Spring is well and truly in the air and the long-awaited sunshine and growing day length has been welcomed by growers and agronomists alike. Most of the crops have returned to a more normal green colour than the more familiar yellow colour we have been experiencing.
Early drilled cereal crops are receiving T0s and in most instances growth regulation as well on the forward crops. T0s in general are more robust this year after the mild winter we’ve just experienced due to the higher rust presence which we saw in the winter. November and onwards sown crops have not needed a T0, despite being susceptible to mildew as the disease has not threatened them yet.
Septoria has been around for a number of weeks in more forward crops, but we have been holding off applying a fungicide until leaf 4 had fully emerged. Trying to eradicate septoria on older leaves would not be a cost effective operation. T1s are being planned for the coming weeks based around an SDHI and triazole with chlorothalanil added for essential septoria protection, and also an added mildewicide if mildew threatens or is present in high risk situations. Chlorothalonil cannot be mixed with Atlantis (iodosulfuron+mesosulfuron) so recommendations for grass-weeds were made earlier so there would be no clash now.
Growth regulation choices are being made, namely Terpal (ethephon) based for the barley crops (from GS32) for the prevention of lodging and brackling. Moddus (trinexapac) + CCC (chlormequat) mixes for wheat crops are being or have been applied; the Moddus is added to give a more long lasting growth regulation effect and to strengthen the stem walls.
Pre-T0 applications were discussed a couple of months ago but due to a lack of active yellow or brown rust here in the South, these were never followed though. Most of the barley will not be receiving a T0, as disease to date has not been seen out in the field, but now I’ve written this no doubt it will appear!
Oilseed rape crops are moving towards yellow bud stage, taller varieties such as Fashion and early sown crops which had avoided any slug or pigeon damage have had metconazole-based growth regulation at the start of March for lodging prevention and to improve canopy structure.
We are now looking out for pollen beetles on the buds and monitoring damage and threshold numbers. A green to yellow bud fungicide has been applied to many crops for protection against alternaria and sclerotina; this has been largely MBC and tebuconazole-based as it is a cost effective and has good curative and protectant activity. For late or stressed crops it is best to hold off until it has recovered as applying a triazole may damage the crop.
Spring drilling is continuing well and some of the submerged winter crops have been re-drilled. In particularly black-grassy areas some pre-emergence sprays based on a half rate of flufenacet (Crystal or Liberator) have also been applied under EAMU approvals.
Ground is being sprayed off for maize drilling. Some growers on the south coast will start drilling if conditions allow as soil temperatures are above 8degC. Crops must be drilled into a warm seed bed in order for the crop to get a good start and we want to be sure that frost risk after emergence has passed.
Spring oilseed rape crops have gone in, mainly replacing areas that have had winter crop failure. Spring rape performed well last year and growers are looking for a repeat performance. We will need to be vigilant with flea beetle as these crops have had no protectant seed dressings.