Freezing Injury Diagnoses and Preventing Frostbite Technology Methods About Citrus in Shaoguan Region

On the last ten days of December in 1999, citrus fruit trees frostbited in varying degrees with low temperature and frost injury in Shaoguan region.Shatian pomelo that is main plant variety frostbited on class 2 or 3 and Wenzhou oranges on class 1 or 2,and some trees died,too.The main causes are that the low temperature came early,the temperature dropped greatly,and the trees werent pruned in time after freezing injury.This paper introduces the preventing frostbite technology methods and renewing measurements after freezing injury about citrus,such as bundling bole,whitening,covering with grass below trees,fuming,pruning in time,fostering and managing.