Field beans diseases

Field beans grow well on clay soils and heavy loams, provided they are well-drained and limed (pH above 6). Winter beans are not frost hardy and so are risky to grow, north of the Midlands. In some rotations, beans replace the clover break and they are usually followed by wheat. Yields for spring and winter field beans are shown in Table 5.4. The problem with field beans is their variable yield, which is partly caused by adverse weather conditions and susceptibility to pests and diseases (winter beans get chocolate spot, spring beans are aphid prone), and partly due to the uncertain activity of the necessary insect crosspollinators. 

Field beans are a good break from cereals and are often followed by winter wheat which benefits from the residital nitrogen. To reduce the risk of bitilding up persistent soil-borne diseases such as footrots, field beans and related crops should not be grown within five years of themselves or each other. For spring beans, in addition, stem rot (Sclerotinia sclerotiorum) may be a problem... 

Certified seed is advised but if using home-saved seed it should be tested for germination and seed-borne leaf and pod spot (Ascochyta fabae) infection. Low levels of this disease may be treated with thiram. It is recommended that all field bean seed is tested for stem and bulb nematode (Ditylenchus dipsaci) and should not be used for seed if nematodes are present. PGRO offer a testing service. 

Plant population. Winter beans require an established plant population of 18-20 plants/m post-winter and the chosen seed rate should allow for 20-25% field loss. For spring beans the requited population is about 40 plants/m with a field loss of 0-5%. Dense populations tend to increase disease problems whereas thin crops are less competitive to weeds. In some areas rooks may reduce plant populations. 

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