Investigation on Seed Pools of Weeds in Main Tobacco Growing Areas in Sichuan

For effectively controlling weeds in tobacco fields,the seed pools of weeds in main tobacco growing areas in Sichuan was studied in terms of composition and population with germination method in 2011-2014.The results showed that there included 24 weed species,belonged to 15 families,spread mainly in 0-15 cm soil layer.The dominant species were of Gramineae,followed by those of Compositae and then of Chenopodiaceae.The species of dicotyledonous weeds exceeded the species of monocotyledonous weeds in number,but the density of seed was obviously lower.The highest density(19 119 seeds/m²) seed pool was found in the sample from Guangyuan,while the lowest(6 177 seeds/m²) was found in the sample from Panzhihua.