While August is historically a wet month, this year has proved to be particularly frustrating for many.
With July’s early heat wave promoting comparisons to last year’s dry harvest, the start of combining began well with winter barley and oilseed rape started at least in good conditions.
However, hot on its heels was a very unsettled period of wet, windy and cool weather more akin to autumn conditions than summer.
While this time last year you felt like you could lose a limb down one of the mammoth cracks that opened up in the stubbles, this year reports of grain trailers and combines getting stuck has been the norm.
In Northamptonshire I recorded in excess of 150mm rainfall from mid-July to mid-August and watching the news it is clear that we were not the wettest county.
While the amount of rain has proved problematic it has also been the nature of the rain that has caused increased frustration with short heavy showers scuppering plans to combine on otherwise dry and windy days.
However, as the August bank holiday approaches sunshine looks to be on the cards and hopefully a more settled period of warm dry weather will see growers finally manage to get some much-needed combining done.
While the wet weather has caused much frustration with regards to harvest, seedbed preparation and the drilling of rape has got off to a good start.
With many planning to drill early this year with the aim of having an established crop by the main flea beetle migration, growers have made a good start with many crops drilled at the start of August being now at one true leaf.
Flea beetle activity has been minor so far with the wet weather keeping the beetle at bay.
However, with the main period of migration normally occurring around the August bank holiday weekend and with weather set to be fair for this period we may experience an onslaught of attack by the time this article is printed!
It is hoped though that with the better growing conditions being experienced this year the crop will have a better chance to grow away from the adult feeding pressure.
Pyrethroid insecticides are the only alternative to neonicotinoid seed treatments for the chemical control of flea beetle adults and larvae.
However, with CSFB resistance to pyrethroids being found this approach can result in poor control. It is important therefore that pyrethroids are used in a rational manner to minimise the development and further spread of resistance.
Treatment thresholds currently advise that a spray is only required if 25% of leaf area is lost at the 1-2 leaf stage – with this increasing to 50% of the leaf area lost at the 3-4 leaf stage.
Cultural methods of control should also be employed including where possible rolling twice, sowing into firm, fine and moist seedbeds.
While much attention is given to flea beetle it is important not to forget the damage slugs can have on rape crops.
High volumes of straw, moist seedbeds and minimal cultivation all increase the potential for slug activity in the new crop.
The use of ferric phosphate to control the pest is still advocated due to its better environmental profile over metaldehyde products; however, following the recent High Court ruling on metaldehyde the previous expiry dates have been reinstated for all products and metaldehyde products can be purchased and used as before.
Although metaldehyde is once again available for use it is still of great importance when using metaldehyde products that the best practice guidelines are followed to ensure its continued availability going forward.
To ensure the rape crop has the best start it is also important to consider the crops autumn nutritional needs.
Rape has a higher nutritional demand in the autumn when compared to cereals, so where soil indices are low seedbed fertiliser should be considered.
Up to 30kg N/ha can also be applied to the seedbed or as a top dressing and can be beneficial to the crop particularly if straw has been incorporated causing the lock up of nitrogen.
Finally, a last word on the harvest of field beans. Field bean harvest timing is often pushed as seed bed cultivations and oilseed rape drilling together with early pesticide applications take precedence.
However, while beans are often perceived to be able to withstand harvest delays their quality does start to deteriorate if left too long with pods splitting and beans being exposed to light, darkening the seed coat and increasing crop loss when harvested.
If quality is to be achieved for human consumption premium do not delay the harvest of beans unduly.
Beans are often stored on farm for long periods of time, if destined for human consumption they should be stored in the dark to delay the development of tannins which can result in the beans being discoloured. Beans should be dried down to 14% moisture content if they are to be stored long term in bulk.