West-Central Forage Association

Evaluation of Thunder Seeds' low heat unit corn hybrids


Variety selection is an important part of production management because it affects yield, maturity and other agronomic characteristics which impact producer’s bottom line. Variety testing continues to be important in providing agricultural producers with information on newly registered and established seed varieties. To serve these producers, regional trials need to be conducted in the region to provide local producers and extension staff with reliable agronomic information.

To encourage producers to grow new seed varieties, it is necessary to showcase its advantage within the area. This trail aims to demonstrate Thunder Seed’s (TS) new corn varieties ability to establish in the west central region of Alberta, with the purpose of winter feeding cattle. In the 2015 growing season, three TS corn varieties TH4126, TH4574, and TH4578 were seeded along with Monsanto’s Hyland 2D093 variety, which was used as a control/check treatment.  Weather records, production and quality samples were collected and results will be available to producers to help them make management decisions.



  • To evaluate three different Thunder Seeds corn varieties for maturity, quality and yield
  • To compare these varieties against a control variety in the west central area of Alberta
  • Communicate information from the project to the producers of the areas covered by the association and beyond so they become familiar with the new varieties.



The demonstration plots were located at the West Central Forage Association Forage Research Site (SE 27-53-9- W5th) near Wildwood Alberta, which is located 120km west of Edmonton, in the gray wooded soil zone. In this soil zone the surface layer is leached of clay and plant nutrients. Soil and organic matter is low and crusting often reduces seedling emergence. Moisture is not as limiting as elsewhere in Alberta, but the growing season is shorter. Nitrogen is often the major limiting factor to high crop yields on gray wooded soils. The soil was tested for nutrients in the fall and this information was used to make fertilizer applications.

Plots were seeded in a prepared seedbed on June 10th, 2015 using a John Deere corn planter (20 m long 12 rows at 30 inch spacing) and GPS system, at a rate of 30,000 seeds per acre.  Glyphosate treatments were administered at 400ml/acre prior to seeding and when the crop was three leaf stage at 480ml/acre.

Once established, rows where trimmed 20 m for uniformity. At harvest, plant population counts and counts of mature and immature cobs were conducted along 17.5m length of 2 rows per treatment. Above ground plant matter was harvested, weighed and subsampled to determine moisture content, dry matter and feed quality by wet.

Weather data was collected from the (Alberta Agriculture) weather station in Evansburg, approximately 20 km from the research plot location, and used to determine Corn Heat Units (CHU) which are calculated using maximum and minimum growing season temperatures, and precipitation levels.



Stand establishment of corn was good, regardless the late seeding, and the lack of moisture.  Observation showed that the TH4126 variety grew taller than the other varieties, up to 10 inches taller (25.4 centimetres), measuring 35” at 44 days after planting (DAP). It is also noteworthy that this variety had a significantly wider leaf blade than the others, see Picture 1. Variety TH4574 was the second tallest at 28” (Picture 2), followed by TH4578 at 25’’ (Picture 3), and the check variety Hyland 2D093 at 24’ (Picture 4).


Picture 1. - TH4126 Treatment show 35 inches height and wider leaf that the other varieties at 44DAP


Picture 2. - TH4574 Treatment show 28 inches height, plot average 44DAP


Picture 3. - TH4578 Treatment shows 25 inches height on plot average 44DAP


Picture 4. – Hyland 2D093 Control treatment show 24 inches at 44DAP


Yields: Two samples were taken from each treatment to determine yield. The highest yielding variety was TH4126 with 7.5 tons and 6.5 tons per acre, followed by TH4574 with 7.0 tons and 5.8 tons per acre, the control treatment Hyland 2D093 with 5.3 tons and 3.8 tons per acre, and TH4578 had the lowest yield at just 2.4 tons and 2.3 tons per acre. Yield results are illustrated in Graphic 1 below.


Corn5Graphic 1. – Dry Yield matter for corn varieties grown in low (CHU) evaluation trail


Feed quality: The beef cow rule of thumb with protein is 7-9-11, which means an average mature beef cow requires a ration with crude protein of 7 per cent in mid pregnancy, 9 per cent in late pregnancy and 11 per cent after calving, (Yurchak, 2004).

The TH4126 and TH4578 varieties showed the highest of crude protein percentage at 11.71% and 11.6% respectively and TH4574 and Hyland 2D093 varieties showed the lowest at 10.96% and 9.71%. This can be seen in Graphic 2.


Graphic 2. - Crude protein percentage found in corn varieties grown inlow (CHU) evaluation trail at Wildwood Alberta.

Acid Detergent Fibre (ADF) is the fibrous, least-digestible portion of roughage.  An ADF content of less than 30% on DM basis is an indicator that the forage is high quality (Kopp, 2015). Neutral Detergent Fibre (NDF) gives a close estimate of fibre constituents of feedstuffs.  A low NDF level is desirable since the lower the NDF value the more of the forage cattle will potentially eat. High quality feedstuff should have less than 40% NDF value (Yaremcio, 2012). Total Digestible Nutrients (TDN) measures available energy of feeds and energy requirements. As a rule of thumb for a mature beef cow to maintain her body condition score (BCS) through the winter, the ration must have a TDN energy reading of 55 per cent in the mid pregnancy. (Yurchak, 2004).

Graphic 3 compares the feed quality of the four varieties grown. TH4574 was the variety with the lowest ADF with 26% ADF value followed by TH4578 and TH4126 with 33% each and the highest ADF value was Hyland 2D093 with 35% ADF value. TH4574 was the variety with the lowest NDF with 52% NDF value followed by TH4578 and TH4126 with 59% each and the highest ADF value was Hyland 2D093 with 60%. TH4574 was also the variety that show higher TDN with 68% TDN value followed by TH4578 and TH4126 with 63% each and the lowest TDN value was Hyland 2D093 with 62%.


Graphic 3. -  Corn varieties graph showing feed quality comparison between Thunders Seeds varieties TH4574, by TH4578, TH4126 and Monsanto variety Hyland 2D093 (control)

Net Energy Maintenance (NEm) is an estimate of the energy value of a feed used to keep an animal in energy equilibrium, neither gaining weight nor losing weight. A topical Alfalfa silage midbloom is 1.14 NEm Mcal/kg, Corn Grain is 2.24 NEm Mcal/kg, and Wheat straw is .64 NEm Mcal/kg. TH4574 variety showed the highest (NEm) with 1.70 NEm Mcal/kg followed by TH4578 and TH4126 with 1.55 NEm Mcal/kg for both varieties and the lowest was Hyland 2D093 with 1.50 NEm Mcal/kg value. The NEm values are seen in Graphic 4.


Graphic 4. – Energy (NE Mcal/kg) for all treatments in Wildwood Alberta

CHU: The corn heat units (CHU) is an energy term calculated for each day and accumulated from planting to the harvest date. CHU was calculated from May 1st to October 31st using data from the Evansburg weather station. Graphic 5 shows the historical data from the same weather station between 2012 and 2015 in 2013 show the highest CHU with 1730 CHU, following by 2015 with 2132 CHU on third place 2014 with 1777 CHU and the last place  was 2012 with 1730 CHU.


Graphic 5. - Historical CHU at the Evansburg weather station from 2012 to 2015

Precipitation: The annual total precipitation of the gray wooded soil zone from 1971 to 2000 was 500mm (Agroclimatic Atlas of Alberta, 2003). Graphic 6 shows the accumulative precipitation from the Evansburg weather station has been collected from 2012 to 2015 from May until October of each year.

Corn 10

Graphic 6. – Annual total precipitation in the Evansburg weather station from 2012 to 2015