Volume 30 Number 1 Article 14 Pages: 15-16
Year 1976 Month 1
Title: Bacterial Spot Resistance in Stone Fruits
Author: C.N. Clayton
Citation
Abstract:
Bacterial spot of peach, nectarine,
apricot and plum, caused by the bacterium
Xanthomonas pruni, affects
fruits, leaves and stems.
This disease
results in heavy loss in humid areas
on trees grown in light sandy soils.
No chemical control measure is effective
under favorable conditions for
disease development.
However, some
cultivars show high resistance to the
disease.
In North Carolina in the Sandhills
area, where favorable conditions
exist for successful peach production,
breeding for improved peach cultivars
with commercial resistance to bacterial
spot has been underway for 25
years.
From the cooperative breeding
program by the Departments of Plant
Pathology and Horticultural Science
the following bacterial spot resistant
cultivars have been named: 'Whynot';
'Candor', 'Rubired', 'Pekin', 'Troy',
'Norman', Winblo', 'Biscoe', and 'Emery'.
None of these are immune to
bacterial spot.
Yet, they have commercial
resistance to the extent that
the fruits are little affected by the
disease.
The progenies from many crosses
between cultivars varying in disease
resistance have been inoculated under
orchard conditions for several years.
For certain crosses the % of seedlings
with average ratings of resistant, moderately suscceptible, highly or very susceptible to bacterial spot indicate that resistance can be obtained readily from crosses of resistant parents.
Several hundred peach selections and 30 or more nectarine selections with bacterial spot resistance are being evaluated for future cultivars.
From present breeding material there is no reason why adequate control of bacterial spot in peach, nectarine, and plum cannot be attained withou relying on relatively expensive ineffective chemicals.
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