New calculator estimates economic yield loss from SCN

New calculator estimates financial yield loss from SCN


Editor’s word: The next was written by Greg Tylka, Iowa State College professor within the Division of Plant Pathology and Microbiology, for the Built-in Crop Administration Information web site Nov. 10.

The outcomes display of the SCN Revenue Checker reveal an estimated 19.1% yield loss, which represents $173.81 per acre loss based mostly on a 70 bu./acre yield expectation and $13 per bushel advertising and marketing worth.

The soybean cyst nematode is believed to value soybean producers $1.5 billion yearly in North America. A brand new on-line useful resource from the SCN Coalition makes use of information collected from Iowa State College analysis to estimate the price of yield reductions from SCN in particular person fields.

The calculator, named the SCN Revenue Checker, is obtainable at and permits customers to supply particular details about particular person SCN-infested fields to gauge the potential financial value of yield loss brought on by the nematode. The device relies on information from greater than 35,000 ISU SCN-resistant soybean selection trial analysis plots in 180 research performed from 2001-20 all through all 9 crop-reporting districts in Iowa.

The calculator can be utilized for fields identified to be infested with SCN and which have been sampled for SCN. Additionally, the calculator is supposed for use with fields the place soybean varieties with PI 88788 SCN resistance have been grown.

The consumer gives the next in regards to the SCN-infested subject:

  • the SCN egg inhabitants density (eggs per 100 cc of soil),
  • the feminine index of the SCN inhabitants within the subject on PI 88788 resistance (a %),
  • the % sand content material of the soil within the subject, and
  • the pH of the soil within the subject.

The calculator asks just for the data above as a result of these had been the one elements that considerably affected yield within the information that function the premise of the calculator. If multiple SCN soil pattern was collected from a subject to find out SCN egg inhabitants densities, the typical of the pattern outcomes needs to be entered into the calculator.

Individuals are additionally studying…

The calculator estimates relative yield discount expressed as a proportion. P.c yield loss is transformed into estimated financial yield loss based mostly on the farmer’s yield expectation for the sector and advertising and marketing sale worth aim.

Though the calculator is constructed from analysis leads to Iowa, the % yield loss can be utilized for a variety of geographies. And customers needs to be conscious that the results of climate, facets of the precise soybean varieties grown elsewhere, native soil circumstances, and different elements additionally might have important results on yield loss brought on by SCN in a person subject. For this reason the output from the calculator needs to be thought-about solely an estimate of potential yield loss.

There are a couple of conditions through which the calculator shouldn’t be used, specifically if the SCN egg inhabitants density is 0 and if the soybean selection grown this season was inclined or possessed Peking SCN resistance. Additionally, getting into excessive values within the calculator, corresponding to 80,000 eggs per 100 cc of soil, 100% sand, or pH of 10.0, probably will produce unreasonable yield loss estimates.

How is the feminine index decided?

The feminine index of an SCN inhabitants on PI 88788 is set by an HG sort check. The index signifies how effectively an SCN inhabitants is managed by the PI 88788 supply of resistance that’s generally used to breed soybean varieties.

When soybean varieties with SCN resistance from PI 88788 initially are used, the SCN populations are managed effectively and feminine indices usually might be between 0 and 10%, indicating 90 to 100% management. In conditions the place soybean varieties with PI 88788 SCN resistance have been grown repeatedly for quite a few years (corresponding to in Iowa), SCN populations evolve to develop excessive replica on PI 88788 resistance and feminine indices are 50% or better, indicating that PI 88788 resistance gives decreased management of the nematode. The decreased effectiveness of resistance results in better SCN replica, elevated egg inhabitants densities, and better yield loss.

As soon as a consumer selects the state through which the sector of curiosity is positioned, the calculator robotically gives a default feminine index for PI 88788 that was offered by a college SCN knowledgeable in that state. This permits farmers who have no idea the feminine indices of the SCN populations of their particular fields to make use of the useful resource.

For Iowa, the default feminine index is 45, which is the midpoint of the vary of feminine indices at present identified for SCN populations within the state. The estimated yield lack of a subject decided by the calculator might be most correct if precise feminine index values are identified and used.

The calculator was created by the SCN Coalition as an instance to farmers and people who advise them the financial profit from actively managing SCN. “Energetic” SCN administration entails soil-sampling fields repeatedly to observe SCN numbers, rising soybean varieties with differing SCN resistance genes, rising soybeans in rotation with non-host crops corresponding to corn, and experimenting with nematode-protectant seed therapies when soybean are grown to see which offer a yield enhance.


Supply hyperlink