East: Considering the impact of three crop rule

Crops remain full of promise and with conditions different to those of 2012 dry and sunny weather should hopefully ensure the yield potential of some of these crops is met.

Winter barley crops on the light land have turned very quickly following the recent hot and sunny weather and the most forward crops will not be too far off combining. Oilseed rape has started senescence and desiccation will be due very soon, dependent on weather and crop development.

When considering desiccation timing we should be looking at a representative area of the field and taking around 20 pods from the middle of the main raceme. Having opened all of the pods, if approximately half the seeds are turning brown then the crop should be ready to desiccate in a few days. With some very good wall to wall OSR crops, timing of desiccants should be much easier than last year.

Most wheat crops have received a three or four fungicide spray programme and are generally clean and have very good yield potential, sunlight permitting. It is easy to see differences in variety and fungicide timings. Where spray intervals were stretched between T0 and T1 or T1 and T2 then it is clear to see the high levels of septoria in the base of crops, highlighting the need to get the timings right. Some of the more rust susceptible varieties have received a further fungicide to make five spring fungicides in some cases.

Brown rust appears to be the main concern now, with warmer conditions and disease moving up from lower down the crop canopy. With yield gains being between 0.1–0.25t/ha/day depending on sunlight, water and green leaf area, it is essential to protect this green leaf as long as possible and not let senescence be a result of disease infection. We will also be looking very closely at the yield of different varieties vs the level of fungicide spend on disease control before committing to varieties for next season.

Where contracts permit, late foliar nitrogen will be applied to milling wheat crops as they approach the early milky ripe stage. Checking previous year’s yield, applied nitrogen and grain protein results will provide a guide as to the required quantity of foliar N. However, with good yield potential the risk of protein dilution and low grain protein has resulted in higher rates nitrogen being applied.

Cropping plans for next year are starting to take shape as we find out more about the CAP changes. Without neonicotinoid seed treatments the area of OSR needs to be limited to a manageable area that can be sprayed quickly if cabbage stem flea beetle becomes a problem. The lack of a cold winter may result in higher numbers of larvae pupating and more adults present this autumn, so consider where OSR fields are this autumn in relation to last year’s OSR. Another concern is the number of slugs being found in the current wheat crops, with over 50/sq m found in a quick count one morning in a wheat crop and this will also impact on the ability to establish the following OSR.

With the three crop rule, many wheat and OSR rotations will be changed to include spring cropping to get on top of grassweed problems, with spring barley providing the best herbicide options and the most crop competition. Pulses may also be introduced where conditions allow and farms require additional Ecological Focus Areas (EFA), there are also a few new niche break crops being suggested, which will make things interesting. Although the changes are frustrating in some cases, it will result in better crop rotations, improved crop management, better grassweed control and also allow us to improve soil structure and fertility.

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