While we have all enjoyed the long, hot summer of 2018 it has many things to answer for including the failure of a large percentage of potential certified winter bean seed due to poor germination.
Seed shortage likely to fuel bean market
As a result of this shortage of seed it is possible that fewer fields will be sown with beans this season and therefore there is potential for the bean market to rise. There is always a demand for home-produced protein crops. Reduced availability of bean crop could lead to an increase in the price to meet that demand and consequently an opportunity for growers who do manage to plant winter or spring beans.
With less certified seed available growers could consider farm saved seed, either for spring or winter planting. Beans also offer an alternative true break-crop to OSR; a crop which itself has not been without challenges this autumn. Meanwhile, the PGRO has issued derogation on germination levels for beans, down to 70% which makes using home saved seed more feasible – if seed and resulting crop are managed carefully.
Taking a closer look at your beans before saving seed
On a quick visual inspection most bean seeds are smaller than usual and there has been a significant amount of bruchid beetle damage – in many batches far worse than in a 'normal' season.In individual large bean seeds, the effect of the beetle damage may not be significant but when seeds are generally smaller, as is the case this year, losses can be serious.
Beans badly damaged by bruchid beetle should not be used as seed because there is the possibility of the crop's emergence failing due to moulds entering the seed through the damaged skin, once it is in the soil. This can cause the growing point to die.
Crops harvested when beans are very dry, around 12% moisture or less, may have suffered mechanical damage during the harvesting operation. This can be exacerbated during the cleaning process.
If glyphosate has been used as a crop desiccant, seedling abnormalities are likely to arise if seed from the treated crop is used.
Consider professional seed cleaning
The more dry beans are handled prior to sowing, the greater risk of them suffering mechanical damage. Growers farm-saving seed from a harvested crop could reduce this risk by using a professional cleaning service, such as Anglia Grain Services or GFP Agriculture.
As well as safely and efficiently handling and cleaning seed, they will help with germination and quality tests.Tests to determine the germination level of each batch, along with an Aschochyta test and stem nematode test form the PGRO's bean germination testing package.For those not using professional seed cleaning services, a professional agronomist should be able to arrange these tests.
Lower germination requires increased seed rate
Germination levels ranging from 55-85% are more the norm this year.
Once the germination of the seed batch has been tested then a calculation of the required seed-rate is needed, aiming for a field population of 18-25 plants/m2. The 1000-grain weight is needed for this calculation.
Seed rate = (1000 grain weight x no of seeds required per m2) x % expected field emergence
If the germination of the seed batch is considerably lower than normally expected then a corresponding increase in seed-rate is essential. The question might then arise - can I physically sow this required seed rate through my drill at the speed I expect to work? I have already seen a case where these calculations led to a seed-rate of almost 400kg/ha! That the farmer did not believe that he could get through his drill when running at his normal forward speed. A slower drilling forward speed may be advisable in such cases.
Agronomy - previous crop, residues, soil quality and seedbed
It may be that you are sowing a crop of winter beans as a result of the failure of another crop, for example an oilseed rape crop that's been eaten by flea beetle. You must ensure that there are no residues of previously-applied herbicides in the soil that might affect the bean crop's emergence.
Pulse crops are very sensitive to soil compaction and while the hot weather has potentially sorted many soil problems through cracking, there may still be some horizontal 'pans' to be dealt with.
As with all crops the quality of seedbed is paramount. While beans can withstand cloddy seedbeds, to ensure the best results from the chosen combination of soil-applied herbicides a fine, firm and level seedbed is required. The choice of herbicides is very limited so make the most of the period before drilling to utilise a stale seedbed strategy.
Drilling winter beans in mid to late October will ensure first leaves are unfolded prior to the winter. Lighter soils may have more flexibility on drilling-date.
There are many factors to consider when growing beans but, this season more than most, the rewards may be there for those who manage their bean seed and crop well.
If you are considering growing beans, using certified or farm-saved seed, get in touch for guidance on crop management and marketing as well as availability of professional seed cleaning and agronomy advice in your region.