多效唑在稻田环境中的动态研究

Dynamic of paclobutrazol in paddy field.

报道了多效唑在稻田环境中的动态试验和样品的分析方法。结果表明:施于土壤表面的药剂随水分逐渐向下移动。移动速度与土壤性质有关。连作晚稻秧苗一心一叶期喷施多效唑药液,前期药剂主要分布在土壤耕作层,并向田水中扩散和被稻苗吸收,施药后第1天稻苗中的药剂残留量最高,稻苗移栽时,土壤和稻苗中的残留量均很低。多效唑性质稳定,降解缓慢,在室内淹水和不淹水的土壤中的半衰期分别为45和22天;在田问降解较快,夏季连晚秧田土壤(小粉土)中的半衰期为5天,田水中为5.6天,稻苗中为3～4天。

The results indicated that residues of paclobutrazol were leaching gradually in soils under laboratory conditions and in field ,and its moving speeds were relative to the physicochemical properties of soil types. The residue was mainly distributed on the soil surface(0-15cm). While paclobutrazol applied at the 2-leaf stage of The late rice seedling,and the rest was dispersed into water and absorbed by the seedling. The residue amount was highest in the seedling tissue the day after application,and then it was very low in the seedling tissue and soil at the day of transplant. The half-lives of Paclobutrazol in flooded and unflooded soils were 45 and 22 days respectively under laboratory conditions. But in the field, the degradation was faster than that in the laboratory ,the half-lives were 5 days in soiKsandy loam),5. 6 days in water and 3--4 days in the seedling tissue.