刈割对入侵植物少花蒺藜草再生生长及繁殖特性的影响

Effects of mowing on plant regrowth and reproduction characteristics of invasive Cenchrus pauciflorus

为探索有效控制辽西北风沙半干旱区恶性入侵植物少花蒺藜草(Cenchrus pauciflorus)扩散技术,在其严重侵染区开展不同时期刈割控制试验,结果表明,少花蒺藜草在整个生长季里均可保持较高的生长速率,刈割后具有超强的再生能力和明显的季节效应,其中分蘖期和拔节期刈割少花蒺藜草再生生长节律与自然生长的相一致,表现出快-慢-快的生长节律,而孕穗期刈割枝条再生后直接进行生殖生长,没有明显的节律变化。对与少花蒺藜草繁殖特性相关的7个生物学性状指标进行主成分分析,最终可获得2个主成分因子,其累积贡献率为93.07%,其中第1主成分确定为株高因子,贡献率为77.225%,第2主成分为分枝数因子。除分枝数外,不同时期刈割对少花蒺藜草的再生生长及繁殖能力都具有明显抑制作用,能大量减少结实数量,效果最佳的为孕穗期低位刈割,可以在少花蒺藜草防控工作中推广应用。

An experiment was conducted to investigate the effectiveness of mowing on plant regrowth and reproduction characteristics of invasive Cenchrus pauciflorus Benth for controlling this invasive plant in the semi-arid region of northwest Liaoning province. The results of this study showed that C. pauciflorus maintained a high growth rate during the whole growing season and showed a stronger regrowth ability and obviously seasonal effectiveness, indicating that the regrowth rates were same as the similar growth rates with quick-slow-quick rhythm when mowing was carried out at tillering stage and jointing stage, and that mowing at booting stage directly benefited the reproductive growth of C. pauciflorus. From 7 indicators of reproductive characteristics of C. pauciflorus, results of Principal Component Analysis showed that the cumulative contribution of the 2 factors was up to 93.07%, the first component factor was the plant height factor and the second factor was the branch factor. Except for the branch number per plant, this study suggested that the mowing at the different time had obviously control effect on C. pauciflorus reproductive ability by reducing a lot of caryopsis number, and the optimal mowing time was booting stage for control C. pauci florus.