The following is from an article by Tom Peters, Extension Sugarbeet Agronomist with NDSU & U of MN, published in North Dakota State University CROP & PEST REPORT July 10, 2014 Issue, with a Manitoba perspective by Pam de Rocquigny, Manitoba Agriculture Provincial Cereal Crops Specialist
If you take a drive across Manitoba, you’ll notice the impact of excessive moisture on crops. Symptoms of excess moisture can include crop yellowing, hastened crop development such as premature bolting in canola, stunted growth, and in extreme cases crop death in drowned out areas.
What options do producers have to manage these drowned out spots? Producers should continue to actively manage these areas of fields since they are a perfect environment for weeds to grow without crop competition and potentially will produce tremendous numbers of weed seeds. Left unattended, these spots could dramatically impact weed management strategies for future crops in future years.
So what options does a producer have? Some questions to consider are whether you can reach these spots with equipment such as a rotary mower or a sprayer and what will effectively control the weeds?
- Mowing is a good option, but in all likelihood, affected areas in fields will need to be mowed on 10 to 14 day intervals to prevent weed seed production.
- Spray the drowned-out areas of the fields as if you were managing a crop if you are still spraying the field for weeds (if the drowned out spots have dried enough for a sprayer pass of course). If you are spraying only the affected areas, be sure to consider the crop around the drowned out spots to prevent damage to the surviving crop. And keep in mind any potential crop rotation restrictions to next year’s cropping plans with the product you are using.
- A third possibility is to plant the drowned-out areas of the field to a cover crop such as a cereal, once again if the area is dry enough to allow a seeder to pass. Cover crops will use excess water in soils and will compete with weeds for light and thus may limit germination and emergence of weeds.