Effects of rice and Canna indica L. intercropping on rice growth, disease/pest incidence and yield

As an agricultural production pattern, intercropping not only improves biodiversity and the related ecological effects on paddy fields, but also increases agricultural production and economic benefits. This study investigated the effects of rice and Canna indica intercropping on growth, diseases and pests control, and grain yield of rice in a one-year paddy field experiment. The results showed that compared with rice monoculture, rice and C. indica intercropping decreased plant height at late tillering stage and heading stage in the early rice season. It increased leaf chlorophyll content during heading and maturity in the early rice season, and late tillering and maturity stages in the late rice season. The tiller number of rice significantly increased under intercropping by 25.20% and 11.20% at late tillering and heading stages in the early rice season and 26.01% at maturity stage in the late rice season. Besides, rice and C. indica intercropping effectively reduced the incidence of sheath blight and rice leaf folder. At medium and late tillering stages in the early rice season, rice sheath blight disease index was decreased by 35.61% and 19.55%, and also decreased significantly by 24.83% and 16.05% at late tillering and heading stages in the late rice season. At the same time, the rate of leaf-rolling by rice leaf folders were significantly decreased (by 46.35% and 60.31%) at medium and late tillering stages in the late rice season. Meanwhile, rice and C. indica intercropping improved rice yield per unit area by 11.16%. In conclusion, rice and C. indica intercropping was considered as a new eco-agriculture system which promoted rice growth, rice yield and economic benefits, and decreased the incidence of diseases and pests.