for Weeds: Planting to Rosette
Conduct a survey after planting but before cultivation to determine the spectrum of weeds present. Weed control after planting is most critical during the seedling stage. Once established (4–5 inches tall), most cole crops can shade out weeds.
Depending on when you monitor, you may see winter annual seedlings, summer annual seedlings, or perennial weeds. Weed surveys can help you select herbicides, rotational crops, and cultural practices.
How to survey your field
- Walk through each field in a random pattern.
- Rate the degree of infestation for each weed species on your weed survey form. Use either a numeric scale from 1 to 5 (1 being the lightest, 5 being the heaviest), or rate as light," "medium," or "heavy."
- Check fencerows, ditch banks, field edges, and wet spots as these may be problem areas for weed growth and potential sources for wind disseminated seed. Note the dominant species on the monitoring form.
- Pay particular attention to problem weeds.
- Sketch a map of the field and mark areas with major weed infestations for follow-up control action, noting carefully the location of weeds producing seed.
- Indicate the growth stage of the weed (seedling or mature).
- Record results on a weed survey form.
Survey information collected over a period of years tells you how weed populations may change and how effective your management operations have been over the long term. By knowing which species are present, you will be able to make appropriate decisions on cultural and chemical controls.