Intercropping of rice varieties increases the eff iciency of blast control through reduced disease occurrence and variability  

作　　者：HAN Guang-yu LANG Jie SUN Yan WANG Yun-yue ZHU You-yong LU Bao-rong 

机构地区：[1]The Key Laboratory for Agro-biodiversity and Pest Control, Ministry of Education,College of Plant Protection, Yunnan Agricultural University [2]Key Laboratory for Biodiversity Science and Ecological Engineering, Ministry of Education,Institute of Biodiversity Science, Fudan University

出　　处：《Journal of Integrative Agriculture》2016年第4期795-802,共8页农业科学学报（英文版）

基　　金：funded by the National Basic Research Program of China (2011CB100401)

摘　　要：Creating a crop-heterogeneous system by intraspecific mixtures of different rice varieties can substantially reduce blast diseases. Such variety mixtures provide an ecological approach for effective disease control, maintaining high yields with the minimum fungicide applications. Whether such an approach is universally applicable for random rice variety combinations and what is the variation pattern of the diseases under intercropping still remains unclear. We conducted two-year large-scale field experiments involving 47 rice varieties/lines and 98 variety-combinations to compare the occurrence of rice blast in monoculture and intercropping plots at multiple sites. In the experiments, the plant height of the selected tradi- tional varieties was about 30 cm taller, and their life cycle was 10 days longer, than that of the improved rice varieties. The monoculture included either traditional or modern rice varieties grown in separate plots. The intercropping included both traditional and modern rice varieties planted together in the same plots. Results from the field experiments under natural disease conditions demonstrated significant reduction for rice blast disease in intercropping plots, compared with that in monoculture plots. For traditional varieties, the average blast incidence reduced from -26% in monoculture to -10% in intercropping, and the disease severity reduced from -17 in monoculture to -5 in intercropping. For modern varieties, the average blast incidence reduced from -19% in monoculture to -10% in intercropping, and the severity from -10 in mono- culture to -4 in intercropping. Traditional rice varieties （-72%） had a much greater increase in the efficiency of disease control than modern varieties （-60%）. In addition, substantially lower values of variance in the blast incidence and severity was detected among the variety combinations in intercropping plots than in monoculture plots. Based on these results, we conclude that the intercropping or mixture of rice varieties greatly reduces the oCreating a crop-heterogeneous system by intraspecific mixtures of different rice varieties can substantially reduce blast diseases. Such variety mixtures provide an ecological approach for effective disease control, maintaining high yields with the minimum fungicide applications. Whether such an approach is universally applicable for random rice variety combinations and what is the variation pattern of the diseases under intercropping still remains unclear. We conducted two-year large-scale field experiments involving 47 rice varieties/lines and 98 variety-combinations to compare the occurrence of rice blast in monoculture and intercropping plots at multiple sites. In the experiments, the plant height of the selected tradi- tional varieties was about 30 cm taller, and their life cycle was 10 days longer, than that of the improved rice varieties. The monoculture included either traditional or modern rice varieties grown in separate plots. The intercropping included both traditional and modern rice varieties planted together in the same plots. Results from the field experiments under natural disease conditions demonstrated significant reduction for rice blast disease in intercropping plots, compared with that in monoculture plots. For traditional varieties, the average blast incidence reduced from -26% in monoculture to -10% in intercropping, and the disease severity reduced from -17 in monoculture to -5 in intercropping. For modern varieties, the average blast incidence reduced from -19% in monoculture to -10% in intercropping, and the severity from -10 in mono- culture to -4 in intercropping. Traditional rice varieties （-72%） had a much greater increase in the efficiency of disease control than modern varieties （-60%）. In addition, substantially lower values of variance in the blast incidence and severity was detected among the variety combinations in intercropping plots than in monoculture plots. Based on these results, we conclude that the intercropping or mixture of rice varieties greatly reduces the o

关 键 词：Oryza sativa cropping system disease suppression disease variation mixed-planting pure-planting cropheterogeneity 

分 类 号：S435.11[农业科学—农业昆虫与害虫防治]