Many fields that were growing beans this spring are now planted to winter wheat. A number of bean crops did not grow very tall and consequently set their pods very low to the ground. This resulted in many pods being left in the field and consequently the seed fell on the floor, chitted and has now become a weed within the wheat crop, a volunteer bean.
The easiest way to kill these volunteers is with a hormone herbicide however that is a spring time job. The autumn applied black grass herbicide should take care of the majority, provided it is the correct one.
Why are volunteers a problem?
Often all the seed from one or more pods grows in the same small location. This means that the wheat plants are killed off via direct competition. Secondly if left unchecked the beans achieve a size that can directly interfere with the accurate and even application of contact herbicides applied in the spring for grass weed control.
How well have the autumn herbicides worked?
There is always a corner where the sprayer boom does not quite reach and here we see the effect of no herbicide on beans and blackgrass alike. Symptoms and effects from residual cereal herbicides then take a little while to show so a degree of patience is required. After about a month, bean growth slows, ceases and then the plants start to die back. The end result, smaller and fewer volunteers in spring 2021.