It appears to be monsoon season here in Lincolnshire, with 59.2 mm of rain so far this month – the majority of that falling over the last 10 days. Still at least it’s been too windy to spray when it hasn’t been raining!
The yellow rust epidemic didn’t happen then thank goodness, and inevitably growth stages are moving on a pace though, winter wheat flag leaves are now widely emerged and T2 fungicides are being applied. I have to say I don’t think I’ve ever seen cereals looking this clean heading towards ear emergence – spotless down to leaf 5 in the main where T1 Aviator at 1.0 litre/ha was employed as a replacement to my old favourite Tracker at 1.5 litres/ha .
There was a school of thought in the industry back at T1, that with wheat prices where they were, with low levels of disease and low disease pressure that money could be saved on the T1 fungicide by going down the triazoles plus chlorothalonil route. But as I’ve said before, Septoria really doesn’t care whether wheat’s £100/t or £200/t, or whether your crop is thick or thin – if you’ve invested money in drilling the crop you need to look after it with the best tools you have available to you.
If you did cut back on your T1 you really need to make sure you put something very robust on at T2 and clearly that means new generation SDHI at – or very close to – full rate. The reason you need to be robust is that if you have merely suppressed Septoria in the canopy down to leaf 3, as soon as conditions become favourable, that Septoria will cycle rapidly and infect the canopy without mercy.
With this in mind, now that conditions are perfect for the proliferation and spread of septoria and indeed rusts, a minimum dose of 80% triazole plus new generation of SDHI +/- chlorothalonil and +/- strobilurin would appear to be the only sensible course of action. There is no question that you will get your money back from new generation SDHI chemistry at T2, and choose your weapon wisely – cost it out because value is something very different to cost.
The benefit of a couple of kgs of MgSO4 should not be underestimated at this timing either – it costs pence and as demand for Mg is high at this time of year, the last thing you want is the ear stripping it out of the flag leaf.
Staying with winter wheat and the blackgrass is beginning to rear its ugly head despite us doing everything cultural and chemical to prevent it. The worst uncontrolled areas in all crops will be glyphosated off to prevent further seed return and, once again we will be rogueing where levels are still low to keep them that way.
Orange wheat blossom midge timing is also nearly upon us, and if moist soil conditions, soil temperatures in excess of 13C and warm, still evenings coincide with pupation and midge flight in the early stages of ear emergence, it could possibly be an issue for the first time in 10 years. So monitoring is critical and despite what some people may say to you, widespread or routine applications of chlorpyrifos should not be undertaken.
Like the yellow rust in winter wheat, the rhynchosporium epidemic never happened in the winter barley either, it’s spotless from top to bottom. The ear began to emerge around 14 days ago in the more forward pieces and so final T2 fungicides have already been applied on all of my winter barley – yield potential is good even if the price isn’t.
Oilseed rape is all, but finished with now with final protectant sclerotinia sprays going on last week – seed weevil levels hit threshold for the first time in a few years so they were dealt with at the same time. And like cereals, disease levels are generally low – although we did have to spray in mid March to combat the sudden increase in light leaf spot – and they are podding well so, hopefully, good yields will follow.
Sugar beet has been all over the place really, ranging from cotyledon to eight true leaves – and with the recent windy and wet weather, opportunities to spray at 100 litres/ha of water through a fine nozzle have been few and far between! It really is worth sitting down with a calculator when it comes to sugar beet herbicides, because so many reputable manufacturers have products similar to each others in the marketplace.
There are several for example which contain phenmedipham, desmedipham and ethofumesate in various different ratios – all good quality, well formulated products – but just compare what you’re getting for your money and you might be surprised!
Centurion Max has now been applied on sugar beet fields which are full of spring germinating blackgrass, but only once we felt we were in control of the broad-leaved weeds – because having to leave 14 days before and after any other treatments means a month without broad-leaved weed materials being applied. The sugar beet has not enjoyed the recent cold soils and cold temperatures, looking stressed – albeit wheat free – in many fields, and the recent hailstorms we’ve experienced in these parts haven’t helped their demeanour!
Spring beans and peas are now beginning to show buds and first flowers, so all broad-leaved weed spraying has ceased – the timing of first fungicides plus insecticides for Bruchid beetle will coincide with the setting of the first pods should conditions dictate. Syngenta have a very useful Bruchid beetle forecasting tool on their website.
Potatoes are emerging well, outstanding control from pre-emergence herbicides mean weeds are few and far between, and blight spray programmes will be starting as soon as the rosette stage is reached – you can’t be too careful when it comes to blight!