外来植物黄顶菊(Flaveria bidentis)在棉田的发生规律及其生长特性研究

Germination and Growth Characteristics of Exotic Plant Flaveria bidentis in Cotton Field

黄顶菊为外来潜在的危险植物,可能对入侵地造成严重的生态灾难,被称为"生态杀手"。棉田是黄顶菊较容易侵入的农田之一。了解棉田黄顶菊的发生动态和生长特性,对研究黄顶菊的入侵和生态适应性具有重要意义。每7 d调查1次棉田黄顶菊的萌发数量和株数,每14 d调查1次生长特性,对棉田黄顶菊的种子萌发、密度变化以及黄顶菊的生物量、株高和叶片数等生长特性进行了研究,以探明黄顶菊在棉田的发生规律和生长特性,旨为黄顶菊的综合防治提供理论依据。结果表明:播种后21 d内萌发并成长为成株的黄顶菊数量占最终株数的92.9%;播种后22～69 d种子基本不再萌发;播种后第70 d受到土壤湿度迅速增加的影响,种子大量萌发,但此时萌发的黄顶菊幼苗受到群落环境的影响会在出苗后14 d内死亡,对最终密度没有显著影响。黄顶菊的生物量和株高大部分是在出苗56 d以后形成的,其中,生物量增加了84.1%,株高增加了65.3%;而叶片数大部分是在出苗后56 d内形成的,该期形成的叶片数占最多叶片数的57.9%。可选择种植苗期生长迅速的高秆植物并适当密植或者使用其他替代植物组合来抑制黄顶菊的生长,对其进行生态防治。对黄顶菊发生严重的地块,可轮作花生、大豆、玉米等作物,以便于化学防除。

Flaveria bidentis was a potentially dangerous plant,which maybe cause serious ecological disaster and was called the ecological killer.Cotton field is easier to be invaded by F.bidentis.The research on the germination dynamics and growth characteristics of F.bidentis had significance to understand its invasion and ecological adaptability.The germination and plants were surveyed every 7 days,and the growth characteristics including the biomass,plant height and leaf number were surveyed every 14 days in cotton field in order to clear the occurrence rule and growth characteristics of F.bidentis and enrich the theoretical foundation for IPM.The results showed that the quantity of F.bidentis germinated within 21 days occupied 92.9% of the final amount.It did not germinate 22-69 days after sowing.It germinated 70 days after sowing with the increasing of soil humidity,while the seedlings would wilt within 14 days in the community and could not affect the final density.Most of the biomass and plant height were formed within 56-112 days.The biomass and plant height increased by 84.1% and 65.3%,respectively during this period.The leaf number was formed within 56 days,which occupied 57.9% of the final leaves.The plant that could grow rapidly at seedling stage,the rational close planting and plant vicarious species could be selected to control F.bidentis.Peanut,soybean and maize could be planted as rotation crops in the serious field of F.bidentis in order to chemical control easily.