Effect of different seed-bed treatments on the emergence of white clover and weeds

Abstract

Areas of land which had been ploughed or rotary-hoed were treated with methyl bromide or were left untreated. Seedlings of clover and weeds which subsequently emerged were counted and, following each count, plots were sprayed with herbicide or were rotary-hoed to a depth of 5 cm to kill the seedlings. Initially, higher numbers of white clover seedlings and lower numbers of weeds emerged in the rotary-hoed area than in the ploughed area. Methyl bromide reduced the numbers of weed seedlings, but stimulated the emergence of white clover seedlings, particularly 4–6 months after treatment. Spraying seedlings to destroy them more effectively reduced subsequent emergence than frequent shallow cultivation, although emergence of white clover in the second spring was unaffected by either treatment. Methyl bromide treatment or a herbicide fallow can be effective for minimising weed emergence. For reducing clover seedling emergence, the best treatment is probably a herbicide fallow. Crops sown into a prepared seed-bed should be sown with minimum soil disturbance.

Keywords:

• white clover
• Trifolium repens
• leguminosae
• weeds
• weed control
• cultivation
• methyl bromide