WALNUT CULTIVARS SUSCEPTIBILITY TO XANTHOMONAS JUGLANDIS

Walnut blight, caused by Xanthomonas juglandis, is one of the major disease in walnut orchards, all around the world.

The bacteria infects male and female flowers, shoots and fruits, causing as final result, the loss of a considerable amount of the crop.
During past years, a noticeable difference was observed on fruit infection, among the cultivars of the collection of I.S.F. of Rome.
In June 86, we decided to check 200 fruits, at random, for each cultivar, observing carefully, each nut individually.

Here below, the results, expressed as percent of infected nuts, in decreasing order.

Cultivar	%	Cultivar	%
NUGGET	97	CHICO	42
VINA	92	UEREKA	39
LOMPOC	89	MAYETTE	39
SERR	75	FRANQUETTE	36
PAYNE	74	WATERLOO	22
GUSTINE	72	GRAND JEAN	21
ALSOSZENTIVANYI 117	65	PARISIENNE	8
MIDLAND	63	SORRENTO	8
TEHAMA	54	MARBOT	7
HARTLEY	53	CORNE	2

As noticed the previous years, the californian cultivars, plus the hungarian selection A 117, have shown a high susceptibility; the french cultivars have shown a medium susceptibility, while the italian cultivar Sorrento has shown to be one of the most tolerant.
This research, will continue in the future years, including records on the collection of Caserta Field Station, in Campania region.

I International Symposium on Walnut Production

G. TAMPONI, G.P. DONATI

https://doi.org/10.17660/ActaHortic.1990.284.42