Take all disease of wheat

Hi all,

I had a number farmers reporting diseased wheat in fields at harvest time. Specifically, darker colored wheat plants and empty wheat heads. These symptoms may be mistakenly identified as loose smut, seed borne disease – which is controlled during wheat seed certification process, and with fungicide seed treatments. If this is your common management practice, probability of having loose smut is 99.99%! I would not neglect possibility of this disease in your field if you planted bin-run seed that was not treated.

This is more likely TAKE ALL disease that was pretty common this year due to wet spring. If you try to dig the pant out, it would have damaged or no roots and lover stem will be dark in color (see 3rd picture below). It showed on both certified and bin-run seed in our plots at Stumpf Wheat Center near road ditch that had standing water for 2 days in spring. Plots were planted behind fallow with wheat stubble in it.

Disease is residue-borne more likely to be present in wheat-fallow rotations, and wet areas of the field (low drainage, compaction, heavy-textured soils). Wheat dies prematurely, so it appears white during grain fill period (instead of being green) and back at harvest (instead of being yellow/gold). Pathogen also survives on downy brome and other grassy weeds that may be in in ditches. Disease has potential to wipe out the whole field.

For management do rotate your wheat with corn, sorghum, peas, etc., give residue time to break down, and control grassy weeds!

Glad to see a lot of good wheat around! Not so glad to see discounts at the elevator! Learn to live by faith or die!


Hail storm – Perkins Co, Nebraska

Hail storm hit areas of Perkins County, NE (Venango and west). Damaged houses, windows, vehicles, crops… Photo courtesy goes to: Chandra Grothman Davidson, Nancy Reynolds, and Preston L Case.

Crop Report May 3-17




Weather conditions

In past two weeks, SW Nebraska received about 1 inch of precipitation, average air temperatures raged between 45 F and 65 F generating 123 GDD (growing degree days), soil temperatures had a gradual increase from 50 F and currently are at 58-62 F.

Corn planting and emergence progress

Picture 1. Emerged corn looks yellow in SW Nebraska
Emerged corn looks yellow due to lack of sunshine and cool temperatures

Most of the farmers are finishing up corn planting. There is about 20% corn acres yet to be planted and roughly 20% already emerged. Early planted corn emerged well despite the low soil temperatures. Strips that were tilled for corn to be planted consistently had higher reading then data from the weather stations, thus no injury occurred in most places. Corn plants, however, do look pale and yellow in color due to lack of sunshine and temperatures, but will grow out of it with warmer weather to come (Picture 1). To asses corn replant options due to poor emergence click here.


Wheat is generally in good conditions and is pushing flag leaf. There are reports of isolated stripe rust infections in SW Nebraska and preventive areal fungicide applications started this week (Picture 2). Applications prior to flag leaf emergence are not advised. If farmer has a stripe rust resistant variety, regular scouting and prolonging fungicide application by 10 days or so may provide long enough residual activity of fungicide to protect the flag leaf and avoid second fungicide application later on in the season.

Wheat is showing signs of nitrogen deficiency. Yellowing of the leaves is common in low areas of the fields with standing water and poor drainage conditions. In addition, sporadic yellow spots may be found throughout the field due to nitrogen that has been leached bellow the root zone (Picture 3).

Picture 3a. Nitrogen deficiency in wheat
Picture 3. Nitrogen deficiency in wheat

Picture 3b. Nitrogen defficient wheat leaves

Field peas

Field peas are relatively new crop in western Nebraska with promising agronomic potential and growing national and international markets. UNL Extension partnered with 5 farmers to receive USDA SARE (Sustainable Agriculture and Research Education) grant and investigate agronomic issues related to field pes production in SW Nebraska. Weed control is one of those issues and it will be interesting to see how well field peas compete against kochia (Picture 3). Field peas are at 3-5 leaf stages. For more information on field peas click here.

Picture 4. Field peas at V3 competting with kochia
Picture 4. Kochia infested field peas field

Educational oportunities in SW Nebraska

PicMonkey Collage - Jan 28

Below is a snapshot of 4 Educational opportunities in SW Nebraska. For more information contact Strahinja Stepanovic, email: sstepanovic2@unl.edu, phone: 402-318-1124

1. WC Cattleman’s Day

Joint Program of NE Extension and CSU Extension developed for cow/calf producers. This conference should help you find ways to reduce cost while helping to improve your overall profitability. Speakers and Topics:

  1. Robert Tigner, NE Extension Educator – Managing Replacements to Maximize Heifer Values. Can You Afford to Re-build your Herd?
  2. Randy Sander, NE Extension Educator – Increasing Reproductive Efficiency of the Cow Herd
  3. Chris Shelly, CSU Livestock Agent – From Mineral Supplementation to Cattle Transportation
  4. Troy Waltz, NE Extension Educator – Grazing System Management and Using Annual Forages
  5. Strahinja Stepanovic, NE Extension Educator – Forage kochia

Registration: $20 at the door, $15 if preregistered by Jan 28

Refreshments: supper included


Time Location Address
3-Feb 5:00-8:00 pm MT Cross Roads Wesleyan Church

1710 Wesley Drive, Imperial, NE

2. On-farm Research Update

Find out results of 16 on-farm research studies conducted in SW Nebraska addressing issues such as growing field peas, fertility management in high ph soil, soybean row spacing, and testing growth enhancement products. Learn about projects from other parts of the state on topic such as: variable rate seeding, planting populations, Maize-N nitrogen rate decision tool for sidedress nitrogen, starter fertilizer, fungicide applications, row spacing, cover crops, foliar micronutrients, seed treatments, and others.

Registration: not required.

Refreshments: lunch included


Time Location Address
8-Feb 12:00-4:30 pm CT West Central Research and Extension Center (WCREC)

402 W State Farm Rd, North Platte, NE

3. Irrigation scheduling tools and maximizing irrigation performance

Learn essentials on maximizing irrigation performance and utilizing various tools for irrigation scheduling such as evapotranspiration (ET) gauge and soil moisture sensors. You will also receive an update on our Extension programs that address water issues and have the opportunity to participate in them (we will give you ET gauges to try them out) so we can together contribute to the wellbeing of our community. Speakers:

  1. Strahinja Stepanovic, NE Extension Educator
  2. Chuck Burr, NE Extension Educator
  3. Dr. Daran Rudnik – UNL Irrigation Specialist

Registration: not required

Refreshments: provided


Time Location Address


9:00-11:00 am MT Stumpf Wheat Center 76025 Road 329, Grant, NE
1:30-3:30 pm MT Chase County Extension Office

135 W 5th street, Imperial, NE

5:00-7:00 pm MT Dundy County Courtroom

112 W 7th Ave, Benkelman, NE

4. Weeds, Insect and Disease Resistance Workshop

Unique opportunity to learn from University specialists and local crop consultants from our region about the importance of herbicide, insecticide and fungicide resistance management, mode of action, and how to use this information to reduce spread of weeds, insects and plant pathogens in Nebraska. Speakers and topics:

  1. Stevan Knezevic, UNL Weeds Specialist
  2. Julie Peterson, UNL Entomology Specialist
  3. Anthony Adasemoye, UNL Pathology Specialist

Registration: required, online: http://agronomy.unl.edu/pest-resistance

Refreshments: lunch provided

Date Time Location Address
10-Mar 10:00-3:00 pm MT Stumpf Wheat Center 76025 Road 329, Grant, NE



Crop and Water report 08-25 to 08-31

It has been three weeks since we had our last rain in SW Nebraska and we are seeing all dryland crops showing signs of drought. Reference evapotranspiration (ET) in the Upper Republican NRD ranged from 1.6 inches in Perkins Co to 2.9 inches in SW Dundy Co. This means that crops in SW Dundy Co used about 1.5 inches of water more than in Perkins Co. See image for more details on ET and rain data as well as crop growth stages and their water use coefficients for this period.

ET and rain data 08-25 to 08-31

According to US Drought monitor none of the Counties in SW Nebraska are in abnormal drought, which can means that these conditions are (believe it or not) normal in SW Nebraska this time of the year. According to 30-year weather data, average August precipitation and ET are 2.50 and 9 inches, respectively. This means that the area had the August weather conditions in very close proximity to long term average.

We had very good growing conditions in May, June, July and August, so crops used all that water and heat to produce large biomass and increase yield potential. Rain is much needed to keep up with high water demands during the grain filling period in September, otherwise we will have to be satisfied with the mediocre dryland yields at the end of the year.

Crops and Water report 07-21 to 07-27

Weather and crop water use

Reference evapotranspiration (ET) in the Upper Republican NRD ranged from 1.70 inches at north parts of Perkins County to 2.20 inches in south Dundy County; we received between 0 and 1.70 inches in rain. To more accurately estimate rain and crop water use on your farm, look at the map provided, obtain weekly reference ET value from location closest to you and multiply that value by crop coefficient provided in the table.

ET and rain 7-21 to 7-27

Weeds control in wheat stubble

Strip of uncontrolled downy brome next to the wheat stubble will cause problems in the future
Strip of uncontrolled downy brome next to the wheat stubble will cause problems in the future

Time to control weeds in the wheat stubble! New Cropping systems specialist from Panhandle Research and Extension center, Cody Creech, suggested 3 steps to control weeds in wheat stubble: (1) Carefully identify weeds that are present in your field, (2) spray weeds kochia, Palmer pigweed, pricly lettuce, Russian thistle and other tough to control summer annuals with tank-mix of glyphosate, dicamba and/or 2,4-D to prevent seed development (3) monitor for winter annual weeds like rye, marestail and cheetgrass and plan timely herbicide application in fall and early spring. For more information click here.


Corn is at reproductive growth stage. Adults of Western Bean Cutworm have been emerging in past week and spraying has been done in the area. UNL’s recommended threshold for insecticide application is 5-8% of corn plants have egg masses and/or small larvae.

Western bean cutworm egmass
Western bean cutworm egmass

Other crops

Sunflowers are at V5 to butonization stage. Field peas harvest is done. Soybeans are at R2-R4 growth stage (setting pods). Milo is at booth stage. Potatoes in tuberization stage. Dry beans are at 80%-full cover. Sugarbeets are at full cover.

Crop report July 21

Weather and crop water use

Isolated t-storms delivered from 0.2 to 1.8 inches across Upper Republican NRD. Reference evapotranspiration (ET) losses were 2.0 inches on average. To estimate crop water use on your farm look obtain weekly reference ET value from location closest to you and multiply that value by crop coefficient provided in the table.

ET and rain 7-13 to 7-20
ET and rain 7-13 to 7-20


Wheat harvest is 95% done! Dryland yields range from 20 bu/ac to 90 bu/ac. Farmers that had hard winter kill and didn’t spray wheat for stripe rust had lover yield and lower test weight (about 53-55 lbs/bu). Wheat kernels diseased with ergot and/or Fusarium head scab have been observed. Although these did not appear to be a major yield limiting factor wheat can affect marketability of wheat seed. Loads can be rejected at the elevator if 0.05% of wheat kernels have ergot (about 0.5 oz/bu) or if over 1 ppm concentration of DON toxin has been detected in Fusarium-damaged kernels. Setting up your combine to blow out “chaffy” seed take care of this problem.

Ergot in wheat
Ergot in wheat
Wheat kernels infested with Fusarium head scab
Wheat kernels infested with Fusarium head scab


Corn is at V14 to tasseling growth stage. Adults of Western Bean Cutworm have been emerging in past week. If 5-8% of corn plants have egg masses and/or small larvae, consider an insecticide application either through a center pivot irrigation system of by airplane. It may be beneficial to select an insecticide that controls both spider mites and Western Bean Cutworm as mite populations are increasing in the area. Resistance of Western Bean Cutworm to proteins expressed in transgenic corn has been observed in SW Nebraska. Only the Bt corn hybrids containing Cry1Ftoxin (e.g. Herculex I, Herculex XTRA, SmartStax) are effective in controlling the pest. For more information on Western Bean Cutworm and its management click here.

Other crops

Field peas harvest is in progress; dryland yields of 40 bu/ac have been reported. Soybeans are at R1-R3 growth stage. Milo from V8 to booth. Potatoes are in tuberization stage. Dry beans are at 50-80% cover. Sugarbeets are at full cover.

40 bu field peas harvested from this on-farm research study
40 bu field peas harvested from this on-farm research study

Schedule your irrigation based on crop water use

Nebraska Ag Water Management Network (NAWMN) is a collaborative group of farmers, crop consultants, NRD personnel and UNL Extension Educators that work together across the state of Nebraska to adopt water and energy conservation practices.

This is done by using simple WATER BUDGET equation. To keep up with WATER DEMAND (crop water use) we need to receive equivalent amount of moisture on WATER SUPPLY side of the equation, which includes soil available moisture, rain, and ultimately irrigation. Unfortunately, we can only control irrigation component of this equation. In the following paragraphs I will discuss how we can use newer technologies how to make every inch of water applied through irrigation to produce yield.

June 15 to June 21

This summer SW Nebraska adds about 15 locations collaborators (farmers and crop consultants) from Perkins, Chase and Dundy Counties to more accurately estimate WATER DEMAND (crop water use). Map of potential evapotranspiration (ETo) will be posted weekly in your newspaper, on radio, water.unl.edu website, on this blog, or twitter @agwithstrahinja. To estimate crop water use or crop ETc look at the map provided, obtain weekly ET value from location closes to your farm and multiply that value by crop coefficient provided in the table. Assuming your soil has enough moisture on the supply side this is how much water your crop used in a past week.

To accurately estimate WATER SUPPLY, first you need to know how much rain you received in the past week. Along with ET values we also provide rain data. However, keep in mind that rain can very much more from one place to other then ET.

Second, you need to know water holding capacity of your soil. For example, silt loam soil can hold 2.2 inches/ft while loamy sand can only hold 1.1 inches/ft. Research showed that plants start to loose yield due to water stress after soil water is more than 50% depleted. Therefore, in silt loam soil you have about 1.1 inches/ft more to manage then in loamy sand (4.4 inches if 4 foot profile). Chart with waterholding capacities of different soil type and trigger levels for irrigation can be downloaded here.

Second, you need to know how much water you have in your soil, and soil moisture sensors can help you with that. UNL did research that enabled us to use readings from Watermark sensors (in cb) and convert to inches/foot. Watermark sensors are very affordable (about $35 each) and accurate, and over years we learn to trust them. More about using Watermark sensors click here.

Example for irrigation scheduling based on ETc. Last week corn started with soil at field capacity and now is at V8 growth stage and it used 0.7 inches of water based on weekly reference ETo (1.5 inches) x crop coefficient Kc for V8 corn (0.5). Corn is grown on loamy sand that has waterholding capacity of 1.2 inches/foot, and at this time corn rooting depth is 2 foot. We want to keep our soil above 50% depletion to avoid water stress; thus, we have 1.2 inches in top 2 foot to manage (0.6 inches/foot x 2 foot). There was no rain last week, so there is 0.5 inches left in soil profile (1.2 inches/soil profile – 0.7 inches for ETc). In hot summer day corn at V8-V10 stage can easily take up 0.5 inches in 2 days; therefore, in this scenario (assuming there is no water allocation) irrigation is recommended to avoid water stress.

Crop report June 18

Weather conditions

About 1 to 1.5 of precipitation has been received in past week. Nitrogen leaching is a concern! About 50-70 lbs/ac of nitrogen has been found in 3rd and 4th foot of soil profile that is probably not going to be taken up by the crop. Taking a soil test is recommended to determine how much nitrogen has been lost and make corrections on your in-season nitrogen management plan.

Hail damage causing yield loss due to stand reduction

Storm carrying 1 inch of precipitation and pea size hail came across areas of Perkins and Chase on June 16. Assess hail damage to the crop before making replant decisions.

Corn plants without damaged growing point will recover with minor yield losses. In corn, growing point is under the soil surface until V5 to V6 stage; thus, protected from hail injury. If you have corn at >V5 knife to inspect the condition of growing point to accurately determine stand reduction.

Soybean has growing point at the tip of the plant, therefore small (V1-V3) soybean plants will not be able to recover after hail damage if growing point is damaged. Larger soybeans may be able to continue growing from semi-dormant axillary buds located inside the leaf axils at first 2 nodes when top of the main stem is cut-off.

Check UNL charts for determining yield loss due to stand reduction for corn, soybean and sorghum.


Wheat kernel at watery consistency
Wheat kernel at watery consistency

Wheat started filling grain. Kernels are in between watery consistency to milky ripe. With moisture and we had in past month it has been a paradise for spread of diseases, especially in dryland corners that didn’t received fungicide treatment. Leaves are often covered less than 50% with green healthy tissue. Good news are that this year we had enough moisture to make 100 bu dryland wheat (if rain patterns continue), which will overweight some yield loss coming from diseases and hopefully bring it to above long-term average.

Other crops

Corn growth stages range from emergence to V7. Milo from emergence to V4. Soybeans planting is 90% done and V2-V3 soybeans are found in the area. Field peas and flowering and grew about a foot in past week, potatoes are also flowering and in excellent condition, sugarbeets are at 50% cover.

Sugarbeets at 50% cover
Sugarbeets at 50% cover
Soybean at V2
Soybean at V2

Crop report June 10

Srpayer stuck in the muddy field
Sprayer stuck in the muddy field

Weather conditions

Less than 0.5 inch of precipitation in past 7 days have dried fields enough for farmers to continue planting and spraying weeds. Assess wetness of your field carefully!!! Planting in wet soils can cause severe crusting and problems with crop emergence, especially in soybean. Avoid spraying wet areas with heavy equipment. Mark them with flag and spot-spray with ATV  sprayer.

Water management

Irrigating wheat is recommended to keep up with the water demand. On the 85-90 F days we had on 06-09-2015 wheat uses 0.37 inches per day, which is 2.59 per week. Wheat extracts water from top 3 foot, which means that you need approximately 0.9 inches/foot/week to meet the wheat water requirements. Most of our silt loam soils can hold 0.7 inches/foot at field capacity, which means that wheat will start showing water stress at 0.35 inches/foot (50% depletion). In other words, irrigators on a typical soil in SW Nebraska have an irrigation management span of 1 inch (in top 3 foot) to avoid water stress.

In summary, you will need 2.59 inches on demand side and available soil moisture + rain + irrigation on the supply side of equation. Frequent irrigations at 0.5 inches irrigation depth are typically recommended to allow water infiltration and avoid runoff. Probe or use soil moisture sensors to estimate what you already have in the soil get you in the ballpark.


Wheat is at flowering stage. Hail damage observed in west Chase County. Stripe rust is moving north and is now observed in Perkins and Keith Counties. Fusarium head blight (head scab) has not been observed jet, but treating your wheat with Caramba and/or Prosaro is recommended to keep flag leaf protected from disease. Check Nebraska Extension article on “Distinguishing between head disorders of wheat” to correctly identify head scab.

Hail damage (1st and 2nd picture), stripe rust and Black chaff on whaeat in SW Nebraska
Hail damage in Chase Co (first 2 pictures), stripe rust (3rd picture) and Black chaff (4th picture) in Perkins Co

Black Chaff is a seed-borne bacterial disease that started showing up in fields where bin-run seed of susceptible varieties has been planted last fall. No treatment is recommended to control Black Chaff; planting tolerant variety and certified, pathogen-free seed are the best strategies to prevent yield losses caused by Black Chaff.

Seedling disease in corn
Seedling disease in corn


Corn growth stages range from emergence to V4. Soil borne diseases have been observed in SW Nebraska; popcorn seems to be more susceptible then field corn. Assess your field carefully for stand reduction before making decisions on replanting. Economic threshold for replanting irrigated corn planted at 32,000 seeds/ac is about 20,000 seeds/ac (about 45% in stand reduction). As fields are drying out we see more applicators spraying weeds that have been growing wild in past couple weeks. Amaranth spp. (pigweed species) started emerging.

Flowering canopies of field peas (1st pic), potatoes (2nd pic) and wheat (3rd pic). Once you see potato flower you will never forget it!
Flowering canopies of field peas (1st pic), potatoes (2nd pic) and wheat (3rd pic). Once you see potato flower you will never forget it!

Other crops

Soybean are cracking and planting is about 55% done. Planting in wet conditions can cause crusting in some areas. If crusting about