Rain forecast for early this week should help to encourage growth of young oilseed rape plants on thinner soils where the surface soil had just started to dry out. Some growers are applying a low dose of N while temperatures remain sufficiently high for the plant to make use of it. Once we get into October a “fire engine” dose of N is less effective.
On more moisture-retentive soil the rape is growing strongly and has reached the four leaf stage. Blackgrass is also developing well and needs early treatment. Normally at this stage a low dose propaquizafop would be applied to control volunteers, with blackgrass control following later. This year, in many cases, both jobs will be done in one, using Laser or Aramo.
There was little sign of slugs in rape crops at emergence but they are beginning to show up now. Backward crops in particular need careful monitoring, as patches of crop can disappear overnight. Where pelleting is necessary, remember that there is a maximum limit of 210gm/ha for a single dose of metaldehyde.
Cereal drilling commenced last week and seed-beds are mostly very good. The majority will be treated pre-emergence with flufenacet mixtures to start off the weed control. There is now so little choice for post-emergence blackgrass control in winter barley that a pre-emergence treatment should be considered essential. Warm, moist soils will produce very rapid crop emergence so pre-emergence sprays should be applied very soon after drilling. Glyphosate can be added where necessary to control weeds that have survived in the seed-bed.
Slugs will be active especially following break crops so regular monitoring is needed as the new crop emerges. If test baiting use layers mash and not slug pellets.