Dodge County Crop Tour – Mid July

Dodge County Crop Tour Route from July 18, 2016

Figure 1. Dodge County Crop Tour Route from July 18, 2016. Stopped at 24 fields along the 99 mile route.

View previous mid-July crop tours from July 14 and July 21, 2014 and July 16, 2015 

In this report, I will use the definitions used by USDA-NASS for crop conditions:

USDA Crop Condition Ratings:

  • Very Poor:  Extreme degree of loss to yield potential, complete or near crop failure.
  • Poor: Heavy loss of yield potential due to excess soil moisture, drought, disease, etc.
  • Fair: Less than normal crop condition. Yield loss is a possibility but is not severe.
  • Good: Yield prospects are normal or above. Moisture levels are adequate with minimal disease and insect damage.
  • Excellent:  Yield prospects are above normal and crops are experiencing little or no stress.

Summary of the 6 soil-landscape regions of Dodge County (see pictures and report below from each region):

Corn: The corn crop is mostly in good condition across the county.  Areas where the corn is in very poor to poor condition were created by flooding and waterlogged soils in the Pebble, Maple Creek, and Platte River bottoms. Variable plant populations in early planted (April 11-17) corn from both emergence issue and seedling damping off has resulted in some irrigated fields with ear counts in the low 20k range, leading to these acres to be in only fair condition. The early planted corn is in the R2 (blister) stage is putting on good size ears (18 rows x 42 kernels long) at these lower plant populations. The May planted corn is in the V18 to R1 (silking) growth stage and is in good to excellent condition, particularly where green snap from the July 5 storm did not occur (Figure 2). Green snap, pinched stems, lodging, and hail damage occurred on about 75,000 acres of corn in the county. Therefore, those impacted fields range from poor to good condition.  There were definitely some corn fields planted in early May that missed the storm damage that are in excellent condition. The corn crop is largely disease free with only low levels of common rust and Holcus spot.  I only found gray leaf spot in 2 of the 14 fields I stopped in (Stop 15 and 24), which reflects other reports of low gray leaf spot pressure around the state this year. Fungal diseases like gray leaf spot do not need wounds to infect the plant. However, bacterial diseases like Goss’s Wilt could infect wind and hail-damaged fields. To state the obvious, a fungicide won’t control a bacterial disease. Luckily, more hybrids have better resistance to Goss’s Wilt than in years past. As for insects, southern, northern, and western corn rootworm beetles can now be found in corn fields.  I only saw northern corn rootworm in the northwest corner of the county and western corn rootworm in corn-after-corn fields. A newer insect we need to watch in coming years is the Japanese beetle that can clip silks.

My corn condition ratings on Monday, July 18:
Very Poor – 1
Poor – 4
Fair – 10
Good – 70
Excellent – 15

Corn all progress:
75% silking

Soybeans: The soybean crop is good to excellent condition on most acres. Even though many wet spots were replanted to soybeans, more than once in some cases, we don’t have the amount of prevented planting acres like we did in 2015. The wind damage from the July 5 didn’t cause much soybean damage.  Hail damage from events on June 20, July 5, and July 18 did impact some acres, but not to the extent we had with the corn. Our range in growth stages is very similar to last year, V2 (two trifoliolates) to R3 (beginning pod). Narrow row and some 30″ row soybean fields are already canopied and are 30 to even 40 inches tall. As far as soybean diseases, only bacterial blight was of any significance.  Bacterial blight (Figure 2 below) will be curtailed this week with the hot weather and rarely is a disease the impacts yield. Brown spot, which affects the lower canopy, is less severe than normal. I didn’t observe any frogeye leaf spot in the fields I stopped at, unlike last year. There are numerous different insects causing defoliation this year, but even as collective whole they are not defoliating leaves at sufficient levels to warrant treatment at this time (threshold in near 20%).  Bean leaf beetle, southern corn rootworm, Japanese beetle, yellowstriped armyworm, alfalfa caterpillar, and grasshopper species were the most frequently found defoliators this year. The soybean crop is largely made during August, but our July soybean crop looks good right now.

My soybean condition rating on Monday, July 18:
Very Poor – 0
Poor – 1
Fair – 4
Good – 75
Excellent – 20

Soybean progress:
95% blooming
20% setting pods

Three agronomic insights for the coming weeks:

  1. Scout soybean fields for defoliation (calibrate yourself on % defoliation, determine defoliation %, identify insect species) before spraying insecticides.
  2. Check your corn hybrid ratings for gray leaf spot resistance, talk with you seed dealer, and scout fields to better assess where a fungicide application will pay for itself.
  3. Determine crop water use and soil moisture status to help with irrigation scheduling. View Dodge and Washington counties crop water use and soil moisture status reports.

View previous mid-July crop tours from July 14 and July 21, 2014 and July 16, 2015 

Breakdown by Region (24 field stop pictures)

Platte River Valley (Fremont, Ames, North Bend)

The corn crop ranged from poor to excellent condition, with most of the crop being in good condition. The growth and development of corn ranged from V11 (11 visible collars) on late planted corn (Stop 3) to R2 – blister stage on early planted corn in the Platte River Valley (Stop 4). About 80% of the corn was silking, which is ahead of last year’s corn maturity in the valley. Overall, the corn crop is more mature and in similar condition as last year at this time. Insects found in corn fields included grape colaspis, western corn rootworm beetles, corn blotch leafminer, stinkbugs, and Japanese beetles (Stop 1). These insects were only causing very minor issues and do not warrant any action. There is very low fungal disease pressure compared to previous years with only a minor amounts of common rust pustules. The soybean crop was good condition ranging from poor  to excellent. The soybean growth and development ranged the V2 growth stage (Stop 2) to R3 – beginning pod. This was very similar to last year’s range in growth stages. However, we did not have the large amount of prevented planting acres like last year. Insects found in soybean fields included bean leaf beetles and grasshoppers. The only noticeable leaf disease was from bacterial blight (Figure 2) which should diminish with the warm weather this week.

Figure 2. Japanese beetle feeding on corn silks.

Stop 1 (Platte River). Irrigated tilled corn-after-corn field on Gibbon loam soil with 29k ears/acre. Japanese beetles where feeding on corn silks. This insect is becoming more common to find in fields compared to the last two years. Learn more about Japanese beetles at CropWatch.

 

Figure 3. Wet conditions this year caused numerous acres to be replanted. Soybeans V2 (two trifoliolates and R2 (full bloom).

Stop 2 (Platte River). Wet conditions this year caused numerous acres to be replanted. Soybeans were V2 (two trifoliolates and R2 (full bloom) in this field on Luton silty clay soils (poorly drained).

 

Late planted corn at V11 (11 visible collars) on poorly drained Luton silty clay soil.

Stop 3 (Platte River). Rainfed tilled corn-after-soybean field was late planted and is at the V11 (11 visible collars) on this poorly drained Luton silty clay soil.

 

Stop 4. Nice irrigated corn after corn field.

Stop 4 (Platte River). Irrigated tilled corn-after-corn field at the R2 (blister stage) on Gibbon silty clay loam soil. Plant populations on early planted fields were not ideal this year. There was 25k plants w/ears per acre.  With only 1k/acre green snapped. There were western corn rootworm beetles found in this field.

Figure 2. Bacterial blight

Figure 2. Bacterial blight visible on upper leaves. Read more about this bacterial blight at CropWatch.

Fillmore Flats (central Dodge County) – See Figure 3 below

The corn crop ranged from fair to excellent condition, with the irrigated corn crop in good condition and rainfed corn in good-excellent condition due to excellent topsoil and subsoil moisture (Local Crop Water Status). The growth and development of corn ranged from V18 (visible leaf collars) to R2 (blister). About 80% of the corn was pollinating. Seed corn looked good and mostly disease free. Many seed corn fields are in the R1 (silking) growth stage and are already detasseled.  Insects in found in corn fields were grape colaspis and corn blotch leafminer. Only low fungal disease pressure from common rust was observed. Green snap and pinched stems was a major problem through portion of this region (Stop 7 and 8). Green snap ranged from 3 to 25%. I had one report of seed corn with 70% green snap. The soybean crop was in fair to excellent condition, most soybeans in good condition. The soybean growth and development ranged from beginning bloom (R1) to beginning pod (R3). Insects found in soybean fields included bean leaf beetles and grasshopper species. The only disease observed was bacterial blight.

Stop 5. Irrigated soybeans-after-corn on tilled ground at the R3 growth stage.

Stop 5 (Fillmore Flats). Irrigated soybeans-after-corn on tilled ground at the beginning pod growth stage growing on Moody silty clay loam terrace soil. These soybeans in 30″ rows were canopied. Only minor leaf defoliation (<5%) from various insects.

 

Stop 6. Seed corn

Stop 6 (Fillmore Flats). Seed corn field at the R1 (silking) growth stage with a very healthy leaves (only common rust) growing on Moody silty clay loam terrace soil.

 

Stop 7: Green snap

Stop 7 (Fillmore Flats): Tilled irrigated corn-after-soybean field with 35K plants per acre (32K ears, 3K green snap) in the silking growth stage. Moody silty clay loam stream terrace soil. Damage in this spot was about 10%.

 

Stop 8: No-till corn

Stop 8 (Filmore Flats): Rainfed no-till corn-after soybean field at the silking (R1) growth stage with 27K ears per acre  growing on Moody silty clay loam river stream terrace soil.  Green snap of only 1K plants per acre in this spot. The lower leaves are very disease free for mid-July.

 

Stop 9. Soybeans

Stop 9 (Fillmore Flats). Rainfed soybean-after-corn field growing on Moody silty clay loam stream terrace soil. This field planted in 30″ rows was nearly canopied and 30″ tall. It was in the full bloom to early beginning pod growth stage. Very minor leaf defoliation (<1%) in this field.

 

IMG_5108

Figure 3. This is why I call the area in central Dodge County the “Fillmore Flats.”

Northwest Nora Loess Hills (near Snyder & Dodge)

The corn crop ranged from very poor to excellent condition, with most of the irrigated corn crop in good- excellent condition and rainfed corn in good-excellent condition. About 70% of the corn was silking. Some of the acres in the Pebble creek bottom were in very poor to poor conditions from the flooding .The growth and development of corn ranged from V18 to R2.  Very low leaf disease pressure. Disease observed included gray leaf spot, common rust, and holcus spot. The soybean crop was in poor to excellent condition, most soybeans in good-excellent condition. The soybean growth ranged beginning bloom (R1) to beginning pod (R3). Some bacterial blight was found in this region, but warmer weather will slow this disease down significantly.

Stop 11. corn

Stop 11 (NW Nora Hills): Rainfed corn-after-soybean tilled field with 26K ears per acre, 2k green snap in the R1 (silking) growth stage. I did see a northern corn rootworm, but I couldn’t get a picture of it…  Very health corn canopy.

 

Stop 12: Bean leaf beetles

Stop 12 (NW Nora Hills): Rainfed soybean-after-corn tilled field in full bloom (R1) in 30″ rows and not canopied yet. Bean leaf beetles one of the numerous insects causing minor defoliation.

 

Stop 13. Irrigated no-till soybeans-after-corn.

Stop 13 (NW Nora Hills). Irrigated no-till soybean-after-corn field that is nearly canopied and in the R2 to R3 growth stage. Very minor defoliation (<5%)  from bean leaf beetles and grasshopper species.

 

Stop 14. Corn

Stop 14 (NW Nora Hills). Rainfed no-till corn-after-corn looked great with 27k plants/ac at V18-VT growth stage on Belfore silty clay loam soil. Very healthy crop canopy. Holcus spot, a minor bacterial leaf disease shown in the picture here.

 

Stop 15: No-till irrigated corn-after-soybeans with 32k plants/ac.

Stop 15 (NW Nora Hills): No-till irrigated corn-after-soybeans with 32k plants/ac with 1K green snap. No insects observed and only common rust found in this field.

Thurman Dunes (north of Scribner)

The corn crop is showing more nitrogen deficiency this year than last year leading to reduce crop conditions, ranging from poor to good condition.  About 70% of the corn crop was pollinating, being delayed by nitrogen deficiency in a portion of fields. Around 4-6″ of rain fell with hail earlier that morning (Stop 17). The soybean crop was in fair to good condition with only minor leaf defoliation and very little disease pressure.

Stop 16: Irrigated soybeans-after-corn in 15" rows is canopied on this

Stop 16 (Thurman Dunes): Irrigated soybeans-after-corn in 15″ rows is canopied  and in full bloom (R2) on this Thurman loamy fine sand soil. This area received 4-6″ early that morning.

 

Stop 17: Corn-after-soybeans field had 28k plants/acre with some hail damage from the early morning storm event (July 18).

Stop 17 (Thurman Dunes): Rainfed corn-after-soybeans field had 28k plants/acre with some hail damage from the early morning storm event (July 18). Highly variable nitrogen deficiency symptoms across the field which is common for this area with Thurman-Leisy-Moody soil association.

Moody Hills (southeast of Uehling)

The corn crop ranged from fair to excellent condition. The growth and development of corn ranged from V18 to R2 (blister) as it has in other regions. About 70% of the crop was silking. Very low disease pressure and only common rust was observed. The soybean crop was in fair to excellent condition, most soybeans in good condition . The soybean growth and development ranged beginning (R1) to beginning pod (R3). An oat field looked to be in good condition and should be harvested soon (Stop 20).

Stop 18. No-till corn-after soybeans.

Stop 18 (Moody Hills). This rainfed no-till corn-after soybean field just received a lot of rain and some slight hail. The field had a good stand of 27k plants per acre was in the R1 (silking stage). Producers reported 6″ in his area west of Uehling.

 

Stop 19: No-till corn into rye cover crop.

Stop 19 (Moody Hills): Rainfed no-till corn into rye cover crop had a stand of 25K with 1K green snapped. Most of the rye residue has decomposed already.

 

Stop 20. Oats mature

Stop 20 (Moody Hills). Oats are mature and will be harvested soon. Given the shorter height of the oats, it may be the variety Horsepower.

 

Stop 21: Grasshoppers

Stop 21 (Moody Hills): Various grasshoppers species causing light defoliation. For more information on thresholds for spraying field borders and fields for grasshoppers, read this recent article from CropWatch: Scout Field Borders for Grasshoppers

Elkhorn River Valley (Scribner, Hooper, Winslow, & Nickerson)

The corn crop ranged from poor to excellent condition, most in good condition. The growth and development of corn ranged from V16 to R2 (blister stage). I did find gray leaf spot that was more progressed in a continuous corn field in this region. The soybean crop was in poor to excellent condition, most soybeans in good condition.

Stop 10: Soybeans after corn

Stop 10 (Elkhorn River): Irrigated soybean-after-corn tilled field was in the late full bloom to beginning pod stage growing on Coleridge silty clay loam.

 

Stop 22:

Stop 22 (Elkhorn River) : This irrigated soybean-after corn tilled field with well-drained Janude loam soils was at the R2 (full bloom), nearly R3 (beginning pod) growth stage and was also the tallest bean field during my tour. This field with 30″ rows was fully canopied.

 

Stop 23:

Stop 23 (Elkhorn River): Rainfed corn-after-corn tilled field at the V18-VT growth stage growing on Luton silty clay soil. This field looks better than it did in 2014 and 2015.

 

Stop 24: Gray leaf spot

Stop 24 (Elkhorn River): This irrigated corn-after corn tilled field was tone of two fields I found gray leaf spot in during the tour. Similar to some other fields this year, early seedling diseases from pythium reduced the plant population. There were 23k ears per acre and the corn was as the R2 (blister) stage. A representative ear had 18 rows by 41 kernels long. The soil in this area of the field was Coleridge silty clay loam.

End of regional reports

A reminder, 3 agronomic insights for the coming weeks:

  1. Scout soybean fields for defoliation (calibrate yourself on % defoliation, determine defoliation %, identify insect species) before spraying insecticides. Read more.
  2. Check your corn hybrid ratings for gray leaf spot resistance, talk with you seed dealer, and scout fields to better assess where a fungicide application will pay for itself.
  3. Determine crop water use and soil moisture status to help with irrigation scheduling.  View Dodge and Washington counties crop water use and soil moisture status reports.

View previous mid-July crop tours from July 14 and July 21, 2014 and July 16, 2015 

Dodge County Crop Tour – Mid July
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