P. Spiegel-Roy
Most of the apricot trees planted recently in Israel are of the Canino variety. This variety shows definite uncompatibility on the almond root, and nearly all trees are on apricot seedling rootstock.

During the first years after planting few, if any decline symptoms were noted; the variety has shown remarkable adaptability, vigor and fertility. Lately, decline symptoms and die-back of trees have become noticeable in some areas, with an increased frequency in the number of trees showing decline symptoms.

In the northern region with its relatively higher winter precipitation, some young trees began to show serious decline symptoms after earlier, vigorous growth. Usually during the second or third summer after planting, the trees start to show symptoms as if suffering from drought (in spite of sufficient irrigation water applied during summer): a profuse amount of gum exudes from the bark; the leaves turn yellow and drop prematurely; the fruit is often distorted, with black spots in the flesh which are often visible externally. Leafing out during the following spring is nearly normal. However, during the next summer the same symptoms reappear, with increasing severity; many of the affected trees decline and ultimately die. Often, necrotic spots in the xylem of the trunk accompany the decline symptoms, with occa-

Spiegel-Roy, P. (1968). DECLINE SYMPTOMS WITH CANINO APRICOTS. Acta Hortic. 11, 561-564
DOI: 10.17660/ActaHortic.1968.11.55

Acta Horticulturae