Response of Exotic Invasive Weed Alternanthera philoxeroides to Environmental Factors and Its Competition with Rice

• Published in: Rice science 2007-03, Vol.14 (1), p.49-55
• Main Authors: YU, Liu-qing, FUJII, Yoshiharu, ZHOU, Yong-jun, ZHANG, Jian-ping, LU, Yong-liang, XUAN, Song-nan
• Format: Article
• Language: English
• Subjects: Alternanthera philoxeroides; competitive ability; environmental factor; hydrophytic type; rice; viability; 喜旱莲子草; 外来入侵杂草; 水花生; 环境因子; 竞争力
• ISSN: 1672-6308; 1876-4762
• DOI: 10.1016/S1672-6308(07)60008-0

A greenhouse experiment was conducted to determine the influence of the environmental factors such as low-temperature, drought stress, salt-alkali and flooding on the survival rate, propagation rate, fresh biomass and viability of the Altemanthera philoxeroides and its competitive ability against rice by using bioassay method. A high viability of 84% was found when the stems were treated at 4℃ and then grew under normal conditions, while no viable plant was noted when the stems were treated at -20℃ and grew under normal conditions. Compared to the fresh stem with water content of 93.5%, the survival rate, number of propagated stems and fresh biomass of A. philoxeroides derived from the stems with water content of 30.2% were reduced by 45%, 33% and 74% respectively. The treatments of 0.1% salt-alkaline solution led to loss of viability of A, philoxeroides. The stems of A. philoxeroides could grow in wet soil with different depths of water-layer. The A. philoxeroides at density of 23-180 plants/m^2 reduced the rice grain yield by 43-50% at the rice plant density of 100 plants/m^2.