ISSUE 10   July 7, 2005

BLOOMING SOYBEANS

Soybean fields although wet will soon start to bloom throughout the state and in NW Minnesota in the next week or so. Soybean flowering is initiated as the days and the light period starts to get shorter. The beginning bloom stage or R1 stage in soybeans is marked by the plants having at least one flower on any node of the main stem. If there is still a need to spray for weeds, check the label carefully for spraying after flowering begins. There are a number of herbicides that can be used after flowering begins. These include: Assure II, Poast, Select, Arrow, Prism, Basagran, FirstRate, and glyphosate (various formulations). Always read and follow label guidelines when using pesticides.

Soybeans are at 50% bloom when an open flower can be found on every other plant in a row. Flowering, unlike maturity on soybeans, begins toward the bottom of the plant (at the third to sixth node) and then progresses upward and back downward. Branches off of the main stem will flower a few days later than the main stem. While flowering begins at the base of the plant and proceeds to the top of the plant, physiological maturity of the beans will progress anywhere on the plant stem. Normally, soybean pods will be mature in the middle or top of the plant and down, thus remember to check pods toward the bottom of the plant when determining if harvest time has come. Flowering of soybeans is an important time in bean growth and development. At stage R2, full bloom, each plant has accumulated about 25% of its total dry weight and nutrients; it has attained about 50% of its mature height; and, it has produced 50% of its total mature node number. This later flowering stage begins the period of very rapid N-P-K and dry matter accumulation that will continue through R6. Also, during flowering the soybean plant gears up on its nitrogen fixation in order to provide for the demands of the plant. Scout for disease and insect problems (aphids) during this critical early time period of flowering.

Duane Berglund
NDSU Extension Agronomist
duane.berglund@ndsu.edu

 

PULSE TOURS SCHEDULED

The North Dakota Dry Pea & Lentil Association in conjunction with the Williston, Carrington and North Central (Minot) Research Extension Centers will hold the 2005 Pulse Tours. These tours will provide both new and

seasoned producers with the latest information on pulse varieties, production and disease/weed/insect control. The tours are free of charge and open to all interested producers.

  • July 8, 2005-Williston Research Extension Center-8:30 am registration (CST)
  • July 12, 2005-North Central Research Extension Center (Minot)-9:00 am (CST)
  • July 14, 2005-Carrington Research Extension Center-9:00 am (CST)
  • Following the field tours, a complimentary lunch is sponsored by the following platinum sponsors Agricore United, BASF, Philom Bios, Pulse USA and Syngenta. Gold sponsors are Dakota Dry Bean Inc., Fessenden

    Cooperative Association, JM Grain, Meridian Seeds LLC, Nitragin, Premier Pulses International Inc., RailRunner and Superior Grains Inc.

    Source: North Dakota Dry Pea & Lentil Association

     

    CORN GROWING DEGREE DAYS 2005

    The growth and development of corn is largely regulated by temperature accumulations and not calendar days. In fact, corn development can accurately be predicted from corn growing degree day accumulations. Corn growing degree days are calculated using a base temperature of 50 degrees and can readily be obtained from the NDAWN web site (http://ndawn.ndsu.nodak.edu/ ) by going to "corn degree days" under the "applications" section on the left hand section of the home page.

    Although this spring started out much cooler than normal, for most locations in North Dakota corn growing degree days accumulations are ahead of those recorded for the same period in the previous four years (see the following table). At least to date, it appears that we are on track to have a more normal corn season this year.

    Corn growing day accumulations for selected sites in North Dakota for the period May 1 to July 1, 2001-2005.

    Location

    2001

    2002

    2003

    2004

    2005

    Wyndmere

    797

    842

    765

    672

    867

    Fargo

    806

    844

    786

    620

    830

    Williston

    704

    711

    660

    545

    694

    Langdon

    605

    622

    609

    416

    593

    Joel Ransom
    NDSU Extension Agronomist
    Cereal Crops
    joel.ransom@ndsu.edu


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