South: Thinking about N management

Most decisions on which rape crops are worth saving have nowbeen made. Thin and backward ones will need a completely differentapproach to nitrogen management than forward crops.

Consider using growth stimulants like Route or Quark toencourage more prolific rooting. In contrast to recent years thesecrops will need most if not all their nitrogen applied early on toaid rapid canopy expansion and encourage small plants to branchrather than bolt.

If significant fresh phoma lesions are found on backward cropstreatment is still worthwhile. It’s still on the cool side forGalera (clopyralid and picloram) to work well, but remember the cutoff application point is flower buds visible.

There are some thin and backward barleys around and it’simportant to remember that barley is less able to compensate forsub-optimal tiller numbers than wheat. So a higher nitrogen doseearlier on to encourage further tillering is worthwhile in thesethin crops this year.

Forward wheats are few and far between, the average growth stagebeing GS21. Temperatures are just about high enough to applyAtlantis (iodosulfuron + mesosulfuron) and Pacifica (iodosulfuron +mesosulfuron), but on waterlogged soils aim to wait until activegrowth is seen. Try, if possible, to avoid mixing them either witha growth regulator or chlorothalonil. T0 is still some way off inmost crops.

Spring barley drilling is in full swing, with most cropsreceiving a pre-emergence spray of Stomp (pendimethalin) and Defy(prosulfocarb) at 2 litres/ha plus 3-4 litres/ha, respectively, inblackgrass situations or straight Defy at 2-3 litres/ha in annualmeadow grass situations.

Defy (on a SOLA) applied straight is very crop-safe, but bebeware of shallow drillings with the Stomp mix.

Late winter beans are just emerging as the spring crop isdrilled. Two new herbicide options exist pre-emergence on springbeans. Defy (on a SOLA) and Afalon (linuron) are both welcomeadditions to a previously limited and expensive armoury.

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