NDSU Extension - Williams County


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August 19, 2015

White Butterflies


I have been receiving a lot of phone calls the last two weeks about these white butterflies that are flying around everywhere. Whether you live in a rural setting or in town, you have noticed an increase of butterflies. You see them a lot of times in ditches, canola, alfalfa and flowered areas, many are wondering if they are a pest and how to kill them. These butterflies belong to the insect family Pieridae and to the group called Sulphurs and whites, which are either white or light yellow in color. The reason why we are seeing these butterflies now is because they emerge in late summer in large numbers. They feed on pollen and nectar of flowering plants, they generally do not cause harm to the flowers or crops. There are 14 species of this group found throughout North Dakota, common examples are the cabbage butterfly and alfalfa butterfly. The cabbage butterfly is the most common, they are attracted to plants in the mustard family (cabbage, broccoli, cauliflower and canola) and can be found in gardens/flower beds.  The larvae’s appearance is green, with usually one or more pale lateral stripes with a velvety appearance. The larvae do cause some damage to cabbage, broccoli and cauliflower by chewing holes and the leaves and bore into the heads of those vegetables. The butterfly is white in color, the females have two black spots on the forewings (front wings) and the males only have one on the forewings. There is no need to kill these butterflies, enjoy them while they last. This information was gathered from NDSU Crop and Pest Report, Number 15.


Planting Winter Wheat


With harvest in full swing, some of you might be thinking about planting winter wheat. Right now is the time to start preparing, with winter kill and diseases being some of the challenges, here are some ways to lessen the chance of losing your crop.

  • When possible plant winter wheat into standing stubble. Planting into canola and flax fields is highly recommended because of the tall, erect stubble, but any stubble that will retain snow will work. Planting winter wheat into wheat stubble is not recommended, as the chances of diseases significantly increases.

  • Plant winter-hardy adapted varieties, the following have been developed in Canada and North Dakota; Accipiter, Decade, Jerry, Moats, Peregrine, Radiant, WB Matlock. Additional information to help you chose a variety can be found in the winter wheat variety selection guide. https://www.ag.ndsu.edu/pubs/plantsci/smgrains/a1196_14/pdf

  • Planting in September is the optimum times, in the northern half of North Dakota it is recommended September 1-15. Although in recent years the first ten days of October have been largely successful. The last practical date of planting for winter wheat will depend on the weather, since there still must be enough moisture and growing degree days so the seed can germinate.

  • Plant 1 to 1.5 inches deep, adequate moisture for establishing winter wheat is a concern, since the soil profile is usually depleted of moisture in the fall. Planting shallow (1 to 1.5 inches) and waiting for rainfall is recommended, planting shallow also allows for faster emergence with the temperatures rapidly declining.

  • Seed about one million seeds per acre, the higher seeding rate, up to 1.2 million viable seed per acre, may be appropriate is planting late or into a poor seedbed. Excessively high seeding rates may result in more lodging by harvest time.

  • Breaking the green bridge is critical to reduce the risk of infection of the Wheat Streak Mosaic virus. This disease is vectored by a tiny mite that moves green tissue to green tissue. After harvest, and killing of volunteer weeds/crops, allowing two weeks will allow time for the mite to go through its lifecycle. This means that the mite will not be found on a subsequent host (volunteer weeds) to feed on and transmit the virus.

  • Avoid varieties that are highly susceptible to scab, even though scab is not a normal concern when planting winter wheat. Choosing varieties that are the most tolerant, especially if planting in a field where scab has been an issue that past year. The varieties that are recommended for scab tolerance are; Emerson, Lyman, Art, WB Matlock and Jerry.

This information was gathered from the NDSU Crop and Pest Report, number 15.


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