Field beans pests

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. 

Stem eelworm (Ditylenchus dipsaci) is an important seed-bome pest of field beans. Home-saved seed should always be tested for it and the status of certified seed should be ascertained as well. 

Mainly a pest of spring beans. It also attacks sugar beet and mangels. Populations of aphids and amount of colonisation and predation by beneficial insects vary each year. Warning systems are available. The threshold for treatment is 5% of plants infected in headland on windward side of field pre-floweiing to 2.5% infected across field and colonies spreading onto pods. 

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