East: Pollen beetle still below threshold

When I look back at what I was writing about last year we were contending with snow and slow backward crops, what a difference a year makes and a bit of dry weather.

OSR crops are generally at the green bud stage with pollen beetle numbers still below threshold, therefore an insecticides cannot be justified. Some crops are showing signs of light leaf spot, therefore a prothioconazole + tebuconazole fungicide will be applied to provide light leaf spot protection, early sclerotinia protection and some plant growth regulation.

BASF/ADAS sclerotinia monitoring sites were indicting low levels of sclerotia germination as of the March 19 due to the dry conditions, but any rainfall is likely to increase the sclerotia germination with soil temperature already suitable for germination.

OSR crops are due to receive their final nitrogen dose before they are too tall to travel through. The weather has helped delay nitrogen uptake and due to the large canopies and high green area index (GAI) total nitrogen dose in some cases has been reduced by around 20-30% to prevent excessive vegetative growth. Where this is the case foliar nitrogen may be applied after petal fall to feed pod development.

In wheat, where rust was evident, a triazole +/- morpholine fungicide was applied during late tillering with the focus now turning to protecting the new growth. The recent dry weather and cooler nights has slowed crop and disease development with T0 fungicides being applied this week, ensuring no more than a three week interval to the T1.

With the variations in growth stages the main focus now is monitoring leaf emergence by peeling back the leaf layers and identifying when final leaf 3 is likely to emerge in order to time the T1 correctly. On the most forward wheat, final leaf three will be emerging around now, which is earlier than normal. Depending on the interval from T0 this will require a fungicide to protect this yield contributing leaf from disease once it is at least 50% emerged or within 3 weeks of the T0 being applied.

Picture: Leaf layers on a forward crop of winter wheat taken on the March 20. Final leaf 4 emerged and final leaf 3 about to emerge, much earlier than normal.

Leaf layers

Winter barley has received a T0 fungicide especially where rust or mildew was developing, allowing us to tidy up existing disease and also apply an early PGR and trace elements on well tillered crops.

With little frost tilth this year spring seed-beds have been difficult to work, however, where we have been patient crops have gone into warm and moist seed-beds and spring barley has germinated within seven days. Sugar beet seed-beds have been a little more difficult, with rain required prior to drilling in order to achieve a fine enough seed-bed to cover the seed.

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