Abstract: A field experiment was conducted to examine the effects of different cultivation modes on diseases and insect pests in lotus field. There were four treatments, including lotus-turtle-turtle-fish co-cultivation (JGBY), lotus-turtle-fish cocultivation (JGY), seed lotus monoculture (JCK), and seed lotus ecological planting (JCK0). The results showed that compared with JCK0, the control efficacy of JGBY, JGY, and JCK on lotus brown rot was 21.3%, 20.8% and 42.5%, respectively, at the time with the greatest difference of the incidence among all treatment modes. The control efficacy of JGBY, JGY, and JCK on leaf blight was 17.7%, 16.4% and 37.6%, respectively, and that on lotus root rot diseases was 7.7%, 6.4% and 27.5%, respectively. The control efficacy of JGBY on main diseases was better than that of JGY, but was not as good as that of JCK. At the peak occurrence of each pest, the control efficacy of treatments on Donacia provosti and Pomacea canaliculata was the best. Compared with JCK0, population density of Donacia provostii under JGBY, JGY, and JCK decreased by 76.9%, 46.2%, and 84.6% respectively, while population density of golden apple snail decreased by 69.2%, 53.8% and 46.2% respectively. The control efficacy of treatments on Donacia provosti and Pomacea canaliculata were as follows: JGY < JGBY < JCK, and JCK < JGY < JGBY. JGBY and JGY can play a stable and continuous role in the prevention and control of the damage of Donacia provostii and Pomacea canaliculata. However, the control efficacy on Rhopalosiphum nymphaeae and Spodoptera litura was not as good as that of JCK treatment, which should be combined with chemical control. Compared with JCK, JGBY and JGY treatment modes can reduce the amount of pesticides and fertilizers, reduce environmental pollution, and improve ecological and economic benefits.

Key words: seed lotus, Chinese soft-shell turtle, Chinese pond turtle, hybrid crucian carp, pest and disease, economic benefit