NGHIÊN CỨU ẢNH HƯỞNG CỦA VIỆC TRỒNG XEN ỔI TRONG VƯỜN CAM ĐỂ KIỂM NGHIỆM SỰ HẠN CHẾ RẦY CHỔNG CÁNH (Diaphorina citri Kuwayama)- MÔI GIỚI LÂY TRUYỀN BỆNH VÀNG LÁ GREENING

Intercropping guava in citrus orchards in order to test the control of the population density of Asian Citrus Aphids (Diaphorina citri Kuwayama) - a transmitting vector of the Greening disease to the citrus, and preventing the Greening disease re-infection in the orchard by disease-free seedlings is strategically important to the effective production and extended lifetime of orchards. The Center for Research and Development of Citrus conducted the program titled "Research on technical measures of intercropping guava in orange orchards in Cao Phong - Hoa Binh and Ba Vi - Ha Noi" from 2009 to 2011. Primary achievements are as follows: - The density of aphids (Diaphorina citri Kuwayama) in orange-Xa Ly guava transcropped orchards has been remarkably lower than in those orchards without intercropping. - Diaphorina citri Kuwayama has been found in all months of observation, however higher frequency of appearance has been seen in March, April, May, June and September as coincidence with the times when the Xa Doai Orange formed buds. - The rate of greening disease infection in orange orchards which are intercropped with Xa Ly guava was remarkably lower compared to the orchards with no intercropping, (the percentage of positive disease samples in guava-intercropped orchards was 16.67% while in un-intercropped ones was 36.67%).