The first of the oilseed rape crops are now starting to flower. This means that the pollen beetles are now a beneficial rather than a pest. Once flowers open, they will come to those flowers first to harvest pollen rather than burrowing into the unopened flower buds. While collecting pollen, they are also pollinating the crop. There are likely to be bees around the crop as well, so don’t spray for pollen beetle once the crop is flowering.
Attention is now turning to the sclerotinia threats. The forecasting service is suggesting that the potential threat is high this year, but night temperatures are well below 7 degrees (we had another frost last night, the 4th in week) and there is no/little rain forecast. This means that the threat is still relatively low at the moment, even though sclerotinia germination started in March.
However there are also the physiological benefits to consider before delaying the application too long. With the current price of OSR, you don’t need much of a yield increase to pay for the cost of spraying even in the absence of disease. I’m recommending Galileo (picoxystobin) at this first timing and saving the Filan (Boscalid) for the second sclerotina spray.
While the OSR crops are motoring on, the cereals, particularly wheat, seem to be slowing up their growth at the moment. Most barley is at GS31, (I did hear a report of a crop in Dorset having flag leaves out last week) and have had their T1 fungicide and PGR. Some are looking as though they are getting drought stressed now, but generally crops are looking good and the yield potential is there.
Wheat crops are between GS30 and GS31. Most of the T0’s are now on and have cleared up the disease that was around, particularly the rusts. There is still some mildew lurking in some crops but, generally, levels are low. That may change as dew levels are very high at the moment.
Septoria is mostly on the older leaves and has yet to jump upto the fresh growth, but that will change as soon as we get some rain events. The frosts we are getting will be holding back rusts and mildew but likely to have less of an effect on the septoria. T1 sprays are looking as though they will be earlier than normal, but not as early as we first thought.