Consider threat of seedling diseases in soybeans

decrease font size  Resize text   increase font size       Printer-friendly version of this article Printer-friendly version of this article

With soybean planting almost complete in South Dakota, Connie Strunk, SDSU Extension plant pathology field specialist, reminds growers to scout their fields for seedling diseases as plants begin to emerge.

"Even though most soybean seed has been treated with a fungicide seed treatment, no seed treatment product is effective against all seedling diseases and under all conditions," Strunk said. "It is important to look at what protection the seed treatment offers and the performance it delivers."

Most seed treatments offer a limited time of protection against seed and seedling diseases. Depending on soil temperature and soil water content, the chemicals are effective for about two weeks after planting.

"Damping off can occur in two ways; before emergence, where the seedlings fail to emerge because of a fungal attack, or post-emergence, where the seedlings are killed by fungal attack after emergence," Strunk said.

If your soybean field has been affected by seedling blight or damping off, Strunk says it is helpful to identify what seedling disease caused the infection. Proper diagnosis will help with fungicide seed treatment selection for replanting purposes and even for next year's planning.

The two fungi most often associated with damping-off in South Dakota soybean fields are Pythium and Phytophthora. Strunk says it is difficult to distinguish between these two seedling blights without lab testing.

"Phytophtora typically has a brown discoloration extending from the soil line up the stem of the soybean plant. Pythium attacks soybean seedlings planted in cold, wet soil whereas Phytophthora attacks soybean seedlings in warm weather generally around 80F," she said.

She adds that Rhizoctonia is another seedling disease that attacks soybean seedlings in warm weather (80F) and is often seen in late-planted soybean fields.

"With Rhizoctonia you will often see a reddish-brown colored lesion on the hypocotyl and lower stem of the plant but this is not observed above the soil line," she said.

Buyers Guide

Doyle Equipment Manufacturing Co.
Doyle Equipment Manufacturing prides themselves as being “The King of the Rotary’s” with their Direct Drive Rotary Blend Systems. With numerous setup possibilities and sizes, ranging from a  more...
A.J. Sackett Sons & Company
Sackett Blend Towers feature the H.I.M, High Intensity Mixer, the next generation of blending and coating technology which supports Precision Fertilizer Blending®. Its unique design allows  more...
R&R Manufacturing Inc.
The R&R Minuteman Blend System is the original proven performer. Fast, precise blending with a compact foot print. Significantly lower horsepower requirement. Low inload height with large  more...
Junge Control Inc.
Junge Control Inc. creates state-of-the-art product blending and measuring solutions that allow you to totally maximize operating efficiency with amazing accuracy and repeatability, superior  more...
Yargus Manufacturing
The flagship blending system for the Layco product line is the fully automated Layco DW System™. The advanced technology of the Layco DW (Declining Weight) system results in a blending  more...
Yargus Manufacturing
The LAYCOTE™ Automated Coating System provides a new level of coating accuracy for a stand-alone coating system or for coating (impregnating) in an automated blending system. The unique  more...
John Deere
The DN345 Drawn Dry Spreader can carry more than 12 tons of fertilizer and 17.5 tons of lime. Designed to operate at field speeds up to 20 MPH with full loads and the G4 spreader uniformly  more...
Force Unlimited
The Pro-Force is a multi-purpose spreader with a wider apron and steeper sides. Our Pro-Force has the most aggressive 30” spinner on the market, and is capable of spreading higher rates of  more...
BBI Spreaders
MagnaSpread 2 & MagnaSpread 3 — With BBI’s patented multi-bin technology, these spreaders operate multiple hoppers guided by independent, variable-rate technology. These models are built on  more...

Comments (0) Leave a comment 

e-Mail (required)


characters left

Tube Series (TS) Conveyors

USC’s Tube Series Conveyors combine the gentleness of the signature Seed Series with the traditional stability of a tube-style conveyor, ... Read More

View all Products in this segment

View All Buyers Guides

Feedback Form
Feedback Form