It’s a typical British spring, with temperatures two weeks ago above 20C. This week barely into double figures in the day, down to zero and below most nights. We have at last had a little rain in most areas and with many crops already showing moisture stress, it arrived just in time. The showers will help uptake of fertilisers which, until now, have been sitting on dry soil. Many growers are planning to apply nitrogen fertilisers earlier than usual, to allow for what may be another dry summer, with slower crop uptake.
T0 fungicides have been applied to most winter wheat and T1’s to winter barley. Forward wheat will be due a T1 treatment within the next 7-10 days. Yellow rust and, occasionally, brown rust could be found in susceptible varieties prior to T0 and will need careful choice of an appropriate fungicide at T1. This will probably include a suitable strobilurin. Note that SDHI fungicides alone are not ideal for yellow rust and require additional triazole to improve control.
There are high levels of eyespot in second wheats; choice of product is again very important. Septoria tritici, as usual, is the number one target at T1. Some varieties have high infestations on the lower leaves, Invicta probably being the worst.
Weevils are attacking both winter and spring beans. Leaf damage is very severe but the real harm is caused by the weevil larvae feeding on the root nodules of the beans. Normally, only spring beans require treatment but where leaf attack is particularly severe in winter beans, it is probably worth spraying, especially if the crop is under stress. Chocolate spot can also be found in winter beans and usually requires a two-spray treatment, three weeks apart.
In winter rape check for pollen beetles in crops where flowering has yet to start. There have been high numbers in some crops. Once the majority of plants is in flower, spraying is unnecessary.
Most rape crops have had a fungicide at green/yellow bud and are now at the early flowering stage. Main nitrogen doses have been applied with some held back for application during flowering.