The 60mm of rain we had in October seems relatively little compared to comments from fellow Cropwatch agronomists, who reported 150mm over the same time period elsewhere. Crops generally look very well and even the bare patches on heavier soils that were slow to emerge due to the dry have now greened up.
Oilseed rape crops look well and the dry August and September has prevented many from becoming thick forests which are knee high. Overall phoma levels are still low, but it is clear to see the different levels of disease based on their susceptibility to the disease. Fungicides are being applied whilst conditions are still good for travelling. With light leaf spot being an important disease in this area, fungicides are being used which have activity against this, as well as phoma. No autumn fungicide often means chasing light leaf spot in the spring, which often becomes a case of damage limitation by then.
Applications of contact acting herbicides such as Atlantis (iodosulfuron + mesosulfuron) and Broadway Star (florasulam + pyroxsulam) to winter wheat crops have, and are, being applied to control grass weeds such as blackgrass and brome. However, with crops emerging patchily on heavier parts of the field it has been difficult to decide whether to use these herbicides now or wait until the spring. This is because grass weeds such as blackgrass are only just beginning to emerge on the heavier soils, with more to come, yet on the lighter parts of the field they can be at the 2-3 leaf stage. Decisions can only be made on the basis of where most of the blackgrass has emerged or not, but it all adds to the challenge in trying to achieve good control.
Keep checking for slugs on later sown wheats, particularly following oilseed rape, as they are causing some damage. With crops not growing as fast now compared to earlier sown crops, they will remain vulnerable for a longer period. Plants need to be at the three-leaf stage before they are strong enough to withstand grazing.
A lot of winter beans have now been drilled and thankfully most have been drilled into good seed-beds. These good seed-beds should help to maximise the performance of the pre-emergence herbicides that are being applied. With so few post-em herbicide options available the pre-ems are central to the overall weed control programme.
