Sample Dry Beans for Cyst Nematode

We recommend that dry edible bean growers soil sample their fields for soybean cyst nematode (SCN). This is particularly important in Southeastern and East Central
North Dakota, where SCN is most commonly found in the state.
Like soybeans, dry edible beans are susceptible to SCN. Also like soybeans, above-ground symptoms of infected dry edible beans are not diagnostic for SCN.
Infected dry edible beans may only appear stunted, yellowed and have poor canopy closure (Figure 1). SCN can be observed on the roots, but as plants age it is
increasingly difficult to identify (Figure 2). Consequently, soil sampling is the best way to test for the nematode.
Methods to sample dry edible bean fields for SCN are the same as soybeans. Sampling can be done anytime now until freeze-up. Using a soil probe (or shovel), take 10-20 subsamples per field, 6-8 inches deep, aiming for the roots. Mix the sample and submit to a lab. If you do not know if you have SCN, sample area where SCN is most
likely to be first introduced such as field entrances (on equipment with soil), periodically flooded areas (with flood water) or near shelter belts (dispersed with blowing soil).
Sampling high pH soils is also a good area to sample, as high pH favors SCN reproduction. If you already know you have SCN, understanding your egg levels will help you make management decisions next year.
Research conducted at NDSU demonstrated that different market classes of dry beans have different susceptibility to SCN. SCN was able to feed and reproduce on kidneys beans just as successfully as a susceptible soybean. SCN was able to feed and reproduce on pinto and navy beans, but at a reduced rate when compared to susceptible soybeans.
Among all the market classes tested, feeding and reproduction was lowest on black beans. It is notable however, that differences among varieties within the market classes exist. If we were to use a soybean scale to compare the market classes, results would suggest that Kidneys would be rated ‘S’, pintos and navys ‘S/MS/MR”, and blacks ‘MR’.
For more information on SCN biology, SCN distribution in ND, and SCN sampling, please see my articles from last week.
(Source: Sam Markell, plant pathologist, NDSU Extension)

Soil Health Field Days Happening Wednesday

NDSU Extension is holding Soil Health Field Days on Wednesday, August 25 at various locations. The entire event will be held live at Mooreton and broadcast at NDSU Research Extension Centers (RECs) in Streeter, Carrington and Langdon. Field tours at the RECs will also be held after. 
Registration for all locations and online is available at:

Soil Sampling Tips

Due to the large amount of residual nitrate left after the short crops in the state, there will be more soil sampling than usual. Here are a few tips to increase the practical use of the results from sampling.
  1. The soil may be hard where there has not been recent rain. It will be important for the sampler to make certain that the core is the correct depth and not to give up if the going gets tough. If a core comes out of the sampling tube incomplete, discard it and redo the sample a few feet over.
  2. Don’t work the land before the sampler arrives. The ability to take a 0-6 inch core required for P, K, organic matter, zinc, and surface nitrates (necessary for sugar beet recommendations) is much degraded if the soil is worked, particularly after chisel plowing or (God forbid) deep chiseling or plowing.
  3. When sampling, do not take samples from the headlands, or the turn rows around sloughs, because these areas have legacy overlap inherent with fertilizer/manure application. Make a mental note not to sample within 100 feet roughly of the edge of the field or around obstacles that would have resulted in applicator turning. The exception to this is in zone sampled fields with salty areas next to roads/sloughs. These should be sampled as a zone, because the NPK fertility in these areas will probably be vastly different than the rest of the field and fertilizer savings can be achieved by identifying these areas.
  4. To build zones, use multi-year yield mapping data, aerial imagery of growing crops, satellite imagery from growing crops, soil EC or EM sensor data if available, and topography if it can be identified and properly modeled (raw elevation data should not be used as it usually does not indicate a landscape position). The Web soil survey should not be used as a first zone development tool. It was not designed for this purpose and the boundaries are usually misleading.
  5. Know that nitrate sampling, or sampling for K for that matter, are moving targets and there is a plus-minus value at the end of analysis. Persistent dry weather after sampling will result in a spring value that is similar in nitrate to what is found now. Wetter weather may result in a bloom of nitrate, but this late in the season the increase in nitrate will be small, if seen at all. Nitrate may be immediately tied up in residue breakdown, with the awakened microorganisms that have been dormant all season. K values are at their lowest now through early September and if it stays dry, the K values will be low through fall. However, freeze-thaw and any moisture during winter/early spring will increase values, so next April the highest K values of the year are seen. It is best to analyze for K at about the same time during the year each time K is analyzed (it doesn’t have to be every year) to make sure that the relative values of K can be tracked and not be confusing.
(Source: Dave Franzen, NDSU Extension)

NDSU Crop and Pest Report

The 16th issue of the NDSU Extension Crop & Pest Report for 2021 has been released. Topics featured in this week’s edition are:
  • Entomology
  • Plant Science
  • Plant Pathology
  • Weeds
  • Diagnostic Lab
  • Around the State
  • Weather Summary/Outlook

NDSU Crop and Pest Report

The 15th issue of the NDSU Extension Crop & Pest Report for 2021 has been released. Topics featured in this week’s edition are:
  • Entomology
  • Plant Science
  • Plant Pathology
  • Weeds
  • Diagnostic Lab
  • Around the State
  • Weather Summary/Outlook

Dry Bean Scene

During the field day held at the NDSU Langdon Research Extension Center (LREC), research agronomist Bryan Hanson highlighted row spacing and population trials being conducted at the LREC. Hear more in the latest Dry Bean Scene. This radio update is made possible, in part, by the Northarvest Bean Growers Association.

Dry Bean Rust Could Appear Soon

Currently, NDSU Extension is not getting calls about dry bean rust, but anticipate that it may appear soon. Scouting for dry bean rust is important even in a dry year. The disease definitely won’t occur everywhere, but if it is identified it can be managed with fungicides. Dry edible bean rust can occur in dry years and is favored by moderate to warm temperatures.
Like other rusts, the pathogen needs free moisture (leaf wetness, dew, fog, etc.) to infect; not necessarily rain. Dry bean rust infection is also influenced by microclimates. Open and/or thin canopies make the microclimate less favorable for dew and less favorable for rust, while a lush dense canopy makes heavy dew and rust infection more likely.
Read more on page 11 of the Crop and Pest Report.

Scout for Spider Mites in Dry Beans

The first reports of spider mites being found on field edges of soybeans came in this week from West Fargo, ND and Crookston, MN, according to the NDSU Extension Crop & Pest Report. Spider mites are small (1/50 of an inch long) and magnification is usually required to see them. A 10x hand lens is helpful in seeing spider mites
in the field.
Spider mite infestations typically are first noted near field edges, so start scouting at field edges to see if spider mites are present. A quick sampling procedure to determine whether mites are present is to hold a piece of white paper below leaves, then beat the leaves to dislodge the mites.
Spider mites appear as tiny dust specks and they move slowly after being knocked off the leaf. Another method is to pull plants and examine the undersides of the leaves for
mites and webbing.
The threshold for dry beans is when heavy stippling on lower leaves occurs with some stippling
progressing into middle canopy. Mites may be present in middle canopy with scattered colonies
in upper canopy. Leaf yellowing on lower leaves common.
If fields are above the action threshold for spider mites, then an insecticide or a miticide treatment may be necessary. Most of the insecticides and miticides available for control of spider mites in dry beans are listed here on page eight.

Dry Bean Scene

Grasshoppers and spider mites are just a couple of the pests dry bean growers should be on the lookout for. Learn more from NDSU Extension entomologist Janet Knodel in the latest Dry Bean Scene. This radio program is made possible, in part, by the Northarvest Bean Growers Association.

NDSU Crop and Pest Report

The seventh issue of the NDSU Extension Crop & Pest Report for 2021 has been released. Topics featured in this week’s edition are:
  • Insect Scouting
  • Disease Control
  • Splash Damage
  • Blister Beetles
  • Conditions Around the State
  • Weather Forecast