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Extension > Minnesota Crop News > June 2010

Tuesday, June 22, 2010

Feekes 10.51: A Pictorial

The recommended timing for fungicide applications to suppress Fusarium head blight or scab is Feekes 10.5 in barley and Feekes 10.51 in wheat. At growth stage Feekes 10.5 the inflorescence or spike is completely emerged from the boot. Photo 1 shows the progress of the heading process in barley. The third kulm is at Feekes 10.5 and the correct growth stage to receive a fungicide to suppress FHB. Photo 2 shows the progressing of the pollen shed in durum wheat; in the first kulm no anthers are visible on the outside of the individual florets, while in the second kulm the anthers are only visible in the center section of the spike. As these anthers are still yellow, they likely shed pollen earlier that day. In the third pollen shed is complete as anthers are visible across the length of the spike and are bleached and desiccated. The second photo closely approximates Feekes 10.51. The progression in spring and winter wheat is identical to the progression in durum wheat.

Purple Auricles in Wheat

The auricles in wheat are defined as the clasping appendages or the claw-like projections that are located at the junction of a leaf sheath and the leaf blade. Auricles in combination with the shape of the ligules are two anatomical features used to distinguish grassy species from another, such has in this identification key.

The auricles on most of our wheat and barley varieties are pale green. A few recent releases have purple auricles. Below is a close-up picture of the auricles on the cv. 'Faller'. This coloring is the result of the presence of anthocyanins and is a heritable trait. Expression of the trait is, however, not stable and you may find different levels of coloring from year to year. There is no reason to be concerned about this coloring.

10 Purple Auricle.JPG
Photo 1: Purple auricles on the cv 'Faller'.

Monday, June 21, 2010

Late Season N in Wheat - The Cliff Notes Edition

Based on the number of phone calls I received in just the last few days there is a considerable amount of interest in late season application of nitrogen with the goal to improve the grain protein content of spring and winter wheat. This interest isn't surprising given the extremely low grain protein concentrations of last year's crop and the crippling discounts that followed. Foliar applications of N during the onset of kernel fill have shown to be able to increase grain protein. A review article and decision guide were published in 2006.

Monday, June 14, 2010

Risk of Fusarium Head Blight in Wheat on the Rise

Wheat crops in the flowering stage are now at risk for FHB infection across most of the state, with highest risk in the NW region of MN. Winter wheat either already flowered or is flowering now, while some of the first planted spring wheat is close to flowering.

Risk is highest for susceptible to very susceptible cultivars. The 24-72 hour forecast indicates that the risk will remain or even get higher in the next few days.

Sign-up for Fusarium Head Blight Alerts

Producers and ag professionals that are interested in the potential risk for Fusarium head blight in wheat and barley can sign-up for a national alert system. These alerts are delivered either short text messages (SMS) on mobile phones or as e-mail messages.

Go to the National Scab Initiative website (http://scabusa.org/fhb_alert.php) and chose which way you would like the alerts to reach you and from which state or states and regions you would like to receive the alerts.

These alerts are made possible through the collaborative effort of the US Wheat and Barley Scab Initiative and the national FHB Prediction Center at the Pennsylvania State University.

The alerts for Minnesota will be provided in collaboration with Marcia McMullen, NDSU's extension plant pathologist, and others in the region.

Thursday, June 3, 2010

Control of Volunteer Soybean in Corn

By Jeff Gunsolus

This week I have received several inquires about the presence and potential impact of volunteer soybean in corn and cost-effective control procedures.  The scenario of volunteer soybean in corn is a fairly recent phenomenon due to the wide-spread use of the glyphosate-resistant technology in corn and soybean.  As a result, to my knowledge, data on corn yield loss potential as a function of volunteer soybean density is not available.  However, I do know of one NDSU study conducted by Dr. Richard Zollinger that does evaluate several herbicide options to control volunteer soybean in corn. You can find a general summary titled Control of Volunteer Roundup Ready Crops at:
http://z.umn.edu/ndweedguide and click on Weed Control Ratings.

Wednesday, June 2, 2010

Yellow Wheat

Jochum Wiersma, Small grains specialist

History repeats itself ever so often and unfortunately excess precipitation in many part of the Red River Valley has caused once again overland flooding and saturated field conditions. Wheat and barley can handle some flooding but it is not without a cost. As the water recedes and the soils drain you will likely notice that the wheat crop (and barley for that matter) has turned pale green or even yellow. In 2008 Doug Holen, Dan Kaiser and I wrote a short a summary of the causes of this yellowing and the possible solutions. Below is a nearly complete reprint is that article:
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