Still shopping for top-performing seed corn? Then spend some time online checking out the 2017 hybrid trial results from Penn State University and the University of Maryland. Results from Penn State and Maryland should be available now online.

Cornell University silage hybrid results are expected to be available soon. Grain plots are still being harvested, so that data may not be available until January.

Commercial seed company data is already “out there.” The following links will make the Extension results easy for you to find. First, though, a few tips on what to look for.

6 biggest corn-picking pointers
Stacked insect and disease preventive genetic traits make comparing seed costs very difficult. Seed treatments add another layer to the challenge. You have to sort the value of those traits out after comparing yield differences.

Those yield differences can be substantial, says Penn State Extension agronomist Greg Roth. Performance differences of hybrids in the same maturities can range from 15 bushels per acre, “and frequently reach 50 bushels. As a result, improving corn yields by an average of 5 to 10 bushels per acre through careful attention to hybrid selection isn’t unrealistic,” he says.

• Yield: It’s essential to base performance information on several trial results, not just one. Average performance from numerous sites in your region is often a better indicator of future performance than results of one test — even on your own farm.

Also weigh moisture differences between hybrids when evaluating for yield. At a drying cost of $0.04 per point per bushel, and a corn price of $2.50 per bushel, every 1% moisture difference between two hybrids yielding 125 bushels per acres is worth 2 bushels per acre, Roth says.

• Prescribed potential: Plant breeders and hybrid testing programs have documented hybrid responses to high-yield and low-yield sites. There’s potential for selecting some hybrids for higher-yielding conditions and other hybrids for lower-yielding situations.

In Pennsylvania, one main cause of low yield potential is drought stress associated with shallow soils. So, a consideration of a hybrid’s yield stability may be important when selecting for such high- and low-yield situations. At this point, only limited data exists on the yield stability of available hybrids. But the seed industry is making an effort to characterize hybrids in this fashion.

• Maturity: It’s critical to choose hybrids that can use as much of the available growing season and still have a minimal risk of being frosted before maturity. Ranked by relative maturity, hybrids are assigned a days-to-maturity rating based on the grain moisture at harvest compared to other hybrids.

Keep in mind it’s a relative rating, not a measure of actual days to maturity. It’s not uncommon for a 105-day hybrid to require 150 days from planting date to reach maturity. One way to overcome hybrid RM differences between companies is to compare moisture contents of specific hybrids in performance trials where they appear together. Lower moisture content translates into an earlier rating.

The growing degree day system — calculated between planting date and black layer — is guided by weather heat units. But GDDs differ by location and season, and they don’t reflect dry-down after black layer.

A good rule of thumb is that corn for grain should reach maturity one to two weeks before the first killing frost in the fall, Roth says. Other factors, such as harvest method, marketing plans and timeliness considerations, may also bear on your maturity selection.

• Disease resistance: Resistant hybrids are the best control means for stalk rot, gray leaf spot, northern leaf spot and northern leaf blight.

Be wary of hybrids advertised as having “good disease resistance.” Ask your dealer about specific resistance to diseases you know are common on your farm.

• Standability: It’s especially important where corn harvest often continues into late fall. Considerable progress has been made in improving standability. But substantial hybrid differences still remain.

• Special considerations: We’ll cover only a few of a number of them. When evaluating silage hybrids, for instance, it’s best to base decisions on silage yield and quality data. Others include harvestability as ear corn, seedling vigor, test weight, tight husk cover for bird resistance, stay-green potential and grain or silage quality.

Negligible factors
The best hybrids in conventional tillage are usually the best in reduced tillage systems. One notable exception would be the need for higher gray leaf spot resistance where it’s a problem. But you might put emphasis on seedling vigor in early season no-till plantings.

Researchers have generally been unable to consistently document hybrid responses due to nitrogen form or timing.

A hybrid’s ability to "flex" its ears and produce a larger ear in response to lower populations and double-eared hybrids have been promoted as having the ability to produce better at lower populations. The idea behind it is that these hybrids could produce a larger ear in response to favorable conditions or reduced populations. However, studies in Iowa, Wisconsin and Ohio found that optimum populations don’t differ greatly among commercial hybrids. The best hybrids at low populations are generally the best at high populations, according to Roth.

Do your hybrid data homework
• Penn State’s 2017 Results: PA Commercial Grain and Silage Hybrid Corn Tests Report show grain hybrid results from 10 test locations within four growing zones. Silage results are from 11 test locations also in four growing zones. This year’s silage data now includes ash, fat (total fatty acids) and neutral detergent fiber digestibility — 30 hours, NDFD-120 hours, and NDFD-24 hours.

In-vitro starch digestibility data is or soon will be available from four locations. IVSD differs from starch percentage. The IVSD test is performed using wet chemistry, instead of near-infrared analysis.

• University of Maryland should have its 2017 version of Agronomy Report 54 on hybrid test plot data online at psla.umd.edu/extension/extension-project-pages/corn-maryland by now or very soon. The results from these replicated trials provide agronomic performance information about the corn hybrids tested at five Maryland locations.

• Cornell’s 2017 corn silage data should be available before year-end. Watch scs.cals.cornell.edu/extension-outreach/field-crop-production/variety-trials for results.

• Seed companies are also making local plot yield data easier and quicker to access. For Pioneer, you can check local yields summaries of each local plot by zip code. It includes competitive Pioneer-only comparisons, planting information and harvest results.