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AgAlerts 2003 From Griggs County
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Issue # 3, May 30, 2003
Each year I receive questions concerning
pocket gopher control in yards and gardens. Pocket gophers are found only
in the western hemisphere. Their range is from Panama in the south to
Alberta in the north. There are six species found in the Great Plains and
are variable in their distribution. The two species found in North Dakota
are the "plains pocket gopher" and the "northern pocket
gopher". Only one species of pocket gopher usually is found in each
locality.
Typically there is only one pocket gopher per burrow system.
Exceptions are when mating occurs and when the female is caring for her young.
The burrow system consist of a main burrow, generally 4 to 18 inches below the
ground surface, with a variable number of lateral burrows off the main.
Maximum depth of at least some portion of a burrow may be as great as 5 or 6
feet. The diameter of a burrow is about 3 inches, but varies with body
size. A single burrow system may contain up to 200 yards of tunnels.
The rate of mound building is highly variable. Estimates include an
average of one to three mounds per day and up to 70 mounds per month. This
activity brings a large amount of soil to the surface, estimated at 2.25 tons
per gopher each year. For a population of 50 southern pocket gophers, it
is estimated that they can move 47 tons of soil in a year. The tunnel
system is rigorously defended against intruders and constitutes the home range
of the pocket gopher, which may be up to 700 square yards. This why this
little animal is a vary busy and a major nuisance in crops, gardens and yards.
Control: The most common ways of control is by trapping or by
poisoning. The key to the efficient and effective use of these methods is
locating the burrow system. The main burrow generally is found 12 to 18
inches away from the plug on the fan-shaped mounds. When the main is
located, place the poison bait in each direction of the tunnel. Then block
off the opening with soil or sod. Pocket gophers are attracted to an
opening in their system and may cover the bait with soil as it plugs the
opening. If large acreage is need to be treated it can be accomplished
with a "burrow builder machine". This method works well in areas
of minimal rocks.
Trapping is extremely effective to control pocket gophers in
small areas and to remove remaining animals after poisoning control program.
For more information, link to "Pocket
Gophers and Their Controls" or "Using
Burrow Builders for Pocket Gopher Control".
Tan spot has been observed in wheat fields in
the eastern and central parts of the state. Typical symptoms are 1/8"
to 1/4" diameter tan spots on the leaves surrounded by a yellow halo.
Under favorable weather conditions, these spots will spread and join
together. Under cool weather conditions, the spots may have a purplish
halo.
Net blotch has been observed on a few barley fields around
the county. Net blotch is a fungus that overwinters on barley stubble and
can be spread by wind and rain. Early symptoms on the leaf are minute,
light green or brown spots that soon enlarge into longitudinal brown
streaks. Within these lesions, darker longitudinal and horizontal lines
may develop, giving the blotches their characteristic netted appearance.
Control: For early season control can be obtained by
applying Tilt or mancozeb fungicides. Application can be done by applying
the fungicide by itself or tank mixed with a herbicide. Half of the
labeled fungicide rate can give good control at this early stage of
growth. Most herbicide tank mixes are NOT prohibited with these two
fungicides. However, tank mixing of Achieve and Cheyenne herbicides with
either fungicide is prohibited by the herbicide label and Stampede is prohibited
from being tank mixed with Tilt. Monitor the crop at flag leaf emergence
to determine if another application may be beneficial.
The conditions for stand establishment has been good in most areas. There has been a few reports of crusting problems with soybeans. The following table address minimum stands acceptable several crops.
| Minimum stand levels of several crops that should be considered acceptable before replanting | ||
| Crop | % of Normal Stand | Minimum Stand |
| Small Grains | 30 - 40 | 8 - 14 plants/ sq. ft. |
| Flax | 20 - 40 | 20 - 35 plants/ sq. ft. |
| Soybean | 25 - 50 | 37,500 - 75,000 plants/acre |
| Navy Bean | 50 - 60 | 45,000 - 60,000 plants/acre |
| Pinto Bean | 40 - 50 | 28,000 - 35,000 plants/acre |
| Corn (Dryland) | 60 -70 | 16,000 - 20,000 plants/acre |
| Estimation of plant population on a per acre basis for row crops. | |
| Row Width | Row Length (1/1000 acre) |
| 20" | 26'2" |
| 22" | 23'9" |
| 28" | 18'8" |
| 30" | 17'5" |
| 36" | 14'6" |
| Count the number of plant in row length and multiple x's 1000 to determine number of plants per acre. Example: 24 plants counted in 17'5" row length of 30 inch spacing = 24,000 plants/A. | |
| Soybean seeds per lineal ft. of row (Seed Count of 3000 seeds/lb.) | ||||
| Seeds per foot of row width row spacing in inches of: | ||||
| Seeds/Acre | 6" | 12" | 22" | 30" |
| 120,000 | 1.4 | 2.8 | 5.0 | 6.9 |
| 150,000 | 1.7 | 3.5 | 6.3 | 8.7 |
| 180,000 | 2.1 | 4.2 | 7.5 | 10.4 |
| 201,000 | 2.5 | 4.9 | 8.8 | 12.1 |
Please Contact Our Office For Additional Information
E-mail: john.swenson@ndsu.edu
Go to the 2003 AgAlert Index Page