苹果幼树死亡诱因、诊断与防控

对矮砧苹果新植苗木和2~5年生幼树死亡的原因进行研究,表明苗木失水与轮纹病菌协同危害是主要原因;冻害、根部与主干病害、肥害及苗木质量差是重要原因。生产上及时发现问题,根据不同症状,进行准确的病因诊断,有针对性地采用不同的防控措施:培育不潜带轮纹病菌的苗木;苗木贮运、栽植和管理过程防止失水;栽植前用杀菌剂铲除部分病菌;防止冻害;2~5年生幼树合理肥水管理;防止贪绿徒长;有效地预防根部和枝干病虫害发生。

Causes,diagnosis and control of death of young apple trees

The causes of death of young apple seedlings and 2-5-year-old seedlings were studied.The results showed that the synergistic damage of seedlings’water loss and Botryosphaeria dothidea was the main cause of death of newly planted apple trees.Freezing damage,root and trunk diseases,fertilizer damage and poor seedling quality were also important reasons for the death of young apple trees.To cultivate high-quality seedlings without the pathogen of B.dothidea,fungicides were used before planting to eradicate parts of the latent pathogens on seedlings.The prevent water loss of seedling during the storage and planting.Management of newly planted young trees were also important technical measures for young apple trees.Selecting suitable seedlings according to local conditions,preventing freezing damage with rational fertilizing and watering,preventing green growth and early defoliation,and timely controlling diseases and pests of root and branch were important technical measures to prevent the death of young apple trees in 2~5 years.In cultivation,problems should be found in time,causes should be diagnosed accurately,and targeted measures should be taken quickly.