East: Rain brings increased phoma risk

The last two seasons have provided us with the two extremes in weather; surely next season can’t be any worse and somewhere in the middle would be just right for next season. Yield and quality has been very variable and compared to last year – 70% more rain and 30% less sunshine during April, May and June is where the initially high yield potential was lost.

Volunteer cereal control has begun in oilseed rape before they become too competitive. Where blackgrass is at the 1-3 leaf stage, tepraloxydim or cycloxydim will be used for early blackgrass control unless resistance is an issue, in which case carbetamide may be used earlier. This should prevent blackgrass getting too well established and deeply rooted prior to propyzamide being applied later in the season.

The recent wet weather will encourage phoma development and with later drilled crops and small plants emerging, crops should be inspected regularly. Small crops and susceptible varieties should be prioritised and fungicide applied as soon as 10% of plants show phoma symptoms.

Unfortunately, the much anticipated ethametsulfuron has failed to gain registration therefore there will be no easy options for controlling charlock and other troublesome broad-leaved weeds this autumn.

Winter wheat drilling began at the end of last week, somewhat later than normal due to a lack of moisture with particular attention paid to the thousand grain weight (TGW). TGW ranged from 31g to 48g and where we may be aiming for 300 seeds/m2, the drilling rate can vary from 93kg/ha to 144kg/ha. It is therefore crucial that seed rates are adjusted based on TGW, seedbed conditions and drilling date to avoid overly thick crops next spring.

The dry conditions have resulted in some knobbly seed-beds and now we have moisture, slugs are likely to be a continual problem. Therefore pressing, rolling and double rolling may be beneficial to ensure fine and firm seedbeds. We must also ensure we keep within the 210g/ha metaldehyde stewardship limit.

Pre-emergence sprays have been in the shed for some time now, with flufenacet forming the backbone. With greater reliance on pre-emergence control and stacking of actives, care should be taken to ensure seed is well covered and heavy rain is not due post application.

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