Bài báo này là công bố đầu tiên về nguyên nhân gây bệnh chết rạp trên cây con ba kích ở Việt Nam. Để nắm chi tiết nội dung nghiên cứu bài viết. | Nghiên cứu tác nhân gây bệnh chết rạp cây con ba kích Morinda officinalis How. tại Việt Nam Kết quả nghiên cứu Khoa học BVTV - Số 6 2019 NGHIÊN CỨU TÁC NHÂN GÂY BỆNH CHẾT RẠP CÂY CON BA KÍCH Morinda officinalis How. TẠI VIỆT NAM Study on The Pathogen Causing Damping - off on Indian Mullberry Morinda officinalis How. in Viet Nam 1 1 2 1 Chu Thị Mỹ Đặng Thị Hà Đào Thị Kim Nhung Lê Thị Thu 1 1 Hoàng Diệu Linh amp Phan Thúy Hiền Ngày nhận bài Ngày chấp nhận Abstract Indian Mullberry Morinda officinalis How. locally known as ba kich belonging to the Rubiaceae family commonly grown in Viet Nam for medicinal purposes. However ba kich seedlings in the nurseries are sufferred from the attack of damping-off disease. The objective of the present study was to characterize the causal pathogen of the damping-off disease of ba kich. Surveys were conducted in different ba kich nurseries in Thanh Hoa and Bac Giang provinces from March to July 2018 and a number of 3 to 4 month old seedlings showing symptoms of damping-off disease were collected for further identification. In the surveyed nurseries the incidence of damping-off disease was above 50 . Disinfected collar segments about 5 mm in length were plated on quarter strength PDA mPDA and the isolated fungus was cultured on PDA and incubated at 25 C. Rhizoctonia solani was consistently isolated from the infected tissues. The colony growth was 90 mm after 3 days on PDA sclerotia were produced after incubation from 5 to 7 days. The optimal conditions for the development of R. solani o o were 25 C to 30 C and pH 7. The efficacy of azoxystrobin difenoconazole Amistar top 325 SC and validamycin A Vanicide 5 SL in reducing R. solani mycelial growth was tested in vitro. The results indicated that azoxystrobin difenoconazole Amistar top 325 SC is highly effective in inhibiting the mycelial growth of R. solani. This is the first report of R. solani causing damping-off disease of ba kich in Viet Nam. Keywords Morinda
