Iron Deficiency Chlorosis in Soybean
Hello! I hope you’re having a great day.
We received rainfall again in the past week. We received on average 1.5 inches of rain. Temperatures were normal to above normal in the past week.
Because of the rain harvest is still continuing. About 90% of the soybeans have been harvested and about 30% of the corn have been harvested.
I have a program that will be offered called Annie’s Project. This is a multi-county program that will be offered from November 15, 2021 to February 28, 2022 for six weeks in Hatton, North Dakota. The mission of Annie’s Project is to empower women in agriculture to be successful through education, networks, and resources. To register for the event visit the following website: www.tinyURL.com/APHatton . If you have questions about the program call the Griggs County Extension Office at 701-797-3312.
Iron deficiency chlorosis happens in Griggs County, but not too often.
Iron deficiency chlorosis in soybean is caused when the soil pH is high. The higher the soil pH gets the more insoluble iron becomes making it less available to the soybean plant to be picked up, resulting in a deficiency. Our soils actually has enough iron, it is just not available to the soybean plant.
Iron deficiency chlorosis shows up in new leaf tissue as an interveinal yellowing to whitening while the veins remain green. As the deficiency progresses, leaf tissue and even the growing point can die.
Soil conditions which are prone to iron deficiency chlorosis are: high pH soils containing calcium carbonate; cool and wet soils; poor drainage; saline soils; and high nitrogen fertility level fields. Other non-iron related soybean yellowing causes are loss of sulfur, poor inoculation of first-year soybean fields or soybean cyst nematode.
If iron deficiency chlorosis symptoms are observed, the best course of action is to take note of problem fields for future management plans and just wait for sunnier days. Rescue iron chelate sprays are not economical and not recommended.
Recommended practices to reduce iron deficiency chlorosis is to choose a tolerant soybean variety, apply an ortho-ortho-EDDHA fertilizer at planting, such as Soygreen, plant in wider row spacings, use a cover crop at the time of soybean seeding, and not to apply nitrogen to the soybeans or at least choosing fields having lower residual soil nitrate levels. Managing crop drainage and salinity levels also can improve conditions.
Use only ortho-ortho-EDDHA fertilizers at planting. Other forms of EDDHA do not increase the solubility of the iron.
Research by North Dakota State University in 2021 looked at the sensitivity of soybean varieties to iron deficiency chlorosis at one location. The soybeans were visually evaluated and given an iron deficiency chlorosis score of 1 to 5 with 1 being green, 3 being yellow, and 5 dead tissue.
The soybean varieties with the lowest scores were SB8903N from Thunder, LS-0239 RR2X from Legacy, and XT80-20N from Proseed at a rating of 1.1. Other soybean varieties having statistically similar iron deficiency chlorosis ratings include 21ND008GT20 from NDSU and S03XT29 from Dyna-Gro at 1.2, S04-Q7X and NK04-G8E3 from Syng NK at 1.3, 009E955N from Legend, 50309N from Integra, 0320R2X from Channel, and Rolette from NDSU at 1.4, GH0443X from Golden Harvest, S008-E3 form Syng NK, and A0338X from Innvictis at 1.5, and LS-044-21XF from Legacy and GH0452E3 from Golden Harvest at 1.6. Z08801E from Hefty had the highest rating at 3.8. For ratings of other soybean varieties tested visit https://www.ag.ndsu.edu/varietytrials/fargo-main-station/2021-trail-results/2021-ndsu-enlist-gt27-roundup-ready-and-xtend-soybean-iron-deficiency-chlorosis-trial/view .
First look at variety tolerance to iron deficiency chlorosis then consider an application of ortho-ortho-EDDHA at planting to managing iron deficiency chlorosis.
Have a great day and weekend!
