Weed in field
Hi and thanks for contacting Ask an Expert.
That plant is called 'stinking chamomile' locally. I use a stirrup hoe to cut it off. It is easy to pull when the ground is wet also. Of course getting it out in early spring is the best. This is an annual but also determined to be invasive meaning it will spread all over the yard. Here is a link to give you a bit more information. https://www.invasiveplantatlas.org/subject.html?sub=5106
This plant is called 'stinking' because of its bad odor but more importantly it can cause blisters. Use gloves if you touch it. It needs to be removed ASAP. Even though it is an annual, it disperses thousands of seeds and will re-appear in larger numbers next year. When you remove it, bag it and put in the garbage.
A vinegar or acetic based herbicide can be used. Or you can make it yourself. Use regular white vinegar, the kind you buy in the grocery store – 5 to 7% strength. Put it in a gallon sprayer with a couple of tablespoons of regular vegetable oil and 2 tablespoons of Dawn liquid soap, no water. Dawn has degreasers in it that will break down the leaf structure of the weed. The oil is used as a sticker to help the vinegar stay on the plant. Shake often to mix the ingredients. Protect yourself from the fumes of the vinegar, even though we use it in our food, it can burn tissue if inhaled. Do not spray on any plants you do not want to die. Do this on a calm day. Do not water the plants. It works best when it is hot and it may need to be re-applied as this plant has a tap root and the vinegar does not kill the root, at least the first time. You might want to fence off the chickens for a day when you do this but it should not harm them and quickly leaves the soil.
You can plant within days and it is recommended so the weed seeds do not have a chance to germinate. If you have any further questions, please re-contact us.