Читать книгу Herbicides and Plant Physiology - Andrew H. Cobb - Страница 24

Most arable weeds germinate in the top 5 cm of soil and this is the region that soil‐acting (residual) herbicides aim to protect. Where minimum cultivation or direct drilling is carried out, the aim is to avoid disruption of this top region of soil in an attempt to minimise weed‐seed germination. A small number weed species can germinate from greater depths and this may be due to these species possessing larger seed. A good example of this is wild oat (Avena spp.), which can successfully germinate and establish from depths as low as 25 cm.

Figure 1.1 Germination periods of some common annual weeds. A greater width of the bar reflects greater germination.

Source: Hance, R.J. and Holly, K. (1990) Weed Control Handbook: Principles, 8th edn. Oxford: Blackwell. Reproduced with permission of John Wiley & Sons.