Tag Archives: corn

Tamra Jackson-Ziems, NE Extension Plant Pathologist

Bacterial Leaf Streak
Grower reports and samples submitted to the Plant and Pest Diagnostic Clinic indicate bacterial leaf streak is increasing in corn. This week it was confirmed in Box Butte, Scotts Bluff, and Kimball counties and has now been confirmed in 70 counties. A survey is underway to collect samples from western Nebraska counties where it hasn’t been confirmed.

Southern Rust
Southern rust was confirmed in three more counties this week: Phelps, Howard, and Otoe, making a total of 12 counties in eastern Nebraska where it’s been found. To follow movement of Southern rust in Nebraska and other states, view the map at http://ext.ipipe.org/

Given the economics of a fungicide application and low corn prices, an application is generally not recommended at this point in the season unless there is a major flare-up in a given field, or if the field was planted very late and is earlier in development and more vulnerable to disease.

Gray leaf spot is also being reported in corn.

Frogeye Leaf Spot
Reports of phytophthora and Frogeye leaf spot continue in soybean. If you apply a fungicide for control of Frogeye leaf spot and do not get the control you expect and suspect resistance to fungicides, please send samples to the university’s Plant and Pest Diagnostic Clinic and indicate the sample is for Frogeye research. Please indicate the fungicide applied, application rate, and date applied. Fungicide resistance has been documented in the Bootheel of Missouri and in eastern Iowa.

For more information on individual diseases of corn and soybean, see Plant Disease Management for Agricultural Crops in CropWatch… https://cropwatch.unl.edu/plantdisease.

NEBRASKA:  Based on August 1 conditions, Nebraska’s 2018 corn production is forecast at 1.83 billion bushels, up 9 percent from last year’s production, according to the USDA’s National Agricultural Statistics Service. Acreage harvested for grain is estimated at 9.35 million acres, up 1 percent from a year ago. Average yield is forecast at 196 bushels per acre, up 15 bushels from last year. Both yield and production are new record highs if realized.

Soybean production in Nebraska is forecast at 332 million bushels, up 2 percent from last year, and a new record high if realized. Area for harvest, at 5.45 million acres, is down 4 percent from 2017. Yield is forecast at 61 bushels per acre, up 4 bushels from last year, and a record high if realized.

Nebraska’s 2018 winter wheat crop is forecast at 48.0 million bushels, up 2 percent from last year. Harvested area for grain, at 1.00 million acres, is down 2 percent from last year and a new record low if realized. Average yield is forecast at 48 bushels per acre, up 2 bushels per acre from 2017.

Sorghum production of 15.8 million bushels, is up 32 percent from a year ago. Area for grain harvest, at 155,000 acres, is up 15 percent from last year. Yield is forecast at 102 bushels per acre, up 13 bushels from last year, and a record high if realized.

Oat production is forecast at 2.43 million bushels, up 42 percent from last year. Harvested area for grain, at 45,000 acres, is up 10,000 acres from last year. Yield is forecast at 54 bushels per acre, up 5 bushels from 2017.

Dry edible bean production is forecast at 2.96 million hundredweight, down 24 percent from last year. The average yield is forecast at 2,410 pounds per acre, down 110 pounds from last year. Acres planted by class are as follows: Pinto, 61,800; Great Northern, 41,800; Light Red Kidney, 8,800; Chickpeas, 12,000.

Sugarbeet production is forecast at 1.51 million tons, up 5 percent from 2017. Area for harvest, at 45,500 acres is down 600 acres from last year. Yield is estimated at 33.9 tons per acre, up 2.1 tons from a year ago, and a new record high if realized.

Alfalfa hay production is forecast at 3.78 million tons, up 15 percent from last year. Expected yield, at 4.30 tons per acre, is up 0.35 ton from last year, and a new record high if realized. All other hay production is forecast at 3.33 million tons, up 16 percent from last year. Forecasted yield, at 1.80 tons per acre, is up 0.2 ton from last year. Both yield and production for all other hay are new record highs if realized.

 

KANSAS:  Based on August 1 conditions, Kansas’s 2018 corn production is forecast at 658 million bushels, 4 percent below last year’s production, according to the USDA’s National Agricultural Statistics Service. Area to be harvested for grain, at 5.10 million acres, is down 2 percent from a year ago. Yield is forecast at 129 bushels per acre, down 3 bushels from last year.

Sorghum for grain production in Kansas is forecast at 231 million bushels, up 15 percent from last year. Area for harvest, at 2.65 million acres, is up 8 percent from 2017. Yield is forecast at 87 bushels per acre, up 5 bushels from last year.

Kansas’s soybean production is forecast at 173 million bushels, down 8 percent from last year. Area for harvest, at 4.81 million acres, is 6 percent below 2017. Yield is forecast at 36 bushels per acre, down 1 bushel from last year.

Winter wheat production is forecast at 277 million bushels, down 17 percent from last year’s crop. Area for grain, at 7.30 million acres, is up 5 percent from last year. Yield is forecast at 38 bushels per acre, 10 bushels below last year.

Cotton production is forecast at 250,000 bales, up 27 percent from last year, and a new record high if realized. Acreage for harvest, at 116,000 acres, is up 26,000 acres from 2017, and a new record high. Yield is forecasted at 1,034 pounds per acre, down 17 pounds from last year.

Oat production is forecast to be 2.40 million bushels, up 78 percent from last year. Harvested area for grain of 50,000 acres is up 25,000 acres from a year earlier. Yield per acre, at 48 bushels, is down 6 bushels from a year ago.

Potato production is forecast to be 1.36 million hundredweight, down 13 percent from last year. Yield of 400 hundredweight per acre is 20 hundredweight above 2017 and is a record high if realized.

Alfalfa hay production of 1.52 million tons is forecast to be 26 percent below last year. Expected yield, at 3.10 tons per acre, is down 0.5 ton from last year. All other hay production of 3.20 million tons is forecast to be down 20 percent from a year ago. Expected yield, at 1.60 tons per acre, is down 0.3 ton from last year.

 

Corn struggling in drought-stressed growing areas this season, may be a good option for cattle feed–providing at least some salvage value for affected acres. There are, however, a few cautionary notes.

Kansas State University beef systems specialist, Jaymelynn Farney, says silage is likely the best choice, but notes there are other considerations.

“Drought-stressed corn silage or baleage is often higher in protein than conventional corn silage, even though energy values are generally lower,” she notes. “Additionally, drought-stressed corn silage has less lignin than conventional silages.”

She says if property ensiled, nitrate concentration on drought-stressed corn will be reduced 30% to 60% after the ensiling process. Optimal moisture content for proper ensiling depends on storage method. Silage stored in a bunker, for example, should be harvested at 65% to 70% moisture; baleage can be 45% to 60% moisture.

“Putting up drought-stressed corn for hay,” she adds, “is the least recommended because even when we think it is very dry, it’s large stem generally isn’t. If putting up for hay, condition the stem to aid in drying.”

Farney points to a 2012 North Dakota State University study where corn was cut for hay and had to cure for 30 days to reach 16.2% moisture. Also nitrates are not reduced in hay, like they are during the ensiling process.

Another option to use drought-stressed corn would be in-field grazing. This would minimize nutrient removal from the field. Be aware there is potential for nitrate toxicity and acidosis. Nitrate toxicity potential is reduced if cattle don’t eat the stem and lower 8 inches. Acidosis can be a concern, depending on how much mature grain is in the field.

“To minimize issues with acidosis, strip graze and allow the cows only a couple of days in each strip,” she recommends. “Calf gains while grazing standing corn have been reported between 1.6 and 3.3 pounds per day.”

The energy value of drought-damaged silage can range from 75% to 95% that of regular silages. Farney says it’s important to test silage for nutrient content to help balance the ration. Limit feeding is best for this, as cows will voluntarily consume 2.5% of body weight on a dry matter basis of corn silage.

Corn is already in reproductive stages in many parts of the state, particularly in eastern Kansas. One of the main challenges presented in the last month, besides the lack of precipitation, was the high night temperatures.

Nighttime temperatures started increasing as June progressed.  During the first half of the month, for even the warmest locations, lows were greater than 70 degrees F only half of the time.  However, during the last part of June and the beginning of July (June 16- July 5), the total number of days with temperatures above 70 degrees F increased in the eastern part of the state to almost three-quarters of the time in the warmest regions (Figure 1).

Figure 1. Total days with minimum temperatures greater than 70 degrees F for the period June 1 – June 15 (upper panel) and June 16 – July 5 (lower panel). Map by the K-State Weather Data Library.

High nighttime temperatures during the reproductive growth (at or after flowering) can reduce kernel number, and if later in the season, kernel weight. This effect can be explained as an increase in the rate of respiration, increasing the demand for sugar for energy and diminishing its availability for supplying the growing kernels.

In addition, as experienced in many parts of our state, high night temperatures tend to accelerate plant phenology, running more quickly but with overall lower plant efficiency in using available resources. This situation has been documented in many parts of the state as an earlier-than-usual (close to 2 weeks) flowering time. For example, a corn planted during the first week of May was flowering around the first or second week of July in 2017 (depending on the maturity) and a similar corn hybrid this year was reaching the same stage around the last week of June.

The effect of high night temperatures will be exacerbated as corn is entering into the most critical growth period (a few days before flowering to grain filling). The consequence of high night temperatures will be reflected in reductions in kernel number (if timing of the stress was around flowering) and/or kernel weight (if timing of stress was coincided with the grain filling period).

In summary, high night temperatures will be impacting corn yields primarily in the eastern part of the state, but the final yield reduction is yet to be determined, clearly depending on the timing of the stress (duration) and the area of the state affected.

Scout your corn fields and stay tuned for more information in upcoming eUpdate issues!