present Italian walnut industry, is based entirely on the autochthon cultivar Sorrento, that has many good traits, but some defects too: early leafing, only medium nut and kernel quality, bad adaptability to other environments.

The breeding program was started in 1980, in order to obtain new cultivars more productive and with superior fruit quality traits; the following interesting characters were selected among the cultivars of the variety testing trial:

medium-late leafing time, homogamy, high percent of fruitful lateral buds, early bearing, resistance to Xanthomonas juglandis, reduced tree size, high kernel-shell ratio, high quality of nut and kernel.
During 1980–1983, the following controlled crosses have been made: Sorrento x Serr, Sorrento x Payne, Sorrento x Pedro, Sorrento x Tehama, Sorrento x Chico, Sorrento x Gustine, Sorrento x Midland, Hartley x Sorrento, Franquette x Sorrento, Franquette x Serr.

A total number of 2500 seedlings has been obtained and planted, spaced m 5 x 3.

Up to 1985, no fruits were produced; 85 percent of surviving plants has been recorded at the second year.

A field selection form has been prepared.

The first selection is scheduled after the second crop.

I International Symposium on Walnut Production

G. Tamponi

https://doi.org/10.17660/ActaHortic.1990.284.23