6 September 1996

Hoeing trial shows significant yield rise

INTERIM results from an Elm Farm Research Centre inter-row hoeing trial in winter wheat sown in 30.5cm (12in) rows at Chapel Farm show yields can be significantly boosted and weed levels cut. The crop, Hereward, sown after a three year ryegrass/white clover conversion ley, had about 133 plants a sq m on March 8. Weed levels and yields from unweeded controls were compared with replicated single, double and triple hoeings in March, April and June.

March produced the best single pass yield benefit at 25.8%. A double pass in March and June increased output by 27.5%, while the triple pass gave 28.5% extra (see table).

Being fresh out of a three-year ley, blackgrass levels were not very high. But there was far more knotgrass and black bindweed than might be expected in a winter wheat crop – probably due to the wide row spacing, say the researchers.

By May, March hoeing had reduced total weed dry matter from 13g/sq m to 5g/sq m, which lifted eventual yield from 5.93t/ha (2.36t/acre) to 7.46t/ha (2.97t/acre).

Lowest weed dry matter at harvest came from March plus April hoeings – 3.01g/sq m against 13.27g/sq m for the unweeded. But the yield of 7.1t/ha (2.83t/ha) was not as good as from a single pass in March. &#42


Chapel Farm inter-row hoeing trial

Hoeing datet/ha(t/acre)

March 87.46(2.97)

April 197.05(2.81)

June 77.28(2.90)

March+April7.10(2.83)

March+June7.56(3.01)

April+June7.41(2.95)

Mar+Apr+Jun7.62(3.03)

Unweeded

control5.93(2.36)