March 2009 Archives

After what seems to have been an interminably long winter things finally seem to be waking up.

Crops are going through a sort of adolescent phase where anything forward has really got moving, but anything backward is still asleep. This has the effect of making the difference between the two look even greater. But I have confidence that, provided there is a plant, the two will soon even up. Anyone with teenage offspring will know exactly what I mean.

For early-drilled winter crops that established well, the winter has been brilliant. Growth stages are about right for the time of year and disease levels are low. Autumn grassweed control has, on the whole, been very effective and few problems have re-emerged yet. Even for later-drilled crops we have not been chasing weeds, so there is something to say for a proper winter.

Some winter rape crops are just about ready for a stem extension fungicide and some, but not many, will need growth regulation. Some have had their growth regulated and disease controlled by pigeons/rabbits/partridges and some have been ripped up and replaced with something else. Generally speaking anything sown this spring has gone in superbly and has lifted spirits accordingly.

Better recent weather has led to many outstanding grassweed spraying jobs being completed, with Atlantis or Pacifica (both iodosulfuron + mesosulfuron) being needed in the most difficult situations.

Early first wheats are at GS30 and T0 is now being recommended, an appropriate triazole/chlorothanonil mix proving popular. Disease levels are variable. Very few rust pustules can be found and mildew infections are low, but Septoria tritici levels are high.

Wheat development seems slower this year, possibly 7-10 days late. There is also a huge difference in crop stands where fields are 300-400ft above sea level after the very cold winter. After two weeks of dry weather slug activity is minimal, but rabbits remain a massive problem that still needs addressing.

Pigeons continue to graze oilseed rape heavily causing serious problems. Where the pests have been controlled a minority of strong rape crops have started to extend and grow on quickly.

Most spring barley drilling is complete and seed drilled 10 days ago is shot and should come through during next week.

All winter wheats and barleys have been treated with 37kg/ha of nitrogen plus 45kg/ha of SO3, and second wheats have had the same sulphur and 75-80kg/ha of N. Late September and early October drilled wheats are at GS24.

Oilseed rape crops will soon be at the stem extension stage and have already been treated with 40kg/ha of nitrogen and 75kg/ha of SO3. During the next few days the bulk of the planned remaining N should be applied to backward crops as there is only about 25kg/ha in the soil - only half the amount found last year. Remember the crop can take up to 3kg/ha of N a day during stem extension.

Well established rape crops can wait for their main dressing until the end of March.

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

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

If significant fresh phoma lesions are found on backward crops treatment is still worthwhile. It's still on the cool side for Galera (clopyralid and picloram) to work well, but remember the cut off application point is flower buds visible.

There are some thin and backward barleys around and it's important to remember that barley is less able to compensate for sub-optimal tiller numbers than wheat. So a higher nitrogen dose earlier on to encourage further tillering is worthwhile in these thin crops this year.