Articles
APRICOT BREEDING FOR THE EASTERN UNITED STATES OF AMERICA
In northern growing areas low winter temperatures damage flower buds and vegetative parts.
Warm, humid summers favor development of diseases including bacterial leaf spot (Xanthomonas pruni (EFS) Dow.), gummosis (Cytospora sp., and Pseudomonas syringae Van Hall), and brown rot (Monilinia fruticola (Wint.) Honey.), Fluctuating spring temperatures with associated frosts are a problem in all but the most northern areas.
The eastern US is a potential apricot producing region with ready access to large metropolitan markets.
Climatic limitations for apricot culture in this area are a combination of low winter temperatures in the northern section, high winter temperatures in the southern section, and fluctuating spring temperatures and warm, humid summers throughout the region.
Spring frosts may be the limiting factor for apricot culture in much of the East, especially in the mid-Atlantic states which include Delaware, Maryland, New Jersey, North Carolina, Virginia, West Virginia, and portions of New York and Pennsylvania.
Changes in the oscillation of upper atmospheric wind patterns during the early spring cause polar continental air from northern Canada and tropical maritime air from the southeast to interplay over this area bringing rapid and dramatic changes in temperature and precipitation (Fig. 1).
Escape from spring frost may be achieved through a requirement of prolonged periods of cold (chilling) temperatures during winter for flower development, or a high heat requirement for flower development in spring.
These characteristics are inherited independently (Bailey and Hough, 1975). The ultimate goal is high-chill, high-heat requiring cultivars for the northeast and mid-Atlantic areas and cultivars with lower chill requirements but very high-heat requirements for southerly areas with cool winters.