防舞相间间隔棒
anti-galloping phase-to-phase spacer
林间防治
forestry prevention and cure
Pest control of forests
control in forest
Stand control
林间防治试验
Control trials in forest lands
适期防治
Appropriate period prevention
田间防治
prevention and control in fi eld
field control
早期防治
Early control and prevention
变更报表周期间隔
change report period intervals