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ISSUE 4  MAY 27, 1999

CANOLA STANDS

    Some canola is emerging while some fields have been reported to have erratic stands. The question
comes up, what is an adequate stand in canola? Seeding rates of 5 to 6 pounds per acre should result
in 700,000 seeds dropped per acre depending on seed size and numbers per pound. An ideal stand of
canola seedlings should be 500,000 plants per acre or 11 to 12 plants per square foot. We don’t always
reach this ideal goal. What is the "minimum" stand of canola population required to still obtain decent
potential yield? Research results from Canada and U.S. have shown that 4 plants per square foot is the
minimum stand to still expect good yields. Weed competition however becomes minimal with reduced
stands. The canola plant has a way of compensating with additional branching and a thicker stem to
support the extra branching when growing under a reduced or lower plant population.

    An easy method to determine the stand count in canola is using the "hula hoop" method. Use a hula hoop
in a drilled or solid seeded canola field. Randomly toss the hula hoop in 10 different areas of the field
and make counts within the hoop.

    Using the table below, multiply your average counts by the multiplication factor which corresponds to
the size of the hoop being used. The product answer equals the plant population per acre. This method
will also work with solid seeded soybeans in row’s 8 inches or less in row spacing.

Hoop Diameter

Multiplication Factor

30 inches

8,900

32 inches

7,800

34 inches

6,900

36 inches

6,200

38 inches

5,500

    Example: 36 canola plants in 32 inch diameter hoop equals: 36 x 7800 = 280, 800 plants/A or 6.5 plants
per square foot. Canola plants per "hoop count" to equal the minimum 4 plants per square foot.

Hoop Diameter

4/ft.2 minimum (canola)
(Number of plants)

30 inches

19.6

32 inches

22.3

34 inches

25.2

36 inches

28.1

38 inches

31.7

    After you have counted and determined the canola stand, you can investigate further to see if any
additional canola seedlings will or can emerge. Dig or scratch below the soil crust and see if any old
or new seedlings have a chance to emerge. Once all the information is assembled then one can judge
to leave a field or replant to another crop. Reseeding to canola is getting late and rather risky for this
1999 season.

Duane R. Berglund
Extension Agronomist
dberglun@ndsuext.nodak.edu

 

ALFALFA HARVEST IS UPON US!

    On May 24 we checked the research plots at NDSU for stage of maturity. The most mature stem
in alfalfa that was not winter injured was just beginning to bud. The tallest stem was 26 inches. If we
use the Prediction Equations for Alfalfa Quality (PEAQ) system developed by Ken Albreck at the
University of Wisconsin, the RFV of the standing hay is estimated at 187. If prime hay (RFV=>151) is
the target, alfalfa harvest should begin before the alfalfa’s RFV drops below 175 since about 25 to 35
units of RFV are lost in the harvesting operation.

    The recommended maturity stage to begin harvesting changes with the height of the alfalfa. The taller
the stem is, the earlier harvest must start in order to harvest prime hay. For example, an alfalfa that is
20 inches tall can be harvested at late flower for the most mature stem and still make prime hay; whereas,
a 30-inch-tall alfalfa must be harvested by late vegetative in order to make prime hay. As a guide,
harvest should begin at late vegetative if the tallest stem is 30 inches, early bud if 28 inches, late bud
if 25 inches, early flower if 23 inches, and late flower if 20 inches when shooting for prime hay. Late
vegetative is defined as the tallest stem of at least 16 inches tall with no visible buds or flowers, early
bud is 1 to 2 nodes have visible buds with no open flowers, late bud is more than 2 nodes have visible
buds with no open flowers, early flower is 1 node with at least one open flower, and late flower is 2 or
more nodes have open flowers.

    Alfalfa scissor cut results on May 25 in Becker County Minnesota indicated the RFV to range
from 176 to 245 across 9 sites and averaged 210 according to Harouna Maiga, the county agent.

    The weather forecast is for several dry days with temperatures nearing 80oF. It appears now is the
time for alfalfa harvest to begin in southeast North Dakota. The northern half of North Dakota appears
about a week later due to less height at this time. Southwestern North Dakota should also be close to
harvest since temperatures have been warmer than in eastern North Dakota.

Dwain Meyer, Professor
dwmeyer@prairie.nodak.edu

 


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