我县某果场一片成年柑桔树高接换种后日灼严重,发病率高达100％。 据观察,日灼多发生在主干和大骨干枝上,离地2m以内,大多在1m左右。受害处树皮及木质部纵向开裂,裂口数1～8条不等,裂口长20cm左右,最长达120cm。病斑一致朝向西北方,树冠内凸出向阳的分枝处及大骨干枝拱面多被害。 该片柑桔树龄30年以上,主要为甜橙。1991年 A fruit of my county an adult citrus tree high after the sunburn serious, the incidence of up to 100%. It is observed that the sunburn occurred in the backbone of the trunk and more, less than 2m, mostly in 1m or so. Victims bark and xylem longitudinal cracking, cracks ranging from 1 to 8, about 20cm long crack, up to 120cm. Consistent with the lesion toward the northwest, crown protruding branches and the large branches of the arches more victims. The piece of citrus tree more than 30 years, mainly orange. year 1991