AgAlerts 2002 From Griggs County
By John Swenson, Griggs County Extension Agent


Issue # 9, June 25, 2002


HRSW Leaf Rust

    Leaf rust has been found in the western part of Griggs County and eastern Foster County.  The fields I looked at are showing very low levels at this time.  But if we continue with hot humid conditions, these levels could increase.  So at this time monitor the NDSU Small Grains Disease Forecasting Model to see how many days are favorable for rust development.  For more information on wheat rust can be found in NDSU Extension publication "PP589, Wheat Rust". 

Common Milkweed Control 

    (This article was written by Clint Gienger, Traill County Extension Agent)

    Common milkweed has become a severe weed in cultivated cropland due to an extensive, deep root system, insulating winter snow, moist to wet summer conditions, tolerance to many commonly used herbicides, reduced tillage, and lack of human persistence in chemical, mechanical, and cultural control measures. Common milkweed is tolerant to most labeled herbicides. Control requires multiple herbicide application. Preventing establishment and spread of common milkweed patches requires continuous scouting and persistent control efforts.
   
Prevent seed production. Milkweed seed is highly viable and will germinate readily. Pappus on seeds allows long-distance travel and is responsible for establishment in fields. Common milkweed becomes perennial (capable of reproducing from underground roots) approximately 3 weeks after emergence. New shoots developing from established roots begin emerging in late April and grow more rapidly than spring seeded crops.
   
I checked with Rich Zollinger, NDSU Extension Weed Specialist on his recommendations for multi-year control strategies. He indicated that his research and other states research shows that during the small grain year the combination of a ounce of Express plus ¾ pint 2,4-D and 2 ounces of Banvel gives the best control. In addition, a pre-harvest treatment of Roundup at 1 quart per acre will enhance the control of this persistent weed. If soybean follow wheat in your rotation, Roundup Ready varieties should be considered because most other soybean herbicides have very little or no activity on milkweed.
   
For individual plants or small patches, you may want to try a wick application of Roundup. Either hand or mechanical wick applicators can be used but be cautioned not to get the herbicide on growing crops. This method will only work if the milkweed is taller than the growing crop. For wick applicators you should mix a Roundup and b water in the applicator.
    The following link explains some of the "Uses of Milkweed"

Maple Bladder Galls

    Bladder galls are caused by mites.  The brilliant red color often associated with the bladder galls makes them spectacular and conspicuous.  Consequently, they cause much concern among tree owners.  They are unaware that the colorful growths on the foliage are rarely detrimental to the health of the tree.  Maple gall mites overwinter as adults under bark scales, where they are able to withstand severe weather conditions.  Early in the spring they move to unfolding leaves and begin feeding.  Mites that cause bladder galls fee on the undersides of the leaves.  Initially, a slight depression results.  The leaf then rapidly produces a pouchlike gall at that spot, enclosing the mite.  The mite continues to feed and lays numerous eggs within the gall.  Reproduction is prolific, and as mites mature, they leave the gall and continue infesting new foliage.  By July, mite activity on the foliage ceases.  Sufficient foliage unaffected by galls is produced during a growing season to sustain the tree without serious harm.

maple bladder galls on silver maple    leaf distortion caused by maple blader galls    maple bladder galls turning red in color   

Common Chickweed

    This is a common lawn weed that has an interesting history.  David Van Der Puy, former NDSU Extension Agronomist compiled a short history about this weed.  The following is a summary of his research.
    Chickweed derives its common name from the fact that the plant was widely fed to poultry in England.  The plant has been eaten as a pot herb by man for centuries.  It was one of the few green plants available during the winter months.  The Puritans are thought to have introduced chickweed to North America and are said to have cultivated it in gardens.  Chickweed is now found throughout many areas of the United States and Canada.  It appears to be best adapted to the east and central states.  However, it has been found growing wild well into the Artic Circle.  The medicinal qualities of chickweed have been touted since early Greek and Roman days.  Chickweed was used as late as the Middle Ages as a curative ointment for hemorrhoids, sores, sundry and other skin ailments.
    There are four of five different kinds of chickweed in the United States with common chickweed being the most wide spread.  Common chickweed is considered to be a major weed problem in lawns, nursery stock and  a number of specialty crops.  The plant can be either an annual or a winter annual which germinates in the fall and completes its life cycle the following spring.  Chickweed can germinate and grow at very low temperatures and can even grow slowly in early spring or winter under snow.  The plant often passes unnoticed during the early part of the life cycle in the late fall or early spring until warmer temperatures cause it to flower.  By this time, the effectiveness of control measures are significantly reduced.  Also, chickweed prefers shaded areas near trees or shrubs witch prohibits the use of certain herbicides for its control.
Control measures:  The following link to Purdue University Turfgrass department will list controls and pictures of lawn weeds.  Click on common chickweed in the index section for description and controls.  Midwestern Turfgrass Weed Identification and Control.


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E-mail: griggs@ndsuext.nodak.edu
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