金优253免耕抛栽秧苗的根系生长与立苗特性

2003年早季和晚季在大田条件下．以常耕抛栽为对照．对金优253免耕抛栽秧苗的根系生长与立苗特性进行了研究。结果表明，与常耕抛栽秧苗相比，免耕抛栽秧苗前期立苗速度较慢，后期立苗速度较快，总的立苗时间相同，但免耕抛栽秧苗的立苗更易受不良气候的影响；免耕抛栽秧苗立苗期发根较多．但根系生长受阻，根系的总长度不及常耕抛栽秧苗；抛后1周内，抛栽秧苗根系活力经历了由低到高再到低的变化过程。当根系活性上升时，免耕抛栽秧苗上升速度慢；当根系活力下降时．免耕抛栽秧苗下降也慢。

Root growth and standing characteristics of Jinyou 253 seedlings under no-tillage with cast transplantation

In the early and late seasons of2 0 0 3,with Jinyou2 53as material,field experiments were conducted to study root growth and seedling standing characteristics of no-tillage and cast transplanting rice( NTCTR) .Results showed that,compared with conventional tillage and cast transplanting rice( CTCTR) ,NTCTR s standing was slower during early period,faster during late period,butthe total standing time wasnotdifference. However,the influence by bad weatherduring seedling standing of NTCTR was greater. NTCTR produced more roots during seedling standing period,butshorter roots due to its slow roots growth.Rootactivities of casttransplanting rice had changes from low to high to low during one week after transplanting,butroot activities of NTCTR revealed slowly change not only during rising period butalso during falling period.