Investigation on Five Diseases and Pests Damaging to Torreya grandis ‘Merrillii’ in Zhejiang

From April 2019 to June 2020, investigations were carried out on diseases and insects damaging Torreya grandis ‘Merrillii’ at 5 different stands in Zhejiang province. The results showed that the main diseases were Chlorella sp., Septobasidium pedicellatum and yellowing of branch. The main pests included Nalepella sp., Odontotermes sp.. In Zhuji Dongbaihu, Chlorella sp. and S. pedicellatum had the most serious occurrence, the former could cause damage to seedling, young and ancient trees resulted in fruit dropping, the later could cause damage to young and ancient trees. The highest incidence (28.33%) of yellowing was occurred in Tonglu county, with the index of infection of 0.07. Nalepella sp. was the most serious in Songyang, with the highest damaging rate of 33.33%. Odontotermes sp. in Suichang was the highest (24.00%).