陕西渭北地区苹果树腐烂病发生情况调查

为明确近年来陕西省苹果主产区腐烂病发生动态,于2009-2011年在渭北7个县区对不同树龄、不同品种的525个苹果园进行系统调查。结果表明,这些果园苹果树腐烂病发生普遍,平均病株率55%、单株平均新生病疤数1.5个、病情指数25、侧枝发病率14%,年份间除侧枝外,其他发病率没有明显性差异。不同树龄的富士苹果树发病情况调查显示,其平均侧枝发病率、病情指数差异显著,树龄大发病严重,16～20a树龄比6～10a树龄的果园发病率和单株平均新生病疤数分别高出58.89%和46.21%;富士、嘎啦和秦冠3个品种发病情况调查显示,其平均侧枝发病率差异显著,以秦冠发病最轻,且平均病株率和病情指数也明显低于其他品种;不同地域富士发病情况差异显著,渭北台塬西部区的腐烂病发生最为严重,渭北台塬东部区次之,渭北高原沟壑区发病最轻;栽植密度对富士果园发病影响显著,栽植密度大的果园其平均病株率、单株平均新生病疤数、病情指数、侧枝发病率均明显高于栽植密度小的果园。

Survey of Apple Valsa Canker in Weibei Area of Shaanxi Province

In order to know the occurrence of the apple valsa canker in Weibei area of Shaanxi, apple trees of different ages and cultivars from 525 orchards in seven counties were surveyed in 2009, 2010 and 2011. The results showed that the incidence of apple valsa canker in Weibei area was about 55%, average number of the new scars per tree was 1.5, disease index was 25, diseased lateral branches rate was about 14%, these all indicated the disease was prevalent and serious in this area. There is no significant difference among different years except the rate of diseased lateral branches. Tree age has a significant difference on the diseased lateral branches rate and disease index. And the incidence increased as trees got older, the disease incidence and the average number of the new scars per tree for the trees at the age of 16-20 years were 58.89%, 46.21% higher than these of the trees at the age of 6-10 years. There was significant difference of diseased lateral branches rate among different cultivars, Qinguan had lower disease incidence and disease index than other cultivars. Greatly difference was indicated for Fuji among different regions. The disease in the West part of Weibei loess tableland was the most serious compared with other regions. The planting density affected the disease occurrence of Fuji greatly. The disease incidence, average number of the new scars per diseased tree, disease index and diseased lateral branches rate were all increased as the planting density got thicker.