At 135mm of rain, May 2014 has been the wettest since I started keeping records in the late 1990’s. Add that to the 57 mm so far in June and I think it’s fair to say that we’ve probably had enough rain now – so hopefully the rest of June and all of July will be dry, hot and sunny.
Yellow rust set off very quickly in the cool wet conditions that we’ve experienced over the last 4 weeks, but well timed and suitably robust T2 sprays have held it in check – albeit only for a couple of weeks in the Oakley – with Kielder, Gallant, Solstice, Santiago, Beluga and Invicta proving almost as filthy in the unsprayed areas of fields.
As I write this, most of my T3 fungicides have already been applied – with the inclusion of an insecticide in many cases thanks to a sudden boom in the grain aphid population – and we were forced into a relatively short 3-week gap between T2 and T3 thanks to the constant rain coinciding with ear emergence and the early stages of flowering.
If we learned anything from 2012, it was that timing is the most critical part of fusarium ear blight (FEB) control, and wet weather at full ear emergence around GS61/62 means you have to get it on sooner rather than later. Whether using prothioconazole (if you were lucky enough to be able to get any), metconazole or tebuconazole – all of whom are equally good on FEB – 75 to 100% dose is a necessity this season, and you will of course top up your foliar control of rusts and septoria at the same time, but it’s worth remembering that even if you get your timing, product choice and dose absolutely spot on, if it is a FEB year, at best you will only ever achieve 50% control – and going with a T4, T5 or even a T6 will do absolutely nothing to control FEB if you missed the timing at T3.
T2 is going on to both spring wheat and spring barley now and, despite the wet weather, rhynchosporium levels in the barley are minimal where prothioconazole-based fungicides have been used at T1. Where blackgrass is an issue in fields, spring barley in the rotation is the clear winner for me as the spring crop choice thanks to Avadex (tri-allate), Liberator (flufenacet + diflufenican) and of course the crop’s own ability to smother blackgrass with its dense canopy.
Chocolate spot has set off in the winter beans in the last 10 days or so, although it should still be in the non-aggressive phase, only turning aggressive in the next 3-4 weeks as temperatures increase. I am also finding increasing populations of both black bean aphid and bruchid beetles in the beans, both of whom will be controlled by the addition of insecticide to the fungicide mix.
In spring beans, downy mildew is now widespread, particularly in Fuego and the catchily named SL567A (metalaxyl-M) on an extension of authorisation for minor use (EAMU) is being applied in mix with azoxystrobin to hold it in check. Potato blight is also a worry in these thundery and humid conditions, with Smith periods running together day after day, so maintaining a strict minimum 7-day interval between applications will be critical for the foreseeable future. Levels of myzus persicae have also increased in the potato crop, so these are being accounted for in the programme too.
Sugar beet varies in size between six true leaves and complete canopy closure – it’s quite early this year – and some issues with leather jackets have been experienced across the county. Broad-leaved weed control in the beet crop has been generally good and time will tell which the Centurion Max (clethodim) will control better – the blackgrass or the sugar beet! On the sandier beet fields thanks to 5in of rain through May, much of the potassium and sodium along with the nitrogen has been washed down through the profile and some crops are struggling as a result – applications of liquid formulations of salt can be very useful to replace leached sodium and potassium in these situations.
If we get plenty of sunshine for the second half of June and all of July, I still think there is the potential for a very good harvest, but – as in many other parts of the country – it won’t be a disease that robs the most off the yield in harvest 2014, it’ll be the bloody blackgrass!