West: Severe septoria infection shows in some crops

 

With it all over bar the shouting, it now just remains to be seen whether we have got things right this year or not. There is a lot of talk about 2015 being a low disease year, even in this part of the world. The evidence coming to light now in some fields would tell a lie to this theory.

There are several brown fields of wheat (severe septoria infection) now beginning to show themselves. There is definitely a common thread to these crops and it is a two-fold story of poor or missed timings and/or crops not treated with SDHI chemistry. Severe septoria this early in the grain fill period is going to have a massive negative effect on yield and quality and will make the saving on SDHI chemistry seem pretty paltry.

So why has this happened? It is quite simple really. In March we were realistically facing the prospect of uncontrollable septoria. Early drillings, combined with a mild wet winter meant that we had the highest levels of septoria in crops as we approached T1 that many could ever remember. We struggled with the disease in 2014, but early septoria was far worse this year.

However, we were extremely fortunate to have three weeks of completely dry weather in April, which let us of the hook a little and broke the very rapid cycling of septoria in the crops. What this dry weather did not do was eliminate the high levels of inoculum waiting in the bottom of the crops for the rain to return. As soon as the rain returned, the disease took off again in crops that were either not protected due to poor timings or were protected, but by inadequate chemistry. The lesson is a simple one. In the Southwest you ignore or under-estimate septoria at your peril.

On a more positive note, most crops are looking very promising. The wheats have had very little rain through the flowering period, so should come under little pressure from fusarium. Winter barleys are generally looking very well and are now beginning to ripen quite quickly.

The oilseed rape crop looks promising, but we have been here before and been disappointed. Combining the crop is the only way of determining whether the promise of a good yield actually materialises.

There are some outstanding looking spring barley crops about this year. Some will not want to see any inclement weather if they are to remain upright.

Maize crops have finally started to grow and look healthy. Cold nights and a persistent northwesterly wind have certainly tested the crop over the last month.

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