Corn: Yield and forage (silage) quality have been increasing for about 100 years, with a “great leap forward” in the 1930s with the advent of corn hybridization. There have been dips (most recently in 2012) but the upward yield trend continues. Forage quality increased due to genetic advances (mostly a higher ear: stalk ratio), improved fertilizer use and overall better crop management. The first sales of BMR hybrids almost a generation ago resulted in much higher fiber digestibility but at the expense of yield. While opinions differ, it appears that the “yield drag” between BMR and conventional hybrids isn’t narrowing by much. Comparisons are tough to pin down since Northern Corn Leaf Blight ravaged some of the BMR hybrids in recent university trials, affecting both yield and quality. BMR has a significant quality advantage but there’s simply not enough reliable data to say whether the quality difference (primarily NDF-d) between BMR and conventional hybrids is narrowing. The decision by Cornell University not to run its statewide corn silage hybrid trials in 2014 due to shortages of labor and equipment will make this type of information even harder to find.
Alfalfa: Improved varieties of alfalfa were released in the mid 1900s, with the focus on better disease control and insect resistance. However, these are only helpful if the disease or insect is present, and in many cases it is not. Research done several years ago came up with this depressing conclusion: “Nutritive value traits were similar among cultivars released between 1940 through 1995 (which was the last year included in the study). Results of this research demonstrated that plant enhancement procedures used to produce improved alfalfa cultivars over the past 60 years had no effect on forage yield in alfalfa.” More recently there have been renewed efforts to improve alfalfa quality, but so far this has been at the expense of yield. According to Julie Hansen, Cornell University plant breeder, “In general selecting for improved forage quality tends to result in populations with lower yields.” Cornell’s 2013 forage trial summary confirms this: N-R-Gee, Cornell’s alfalfa variety selected for higher digestibility, resided at or near the bottom of several yield trials.
Note: Readers may be confused by the use of the terms “cultivar” and “variety” when referring to alfalfa and other plant species. These terms are often used interchangeably (including by the Crop Dude) but they’re different. Cultivar is a term coined by Liberty Hyde Bailey, who founded the College of Agriculture at Cornell University. A cultivar is short for “cultivated variety” “culti” + “var” and is intentionally bred, while a variety evolved or developed without any human influence. Old Liberty Hyde was a clever fellow.
Grass: Most of the excitement in cool season forage grasses has been in grass species rather than in varieties within a species. Reed canarygrass got a lot of excitement 30 years ago with the advent of low alkaloid varieties. But since Palaton was first marketed there hasn’t been any new variety showing enough improvement to get excited about. (Cornell didn’t include any canarygrass varieties in its 2013 forage variety trials report.) Not much news for orchardgrass: In an orchardgrass variety trial seeded by Cornell in 2010, in 2013 the top-yielding variety was the check variety Potomac which was released 60 years ago, in 1954! Tall fescue is now considered by many to be one of the best forage grasses now that endophyte-free varieties are widely available, but according to recent data the newest varieties aren’t much better than older ones for either yield or quality. There are significant differences between tall fescue varieties, though, and you’d be well advised to choose one of the higher yielding ones, especially for straight or mostly grass seedings. Here is a link to recent Northern NY data (your tax dollars at work).
Source: William H. Miner Agricultural Research Institute