June 22, 2016
Iain Richards Blog: Learning the lessons of 2016
Going into the home straight of the season our wheats are encouragingly clean, our rapes very promising and even our late-sown spring barleys on heavy ground are thick and nicely black-grass free.
But this doesn’t mean we’re sitting back. Instead, we’re looking to learn as much as we can from this season to help us in the next.
Take BYDV, for example. Basing November insecticide timings on Agrii weather station-based predictions of aphid development has kept infections in our wheats to levels unlikely to affect yields. With aphids coming in late in another very mild early winter, though, a lot of crops in our area could have profited from a late December/early January spray or perhaps even an insecticide with their T0s. Even after effective seed treatment protection, we may need to be thinking of two insecticides as standard in future.
We’ve also a lot to learn to keep on top of Septoria. Again, the best decision support information on rain events and latency progression has enabled us to cope with shorter May latency periods than either 2014 or 2015 by flexing our T2 strategies and timings. It’s also meant we’ve kept up pressure on the disease – as well as on both yellow and brown rust in particular varieties – at T3.
However, the major differences in disease development apparent between varieties with Septoria tritici resistance scores of 4-5 and 6 will need much more accounting for in the future – especially where T0 timings risk being compromised by the weather. As will the even greater differences we’ve seen between September and mid-October drilling this season.
The extent to which delaying wheat drilling for black-grass control has helped us manage Septoria provides another excellent reason for patience. Not that many should need any extra incentive with the horrendous black-grass currently being experienced.
This has been especially disappointing as we went into the winter with weed populations of just 5-6 plants/m2 in many cases after very good pre-em activity. Poor competition from crops going backwards in the cold March while the black-grass profited from their nitrogen, however, meant these plants tillered freely to produce 20 or more heads. Unsurprisingly, spring herbicides couldn’t touch them.
Thankfully, late development means we’re unlikely to see much yield reduction from current populations. But we’ll have a truly massive seed return to deal with. So we’ll have to bring every weapon to bear if we’re to avoid huge problems in 2017.
We shouldn’t even be thinking of sowing wheat into bad black-grass fields before the middle of October, for instance. We’ll need to focus on varieties that can be sown later – or in the spring for the greatest flexibility. We’ll need to make our first cultivation the deepest then leave the ground for 6-7 weeks wherever possible and disturb as little soil as possible at drilling. We’ll need to think hard about seedbed nutrition. And we’ll need to prioritise first class weed control in our break crops – especially winter OSR.
We certainly have a lot to think about as we look beyond what, I hope, will be another very satisfying harvest. But learning from experience has always been the best way to ensure we continue enjoying them in the future.