The hotter the weather, the greater the infestation of Portulaca oleracea: opportunistic life-history traits in a serious weed
文献类型： 外文期刊
作者： Feng, L. 1 ; Chen, G-Q 1 ; Tian, X-S 1 ; Yang, H-M 1 ; Yue, M-F 1 ; Yang, C-H 1 ;
作者机构： 1.Guangdong Acad Agr Sci, Plant Protect Res Inst, Guangdong Prov Key Lab High Technol Plant Protect, Guangzhou 510640, Guangdong, Peoples R China
关键词： common purslane;Brassica parachinensis;choy sum;adaptation;hot season;opportunist;seedbank;seed germination
期刊名称：WEED RESEARCH （ 影响因子：2.424； 五年影响因子：2.533 ）
ISSN：
年卷期：
页码：
收录情况： SCI
摘要： Portulaca oleracea, an r-strategist, is one of the world's most troublesome weeds. During hot seasons, P.oleracea frequently becomes monodominant in choy sum (Brassica parachinensis) fields in Guangzhou city, southern China. Here, we studied the seasonal dynamics of P.oleracea's germinable soil seedbank, population density and above-ground biomass in choy sum fields that had been cultivated continuously for several years. Using P.oleracea seeds collected from these fields, we tested seed dormancy, survival and germination, seedling growth and generation time. Portulaca oleracea occurred at high levels during the hot season, but its occurrence was low, and the germinable soil seedbank was much greater during the cold season. The weed's opportunistic characteristics allowed it to avoid freezing and to proliferate during optimal conditions. Portulaca oleracea's generation time was very flexible, as short as 31days during the hot season, but longer than 100days during the colder season. Seed dormancy tended to be shorter when the seeds were stored at a higher temperature. At a temperature of 35 degrees C, both seed germination and seedling growth showed advantages over those of choy sum. Storage for oneyear at a temperature of -20 degrees C or burial in a paddy field did not significantly reduce P.oleracea seed germination. Nevertheless, seed storage at a temperature of 15 degrees C and soil coverage of 0.5cm on top of the seeds significantly constrained seed germination. Stale seedbed' and/or coverage of the surface with soil are recommended during the hot season. However, rotation of rice and upland crops is not an efficient method for managing Portulaca oleracea infestation.
- 相关文献
