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!

 

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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

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

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

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

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

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

Crop report July 1

Weather conditions

(1) Septoria leaf blotch, (2) stripe rust, (3) black chaff, (4) Fusarium head blight (scab)
(1) Septoria leaf blotch, (2) stripe rust, (3) black chaff, (4) Fusarium head blight (scab)

It is getting warmer and dryer in SW Nebraska. Last week we received 0 to 0.8 inches of precipitation, while reference evapotranspiration (ET) losses dropped 2 inches. Many farmers are irrigating corn and other crops to build up the soil moisture profile so they can keep up with water demand during the peak of the growing season. Awoid chemigating roads and neighbor fields. Wheat Most of the wheat is at dough stage, but harvest will start next week in some areas! Hard winter kill in some areas, dry early spring and very wet April and May created favorable conditions for diseases that we don’t usually expect in this semi-arid climate to develop to flourish. Many farmers were not ready for it and diseases like black chaff, stripe rust, Fusarium head blight (scab) and Septoria leaf blotch are going to cause severe yield reductions. We learned that knowing varieties you planted is the best way to fight diseases; if variety is susceptible to stripe rust, be ready to spray.

Cultivation was used to control kochia in popcorn
Cultivation was used to control kochia in popcorn

Corn Corn is at V3 to V10 growth stages. Fields reveal the consequences of planting in wet conditions. Restricted root growth due to compacted seed bet is very common. Rootworm injury has been observed in continues corn. Look at which Bt-protein is expressed in your Bt-corn hybrid. If eCry3.1ab, mCry3A or Cry13Ab1 proteins are not expressed in your hybrid chemigate with Capture LFR or Brigade to control larvae of the rootworm. Even though, tillage and cultivation are a big “NO” in this part of the country, popcorn producers started cultivating due to lack of options to control kochia and Plamer amaranth.

PPO herbicide injury in soybean
PPO herbicide injury in soybean

Soybean Soybeans are at V1-V6 growth stage. Time to inspect soybeans for nodulation. Cut nodule in half and if color of tissue is pink, nodules are active and nitrogen fixation is present. Kochia is very hard to control and it’s gaining biomass rapidly with warm weather. Severe herbicide injury has be observed on soybeans in this area. Avoid applying generic herbicides that you haven’t used before at high temperatures to reduce the risk of hearting a crop. Other crops Milo from emergence to V6. Field peas are filling pods. Potatoes are in tuberization stage. Dry beans are at VE-V3 and in good condition. Sugarbeets are at 75% cover, and some insect damage and Cercospora leaf spot is visible on leaves, but no management action is needed at this point.

dry beans at V2
dry beans at V2
field peas filling pods
field peas filling pods
sugarbeeets at 75% cover
sugarbeeets at 75% cover

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

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