Winter wheat crops are now moving rapidly after receiving early doses of nitrogen and most are now at, or near, GS30 leading into April. Even late-drilled crops are relatively forward due to the mild winter. Similarly, winter barley crops are growing quickly and reaching GS30/31.
Early Plant Growth Regulators are also now being applied to the most forward cereal crops. Classic dead heart symptoms, caused by wheat bulb fly, are appearing in wheat. Little can be done other than early nitrogen and rolling fields to help the crop past the damage.
Although oilseed rape crops are variable this spring due to establishment and/or cabbage stem flea beetle damage, most are now at green bud and the most advanced at early flowering. Some crops have been written off due to poor establishment or the fact that they are carrying far too many cabbage stem flea beetle larvae to make a viable crop.
With the exception of a few second early varieties, very few potatoes are in the ground so far. Planting of maincrops is likely to start in earnest in April.
Thoughts are now turning to imminent applications of T0 fungicides, which will begin in the first week of April. These are likely to be based around chlorothalonil to protect final leaf 4 and 5, with the possible addition of either a rust-active strobilurin or tebuconazole where yellow rust is present on lower leaves. So far, although there is plenty of Septoria and, in some varieties yellow rust, there is little sign of other diseases.
Now is a good time to start checking wheat crops for initial signs of eyespot. If the disease is found, plan for a T1 fungicide containing 150g/ha of prothioconazole. Little can be done to cure eyespot after T1 and a majority of current wheat varieties on the Recommended List have low resistance to this disease. An application of 1L/ha Aviator (bixafen + prothioconazole) or 1.2L/ha of Ascra (bixafen + fluopyram + prothioconazole) both have adequate prothioconazole to give good eyespot activity.
Any fungicides for plant growth regulation and light leaf spot control should have been applied by now and thoughts now turn to flowering sprays to protect crops from sclerotinia. Again, Proline (prothioconazole) or other prothioconazole-containing products are a good choice, whilst also helping to reduce the risk of light leaf spot reaching the upper canopy.
Pollen beetle have made an appearance in some oilseed rape crops. At present, I have not seen many crops at threshold and as flowering begins, the threat from this pest recedes. Monitor crops that have not started to flower and spray ONLY if thresholds are met. Deltamethrin (for example, Decis) may give some level of control and Biscaya (thiacloprid) is useful non-pyrethroid option if required. Avoid spraying any insecticides onto crops whilst pollinating insects are active.
Sugar beet planting is in full swing and the crop seems to be going into good seed-beds with warming soil. A small area of beet was drilled during the good weather in late February and early March. It has been very slow to emerge, and it is yet to be seen if these crops have lost their vigour and will establish poorly.
The next few weeks should be spent monitoring for crop and weed emergence and getting ready to apply herbicides when the first flush of weeds reaches cotyledon stage. Betanal MaxxPro (desmedipham + ethofumesate + lenacil + phenmedipham) at 1L/ha plus Goltix (metamitron) at 0.75-1L/ha would be a good start to the herbicide programme, whilst being generally quite gentle on the crop.
With the approval of Velum Prime (fluopyram), growers have a new and alternative approach to potato cyst nematode control in potato crops. This new liquid nematicide applied in furrow at planting, at the rate of 0.625L/ha, and has created a lot of interest from growers and their customers alike.
Bayer has also just received approval for a new potato herbicide in the form of Emerger (aclonifen), which will be a useful tool in the weed control armoury now linuron has been withdrawn. It is unlikely to be available until later in the season, but there should be an opportunity for growers to use Emerger as a pre-emergence tank mix partner on later-planted crops.