Article Archives
30 Years Ago

Thursday, March 30, 2023
filed under: Historical

        Trap Cropping / By Gary Brewer, NDSU Entomologist — “For many folks, mention of the term ‘trap cropping’ may evoke images of 19th century Rocky Mountain fur traders harvesting beaver pelts.  In modern-day agriculture, however, trap cropping is something quite different: a type of intercropping purposely designed to increase yield by reducing pest damage.
        “Trap cropping as an insect management practice is not a new idea, having been used for a number of years in crops such as corn, cotton and soybeans.  Nor is it an entirely new concept in sunflower.  A small number of oil-type sunflower producers have used trap cropping to control red sunflower seed weevils — and, in the process, have become astute observers of the relationship between the crop and this particular insect. . . .
        “To be effective, a trap crop must be more attractive than the main crop for at least a portion of the critical insect-invasion period.  With sunflower and the red seed weevil specifically, that means diverting the weevils into the trap crop and away from the main crop.  While seed weevils will go to sunflower in any stage of growth, they strongly prefer plants which are in the blooming stage.  So the objective is to attract the weevils to trap rows of early blooming sunflower, thereby allowing the grower to control the weevils before they infest the remainder of the field.
        “In 1990, a cooperative trap-cropping project was initiated between Kulm, N.D., sunflower grower Daryl Rott and this article’s author.  A LISA (Low Input Sustainable Agriculture) grant helped fund the study, which was expanded in 1991 and 1992 to additional farms in Rott’s southeastern North Dakota vicinity. All of the on-farm trials were conducted by the farmers themselves in oil-type sunflower field sizes ranging from 52 to 132 acres. . . .
        “Not every planted trap crop in the 1990-92 trials worked as anticipated.  Some of the farmers encountered problems in executing the trap-crop design.  Among the obstacles were (1) partially overlapping bloom periods between trap and non-trap rows, and (2) weather conditions preventing the insecticide treatment of trap rows at the proper time.  Despite these difficulties, however, the trip design did result in red sunflower seed weevil populations which were low to the point where spraying the entire field would have, in most cases, been unprofitable. . . .
        “[T]he trap design usually should prevent a field-wide economic infestation of red sunflower seed weevils.  By using a trap field to manage weevils in oil-type sunflower, a farmer can expect to prevent an economic infestation at approximately 10 percent the cost off conventional insecticide treatment.”
        TV Root Scoop / By Don Lilleboe — “Federal government employee Steve Merrill is a close observer of underground movements. 
        “So that means he’s an intelligence agent who has infiltrated political extremist groups?  No, not at all.  Merrill, a USDA soil scientist stationed at Mandan, N.D., studies the root development of crops — including, as of 1992, that of sunflower.
        “Merrill uses a miniature video camera to visually observe root development throughout the growing season.  The camera is inserted into a clear plastic tube about four inches in diameter.  This tube, inserted into a predrilled hole early in the season, lies at a 30-degree angle (for viewing convenience) and extends down to approximately a six-foot depth.
        “Root magnification is essential, Merrill notes, since the most important roots, in terms of cumulative length, as well as water and nutrient uptake, are the finest (i.e., smallest) ones.  With sunflower specifically, these tiny roots at the end of the branching system may be just 1/100th of an inch or less in diameter . . . .
        “The miniature TV camera is connected to a controller and video monitor above ground, where the operator views and measures the plant roots. . . .
        “Through his underground observations, Merrill is able to view the growth of sunflower roots under the various continuous cropping systems at the [Mandan USDA farm]: no-till, minimum-till and conventional tillage; as well as the growth of ’flowers planted on ground which has been summer fallowed.  He describes his observations as ‘a means for us to better understand how important aspects of soil management — in particular, conservation tillage — affect the soil and crop yields.’
        “Many variables impact a crop’s root growth development, Merrill emphasizes: soil type and moisture profile; fertilization, growing season climate (rainfall , temperature); interaction with (and competition from) weed species; and, of course, tillage.  ‘It’s a very complex system,’ he notes.  ‘To understand what’s going on — and to devise practical farm management systems — we have to understand the basic plant-soil relationships.’ ”
        One-Pass Roto-Tilling/Incorporating/Planting / By Don Lilleboe — “Randy Edson will be planting just his third sunflower crop in 1993; but he couldn’t be more please with how well the crop has performed within his rotation the first two seasons.
        “A big part of the sunflower success equation on Edson’s southwestern Nebraska farm has been its easy fit into the one-pass tillage/planting system he has used with corn for nearly two decades.  Edson . . . uses two John Deere 7100 MaxEmerge six-row planters mounted on rotary tillers to work the seedbed and plant in a single pass.  He applies and incorporates his herbicide at the same time.
        “One of his two tillers was produced by Kelly Manufacturing, while the other is an FMC ‘Sidewinder’ unit. . . . ‘They’re basically just big garden tillers that fit behind a tractor.’ Edson explains.  A standard usage is for ridge-tilled corn, much of which is grown under flood irrigation in the area. . . .
        “Edson plants his corn and sunflower crops in 36-inch rows.  The tillers work an 18-inch band, tossing some soil into the inter-row untilled area.  While he bands his corn herbicide, Edson goes with the broadcast rate of Treflan for his ’flowers.  ‘The rotor-tiller throws enough dirt to cover up that herbicide even where we’re not tilling,’ he says, noting the typically good soil moisture and ‘almost automatic’ herbicide activation.  ‘So we’re incorporating between the rows as well as in that 18-inch tilled zone.’ ”
          Sonalan 10G Receives Federal Label — “Sonalan 10G granular herbicide recently received a federal registration for control of grasses and broadleaf weeds in sunflower, soybeans, other oilseeds and dry edible beans.  Granular herbicides are growing in popularity among farmers who are leaving more crop residue on the soil surface, says Mike Donnelly, product manager for Sonalan’s manufacturer, DowElanco. . . .  Sonalan 10G is labeled for control of 22 grass weeds (such as foxtail and wild oats) and 20 broadleaf weeds (such as lambsquarter, pigweed and kochia.”
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