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

Issue # 3, May 8, 2002

• Farm Bill Conference Summary Available on Internet

• Cool, Wet Soils Favor Seed Feeding Insects

• Relative Maturity of Various Crops

• Fertilizing Pastures

Farm Bill Conference Summary Available on Internet

    As of this posting, the how the farm bill will be administered has yet to be completed.  There is a six page summary available on the U.S. House Committee on Agriculture  web site.  The following is a link to this summary.  Farm Bill Conference Summary.

Cool, Wet Soils Favor Seed Feeding Insects

    The cool, wet soils we will likely be planting into will slow seed germination and expose the seed to soil insects for an extended period of time.  There are two insects that have traditionally caused problems in Griggs County.  They are the seedcorn maggot and wireworms.
    Seedcorn maggots: are a yellowish-white worm about 1/4 inch long.  They are a particular problem on corn and dry beans, but may cause injury to potatoes, sunflowers, soybeans and others.  In May, the adult flies emerge.  These flies are small (about 1/2 the size of a housefly) and grayish-brown.  Fields high in organic matter are most attractive to flies.  Fields rotated from corn, small grains or native grass are most susceptible.  
    Eggs of the seedcorn maggot hatch at a 50 degree F soil temperature.  The young maggots feed on decaying organic matter first, but soon begin feeding on seeds, and the inner face of the cotyledons and shoot.  Dry beans are particularly susceptible because the maggot can develop at temperatures below the minimum requirement for dry bean germination (55 degrees F soil temp.).  Factors that delay germination and emergence will favor seedcorn maggot injury.  Picture of Seedcorn Maggot.  The following article describes the susceptibility of the adult flies to a certain fungus.  Fungus-Killed Flies
    Wireworms: also cause more injury when seed germination and emergence are delayed by cool soil temperatures.  These larvae are yellowish, slender, hard-bodied and range in size from 1/4 to 1 1/4 inches long.  Wireworms overwinter as larvae in the soil.  When soil temperatures are warm enough for seeds to germinate, wireworms will already be actively feeding.  Picture of Wireworms.
    Control: There are no insecticide rescue treatments that can be applied to stop injury from these pests after planting.  Treatment decisions must be made prior to planting.  Consult the "North Dakota Field Crop Insect Management Guide" for seed treatment products cleared for particular crops.  

Relative Maturity of Various Field Crops

    As planting is further delayed by cool wet conditions, questions have arisen concerning maturity of various crops.  This is not the first late spring we have encountered in the past five years, but we were given high growing degree days in July and August and also late fall frosts to make up for late planting.  Hopefully this will be the case this growing season.

    Time required for maturity varies with variety or hybrid, seeding date, geographic region and available growing degree days.  A shortage of growing degree days can increase days required for maturity.  Corn, soybean, sunflower and millet are especially sensitive.  (information summarized from an article by NDSU Extension Agronomist, Duane R. Berglund, NDSU Crop and Pest Report, May 10, 1996)

Fertilizing Pastures

    Pasture fertilization has not been a common practice in North Dakota largely due to reasonable cash rents, relatively high cattle prices, and relatively cheap supplemental feeds.  Most of the North Dakota work on pasture fertilization was done during the 1960's through the mid 1980's.  A common theme runs through these studies.  Pasture grass yields response to nitrogen (N) and phosphate (P) fertilization.  Both native and tame grasses are very responsive to nitrogen.  Application of 60 pounds of N per acre nearly doubled tame grass production on low P testing sites in one statewide study, while 60 pounds of N plus P based on soil test increased yields 140%.   Fertilization will increase carrying capacity of treated pastures.
    The best time for fertilization is in the spring prior to stocking pastures.  N fertilizer may be applied as urea, ammonium nitrate or ammonium sulfate.  Phosphate my be applied as 18-46-0, 11-52-0 or 10-50-0.  Urea is the most common product applied.  Application should be 3-5 days before a rain.  Both ammonium nitrate and ammonium sulfate have better waiting periods prior to rain than urea.  Keep animals off following an ammonium nitrate application for a 3-5 days or until pellets disappear due to the possibility of nitrate poisoning.  It is usually not necessary to keep animals off following a urea or ammonium sulfate application.    
    

Please Contact Our Office For Additional Information
E-mail: griggs@ndsuext.nodak.edu
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