The recent hot spell of weather has led to a jump in cereal aphids flying into crops. The cooler wet weather will slow them down, but aphids will be building up numbers on crops. Look for aphids on leaves on warm sunny days and consider an aphicide if aphid colonies can be found on 50% of plants. If you are seeing ladybirds or hoverflies in crops then hold off on any aphicides, as these specialist aphid predators will do a good job of mopping up aphids. Check crops again a few days later and if aphids are still on 50% of plants then consider the aphicide option.
As crops move into later growth stages and grass weeds become visible above the crop, it is a crucial time to check that fields are clear of problem grass weeds. Viable seeds can start to be shed as early as June, so it is good advice to quickly remove any plants that are seen. By harvest time up to 90% of black-grass seeds may already have been shed. If a grass weed infestation can be nipped in the bud, it will save a huge amount of hassle and expense in the future. Infestations can be introduced in seed or machinery, and soon become established if they go unnoticed.
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