Good progress has been made with spring cereal drilling, even on heavier land away from the Downs. Moist seed-beds are surprisingly good on the whole, allowing many well-timed applications of a pre-emergence herbicide.
Cereal crops are steadily moving towards GS30, with T0 fungicide applications containing a robust rate of products containing actives tebuconazole, chlorothalonil, prochloraz and a mildewicide where appropriate, but with the main aim of cleaning out stem-based diseases.
Some early drilled winter crops have been sprayed, but for most crops the optimum timing is about now (4 April). The slightly warmer and wetter conditions will have maintained disease risk and so despite a desire to cut costs, fungicide is not the input to put at risk if yield is to be protected. Septoria and mildew are still evident in many wheat varieties, with net blotch and mildew typical in most barley crops.
I have noted some direct drilled cereals, while not always as advanced as crops in cultivated fields, do seem to be showing less disease and are very well rooted, this may bare more details with analysis. Generally all winter cereals have now received their first nitrogen application of between 30-40kg of N. They now have enough healthy growth to begin tissue testing to help assess nutrient levels.
Aphids are still easy to find in cereals, there is a concern about barley yellow dwarf virus (BYDV) infection. BYDV is showing up in barley where weather conditions last autumn/early winter conspired against spray applications and mild temperatures meant aphids continued to migrate and reproduce in crops later than would normally be expected.
Oilseed rape crops that I have looked at don’t have such serious flea beetle damage as reported further north. Larger, earlier drilled crops seem to have coped better with the larvae, which appear to have been able to feed in the leaf petioles without needing to bore into the stems.
With good crops (there are some!) moving quickly towards yellow bud/early flower, this will initiate the start of monitoring for sclerotinia. Current risk is low, but will increase as soils warm. Light leaf spot is still active and will be the priority for fungicide application – if not already addressed. A prothioconazole-based fungicide at flowering for sclerotinia, such as Propulse (fluopyram + prothioconazole) will add to light leaf spot control. It has to be said that there is a massive variation in oilseed rape growth stages across the region.
Later crops in the green bud stage may be at risk from pollen beetle damage, with surprisingly large numbers been found this week. Oilseed rape is a very resilient crop and research has shown that it produces more buds/flowers than it needs to achieve potential yield and these excess buds can be sacrificed to pollen beetle before yield is affected.
Where treatment is justified and if pyrethroid resistance is suspected, alternative insecticide options will be considered, for example Plenum, Rumo or Biscaya. Resistance to pyrethroids in the pollen beetle population is continuing to spread as shown by DuPont’s monitoring in 2015.
Weather permitting, your sprayers will soon be very busy.