Ten days of dry weather have allowed for application of pre and early post-emergence herbicides to cereals and for maize harvesting and subsequent drilling to go ahead.
Beans are now being planted and must be sprayed with pre-emergence herbicides, there being very little available for post-emergence broad-leaved weed control. Grass weeds can be dealt with post-emergence if necessary, using contact graminicides but a pre-emergence treatment is an essential starting point for what should be looked at as a “cleaning crop”.
Blackgrass is emerging strongly in cereals and the pre-emergence herbicides are beginnning to take affect. Some crops are showing the affects of earlier pre-emergence sprays, probably because they were not drilled sufficiently deeply or perhaps had heavy rain following spraying.
A follow-up treatment of Atlantis (mesosulfuron + iodosulfuron) will be needed in wheat and if the dry weather continues there will be an opportunity for spraying it in the autumn. Timing will be critical as we have to decide whether or not all of the blackgrass has emerged.
Aphids can be found in cereal crops and will need spraying to prevent barley yellow dwarf virus. With the majority of crops now receiving pre-emergence herbicides, there is a temptation to ignore the BYDV threat rather than go through crops with an insecticide only, but that must be a potentially dangerous strategy. Deter seed dressing will protect crops through the early crop stages but if the weather stays mild a follow-up insecticide will be necessary, especially in high risk areas.
Phoma is at low levels in oilseed rape so at present no fungicides are being applied. Many crops, especially on thinner soils, are developing very slowly and still have only four leaves, despite nitrogen application in September. Soil temperatures are still too high for Kerb (propyzamide) application and it will probably have to wait until November.