North: Oilseed rape early management

We are just beginning to see some signs of life in OSR crops. New root growth can be found and leaf growth will respond to any rise in temperature. Pigeon damage is mainly confined to the earlier areas where the snow was first to retreat however vigliance is required since there are more relatively small crops than usual.

Harvest 09 was a slow affair and much of the rape area was established towards the middle of September. Most of those crops have a GAI of less than 0.5 but have good root growth so still have good potential but they can’t stand any further set back from pigeon damage. Most weed control was Metazachlor based and has done a satisfactory job.

Where cleavers still exist we will use Galera when conditions warm up later in March. Volunteer cereals and wild oats will be moped up with a graminicide again when warmer conditions prevail. Any early spraying will be for light leaf spot where the autumn application failed to go on. Where brome or blackgrass have not yet been treated the only treatment available from now will be a full rate graminicide when growth begins.

On the East Lothian Arable Monitor Farm an area of OSR wasestablished behind a subsoiler with some interesting results. Thestubbles had an initial pass with a Simba Express to achieve a surfacetilth. The seed was then dropped in bands at 0.5M spacing behind thesubsoiler legs. At the same time approx 100kg/ha DAP (18N 46P) was alsoband applied onto the  seed. A control area had the NVZ max of 30kgN/ha broadcast after sowing and rolling. The effect of getting thefertiliser directly onto the band of seed was very marked with muchfaster initial growth. On late sowings this has given a stronger rootwith a bigger canopy.

Current weather conditions are not overly conducive to earlyapplications of nitrogen. However we will aim to have about 60 kg Nonto the smaller OSR crops by the end of the month. Don’t forgetSulphur with OSR needing about 45 Kg S and cereals 20 Kg S applied byearly stem extension. We need to see warmer conditions before it’snecessary to rush out with nitrogen onto autumn cereals so it willprobably be into early March before we top dress winter barley andwheat.

There are areas where not all of the wheat recieved an autumnherbicide. Wet weather arrived early in November and sprayingopportunities diminished rapidly. On crops where annual meadowgrass isnot yet tillering Chlortoluron will still give reasonable control, butwhere it’s tillering Othello will be the preferred product. On thedisease frount most desicions can wait until mid March with theexception of yellow rust. Farms in the earlier coastal areas will needto keep a close eye out for any early yellow rust activity on varietiessuch as Viscount, Robigus and Oakley.

The days may be getting longer but the surrounding hills still have plenty snow cover so winter is not over in this area yet!! 

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