Delayed drilling

Drilling

Delayed Drilling

Two dates were employed, 21 September and 23 October with black-grass heads being assessed in June. The results showed a significant decrease in the mean black-grass head counts when drilling was delayed for by one month.

Variety Seed rate (numbers m2) Plant Count m2 (21 September Drill) Yield (t/ha) Plant Count m2 (23 October Drill) Yield (t/ha) Yield Difference (late v early drilling)
Gallant 250 439 7.22 0 11.93 4.71
Solstice 250 527 6.72 12 10.57 3.85
Duxford 250 195 9.54 0 10.22 0.68
Warrior 250 212 9.68 17 10.94 1.26

Table reproduced from Ward et al., (2012) – A demonstration on the effects of winter wheat variety choice, seed rate and sowing date upon control of black-grass (Alopecurus myosuroides).

Delaying drilling from September to October can have a significant effect on the number of black-grass plants, and consequently the number of seeds ready for germination in the subsequent autumn . The benefit from delayed drilling is most pronounced when soils are moist, stimulating relatively early germination of black-grass enabling one or more sprays of a non-selective residual herbicide such as glyphosate.

Taking a simplistic point of view – delayed drilling can reduce yield. However, the extent to which yield is reduced depends on a variety of factors including (but not limited to): black-grass pressure/competition, crop variety and speed of initial establishment. It is due to these combinations of factors that, if there is less black-grass pressure on the crop during establishment (which hopefully should be achieved through delayed drilling) then yield potential may not be reduced and there could even be an increase!

More from Crop