Crop watch: avoid delay to T2 timing – Farmers Weekly – Ben Pledger

Ben Pledger looks at agronomic issues in the East ...

The recent welcome rains have started flushing weeds in winter wheat, with cotyledon stage seedlings now appearing out of cracks produced by the dry weather.

With not a lot of chemical weed control included in the winter wheat T1 fungicide spray, tank mixing of herbicides at T2 will be more prevalent this season where crop canopies allow penetration to the weed.

Although T1 fungicides may have only recently been applied, the temptation to delay the T2 timing to allow the boots to split and get some active ingredient on to the emerging ear should be avoided. The flag leaf and leaf 2 contribute to more than 60% of yield, and to leave these unprotected is a big gamble.

Septoria is present on some lower leaves, and the wetter, warmer weather will have accelerated its progress up the plant towards the upper, unprotected canopy.

Fluxapyroxad or benzovindiflupyr will form the base of the T2 fungicide mix, and will be tailored to individual varieties depending on their ratings for septoria and rusts.

Where stock exists on farm, chlorothalonil will be added to the mix to protect against septoria, keeping in mind the 20 May cut-off for this active ingredient.

Herbicide cut-off

Growth stage cut-off timings for herbicides should also be observed when adding them to the mix. Prothioconazole will feature on milling varieties to start fusarium control.

Sugar beet crops are at differing stages in the region, mainly driven by seed-bed moisture at drilling.

In places, where land had to be worked late on to produce a fine seed-bed suitable for beet, valuable moisture was lost and seed ended up sitting in dry seed-beds until the recent rains. This has left some fields with growth stages varying from cotyledon to six true leaves.

Weed emergence has been as protracted, and with hot daytime temperatures last week, and now cold nights as well as thresholds for aphids having now been met in a large number of fields, sequencing an insecticide in with herbicide timings and intervals has been tricky, to say the least.

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