Field Bindweed control with a fungus?

Field bindweed is one of those weeds that can seem like a slight problem, something you could just pull up or hoe out and be done – WRONG! Field bindweed is a perennial weed with an extensive root system and a fast-growing top to match. One vine can grow 3-4 feet and it easily grows to the tops of field crops and begins to cover them. Its roots grow equally as fast and if you hoe or chop it out the root pieces just grow a new plant!

The seeds are small but not as small as many others and certainly not as small as pigweed. What makes this weed a real problem in field crops is the fact that plowing spreads the seeds and root pieces so that soon the entire field is covered in field bindweed. Why is it not a problem in pastures or grazed crops? Simply cattle love it! They will continue to eat the weed down and without leaves to make carbohydrates the plant eventually starves to death. The use of grazing is a key to regenerative agriculture, and this is one of the reasons – weed control.

Is there a bioherbicide we can use in organic crop farming? Potentially yes, because over 3 decades ago some researchers found a fungus causing damage to the leaves of field bindweed – Phomopsis convolvulus. This fungus actually carries the title convolvulus as part of its name which is part of the scientific name of field bindweed – Convolvulus arvensis. In this experiment they grew out the fungus and sprayed low to high concentrations of the fungus on various stages of field bindweed growth. Overall, they found that the fungus did kill the leaves but that the extensive root system had enough energy to put out new shoots. Two or more applications are suggested very similar to what is recommended when spraying any chemical control products.

This type of research into bioherbicides is progressing at a fast pace nowadays owing to the lack of chemical herbicides and weed herbicide tolerance. These developments are a big help to the organic grower who can use an organic approved herbicide when nothing else works – and unfortunately field bindweed can easily fit that category.