One size never fits all when it comes to matching corn hybrids with field conditions, pest control or timing. However, management differentiation is projected to intensify as the industry looks ahead to enhanced drought tolerance, enhanced nitrogen efficiency and hybrids modified for more fermentables, endosperm and other end-use traits.

"One of the most important decisions farmers can make is what hybrid genotype they select," said Fred Below, professor, plant physiology, University of Illinois. What complicates the process is that, as Below added, "Genotypes interact with virtually everything. They use nitrogen differently, they respond to population density differently, and they are more or less sensitive to weather conditions. And as the cost of seed has gone up and traits get added with up to three and soon to be four, people are expecting more out of their hybrids than in the past."

Not only are they expecting more and getting it, but also those expectations are driving management decisions. As more stress-free, optimum management conditions produce higher yields, incremental improvements of a few percent are easier to identify and justify, said Below. Higher yields of 225 to 250 bushels per acre are pulling out the old stops. It's something company agronomists like Bruce Battles, Syngenta Seeds agronomy marketing manager, wrestle with every day.

We do quite a bit of differentiation, identifying how we maximize production of each individual hybrid and is there something that needs to be managed differently," he said. He noted that as an integrated seed and crop protection company, he increasingly works with the other side of the business to identify productivity opportunities. One example is the synergistic hybrid response seen with foliar applications of Quilt fungicide. "We are seeing a response with no disease pressure present, and in some cases, even with hybrids with a high disease tolerance."

Battles explained that the synergy has shown itself through standability and late-season stalk quality improvements of as much as 20 percent. Late-season stalk quality is a growing concern as high yielding hybrids become more efficient at transferring end-of-season stalk nutrients into grain.

"Race horse type hybrids will do everything they can to fill an ear right to the tip. Others will slough off some kernels and potentially end the season with better stalks," said Dale Sorensen, corn systems lead, Monsanto. "A hybrid that is the best yielder early in harvest may not be the highest yielding hybrid 30 days later."

Sorensen advised going to the back side of the season when planning hybrid selection. He likes to look at each hybrid in a given geography and ask how many days does it take to harvest, start to finish. Select hybrids and manage harvest accordingly for maximum standability and yield.

What's Coming?
The next generation of traits may take yields to a new level through expanded pest control. Battles pointed to Syngenta's Agrisure Vitpera (awaiting regulatory approval and not currently sold) trait's that promise to reduce required refuges in the South. It also promises to control a complex of Lepidopteran pests that attack throughout the season. They include early season black cutworm, mid-season fall armyworm and late-season corn earworm or Western bean cutworm that previously received limited attention. Individually, these insects may have not reached treatment threshold or been recognized. With in-plant control, that will change.

"We are challenging growers to think about the complex of pests," said Battles. "If you put all these pest attacks together and think about them as one threshold, you can really maximize production versus thinking of them individually. We saw just under 11 bushel per acre yield advantage across all plots, but that grew to a 17.5 bushel advantage at multiple locations that had moderate to high levels of corn earworm pressure."

Another area where fine-tuning of hybrid management is expected to have a major impact is with drought tolerance and nitrogen utilization. Although Greg Luce, agronomy research manager, Pioneer Hi-Bred, said there are definite differences in current hybrids and where they fit.

Enhanced stress tolerance will open the door for higher populations. He pointed to improved stress tolerance in existing hybrids and greater tolerance predicted with future introductions. "We need to take advantage of that tolerance by planting optimum populations to get more ears and bushels per acre," he said.

"Nitrogen management practices, however, have not varied greatly, especially among hybrids of similar maturity," added Luce. "As we introduce new events with improved nitrogen use efficiency, there will be specific input recommendations by hybrid for nitrogen management."

Sorensen argued that nitrogen efficiency has already improved significantly with modern hybrids. He pointed to traditional university recommendations of 1 to 1.2 pounds of nitrogen per bushel of corn yield. That is changing, he said, as crop protection traits allow corn plants to develop and maintain larger root systems throughout the season.

"Illinois has shown that breeding and biotech improvements have already improved nitrogen utilization with corn hybrids now using closer to 0.8 to 0.85 pounds per bushel," he said. "As I look at new germplasm with biotech advancements, nutrient management recommendations will need to change. As we look at increased drought tolerance in the future, growers will have to change their management practices to get the greatest advantage and return from new hybrids and biotech traits."

Concerns over water quality impact as well as efficient use of a resource are also driving the issue of nitrogen management, suggested Keith Porter, agronomy services leader, Mycogen Seeds. "We are looking more broadly at how do we measure the nitrogen response and then apply that data to field production systems," he said. "There is a lot of talk about nitrogen efficiency in plants, but Dow AgroSciences has a solution today with nitrogen stabilizers. We are looking at specific responses by hybrids when used with stabilizers to measure the need for nitrogen within the growth cycle of the hybrid. As hybrids evolve and the product life cycles move even faster, it's an area where we need to gain a greater understanding and ensure growers are keeping nitrogen in the root zone when it is needed the most."

A Shift in Management Techniques
Porter predicts intensified management differences as hybrid development shifts to output traits. Once industry specifications are identified, management of hybrids can be fine tuned to produce to those specifications. He points to work Mycogen has done on influencing oil levels and quality in sunflower and canola, as well as development of dairy friendly forage corn hybrids.

"We have modified specific hybrids to produce 40 percent less lignin for higher digestibility and more dry matter intake for the cow," said Porter. "That translates into 4.8 pounds more milk per head per day over traditional corn silage. We think there will be more application of product knowledge to end uses of grain corn as we go forward."

Differential management by hybrid offers its own opportunities, noted Mike Kavanaugh, agronomy manager, AgriGold Seed. Timing nitrogen application by hybrid is one of several areas that AgriGold uses as a marketing differentiator along with the company's five genetic families, identified to customers as A, B, D, F and G.

"Early users, like our family A, perform best when given all their nitrogen up front," he explained. "Some, like our family G, maximize productivity with sidedressing. Some respond best to split applications. We also match plant populations and fungicides to our genetics to get the highest response."

Kavanaugh points out that some hybrids maximize yield at 36,000 to 38,000 but have a hard time competing at 28,000 to 30,000 while others max at 32,000, but lose root and stalk integrity at higher levels. He admitted that education and training is vital to the selling message.

"Everyone wants simplicity, but at the same time, all of them want maximum efficiency and maximum productivity. Our job is to help them sift through all the information. We have used the approach for years, and I think it is one reason customers stay loyal. It is one part of our agronomic solution."