Joe Lawrence, Allison Kerwin
The New York & Vermont Corn Silage Hybrid Evaluation Program continues to provide side by side evaluation of corn hybrids grown under a range of growing conditions representative of those experienced in the Northeast. In 2018 the program evaluated 77 hybrids from 17 different seed brands. Each hybrid was planted in replicated plots at 3 locations based on relative maturity (RM; Table 1).
The growing season was defined by below average precipitation and above average heat, measured as growing degree days (GDD) across trial locations (Figure 1). A defining difference between trial locations was the timing and amount of rainfall from late July to early September. While all locations realized some level of improvement in growing conditions with more frequent rainfall in late July and August, its timing and impact on the crop varied. In general, rain arrived at all locations in time to facilitate normal pollination of the crop but ear development varied by location.
The above average GDD accumulation throughout the season and particularly as the crop neared maturity resulted in fast dry down of the crop to target whole plant moisture content for silage harvest. A noticeable characteristic at harvest in many corn fields, including trial fields, was a healthy green plant with a dry ear.
While nutrient inputs at all locations met or exceeded crop needs, a lack of soil moisture may have compromised nutrient uptake at varying stages of crop development. Recognizing these real world influences and how a hybrid might perform under varying stressors is important to understand when evaluating this data.
The influence of growing conditions lead to location variability in hybrid performance in 2018 but overall better performance when compared to growing conditions experienced in 2017 (Figure 2).
The full report provides detailed data on individual hybrids entered into the program for 2018. The most significant parameters in the report vary by individual farm and that farms resources but some of the key data includes, yield, whole plant dry matter, starch content, measurements of fiber digestibility including neutral detergent fiber (NDF) digestibility at 30 hours (NDFD30) and undigested NDF at 240 hours (uNDF240), and predicted milk yields modeled in the Cornell Net Carbohydrate and Protein Synthesis (CNCPS) model. The CNCPS model predicts the expected milk yield of different hybrids based on their inclusion into a high corn silage total mixed ration representative of the diets fed on many NY and Northeast dairy farms.
It is important to evaluate this data in the context of your farm when selecting hybrids. The top performing hybrid at any one location or in any one category may not be a good fit for your feeding program. Factors that influence this vary by farm but include land base, soil resources, forage inventory, quality of available hay crops, access and cost of supplemental ingredients, and expectations of cow performance.
The trial results and location averages serve as a means to calibrate hybrid performance to a particular growing season and these averages can be used in conjunction with a company’s data on hybrids in their lineup, including hybrids not entered into these trials, to understand how a hybrid performed relative to what is realistic for that growing season. For example, in Figure 2 we see that over 50% of samples taken in 2018 had an uNDF240 value between 9 and 10 so this can be used to evaluate how close and far away from these values other hybrids performed in 2018. However, due to the challenging growing conditions experienced in 2017 and the impact of growing conditions on fiber digestibility we see that the highest percentage of samples in 2017 had a uNDF240 value of 13-14 while a very small percentage (less than 10%) of 2017 samples were as digestible as the majority of 2018 samples. Therefore it would not be fair to hold hybrid fiber digestibility or other performance indicators from 2017 to the same standards as 2018.
It is also important to recognize the companies that make these trials possible through their entry of hybrids. The following companies participated in the 2018 trials:
Albert Lea – Viking, Augusta Seed, Channel, CROPLAN, Dairyland, Dekalb, Doebler’s, Dyna-Gro, Growmark FS, Hubner, Local Seed Company, Masters Choice, Mycogen, Pioneer, Seedway, Syngenta – NK, Wolf River Valley
The full report of 2018 can be found at the Cornell Soil and Crop Sciences website:
https://scs.cals.cornell.edu/extension-outreach/field-crop-production/variety-trials/#corn-silage
Additional trial information can be found in the following article and webinar:
Article: 2018 Corn Silage Overview
https://prodairy.cals.cornell.edu/production-management/resources/
Webinar: 2018 Corn Silage Hybrid Test Results, New York and Vermont Corn Silage Hybrid Tests – 2018
https://prodairy.cals.cornell.edu/webinars/
