Its meaning and indicatrix clolny quality and its main culture measure will change when yield from low and middle to high,we must change concept,changing culture measure from amount to quality.

• 当其产量由中、低产进入高产和超高产阶段以后，群体质量内涵、指标及其主要栽培措施发生变化，因此，应更新观念，从数量栽培向质量栽培转变。