Breeding corn isn't the first thing you think of when it comes to variety development at NDSU. The university is better known for producing durum, hard red spring wheat, oat and soybean varieties.

But NDSU has a corn breeder and an active program focused on finding early-maturity, drought-tolerant lines. NDSU hands off those lines to private companies to develop hybrids adapted to the state and other northern regions.

"NDSU's active corn breeding program, with 15 testing locations across the state, is essential to support the growth of corn production," says Marcelo Carena, NDSU's corn breeder.

More than 40 institutions (private and public) have requested corn products developed at NDSU, he says.

"Our corn breeding program is unique in that we have a winter nursery in Chile in order to have two corn growing seasons per year," Carena says. "Our location in Chile has the advantage that drought conditions can be controlled. We know there is no rain, so irrigation allows us to well manage our trials. The reason is that it is only possible to screen for drought tolerance in a location where you can manage the stress and it is not just the advantage of having an extra generation. The key to breeding for drought tolerance is to manage the stress. The objective of these experiments is not to simulate a farmer's field, but rather simulate a clearly defined stress that is relevant in farmers' fields. Therefore, if we use the western part of the state under random stresses, breeding progress for drought tolerance is not achieved. In Chile, we know of a place that is dry, never rains, and our cooperator is set up with an irrigation system that allows us to decide when to stop irrigating, collect data, select the best lines and hybrids, and test them in North Dakota the following summer."

Carena screens more than 2,500 inbreds and hybrids in Chile per year. Varieties that show promise are brought back to North Dakota for testing at sites across the state. Carena says the advantage of this system is that it speeds up the development process in an accurate and efficient way. Only one or two lines survive after three to five years of vigorous testing drought tolerance and agronomic performance, including grain yield and quality.

"Another unique feature of our testing efforts is the fact that our program is the most northern public breeding program," Carena says. "Our program is even north of the two Canadian corn breeding programs."

A great deal of Carena's work focuses on early maturing corn because of the state's climate. Early corn has similar genetic potential as late corn if you have an extensive and accurate program to identify it.

"For producers who want to sell their corn to a local ethanol plant, they need an early maturing hybrid with some level of drought tolerance, above-average quality and standability," Carena says. "Our corn breeding program is geared to meeting those needs so that corn production can remain sustainable in North Dakota. Our program is one of the unique programs testing corn hybrids in the western part of the state.

Data are collected for 31 traits, including disease resistance, maturity, stalk and root lodging, ear quality and seed set. Researchers also test for herbicide damage, drought and cold tolerance, and salt tolerance. NDSU researchers also conduct trials in Canada and Europe prior to releasing a line. The number of tests and the variety of locations increase the odds that an inbred line's weaknesses will be exposed before it is released. The inbred line is crossed by commercial and public testers to make hybrids. The hybrids then are analyzed at various locations for characteristics such as grain yield, moisture, lodging resistance, dropped ears, test weight, stand emergence, seedling vigor and grain quality.

"NDSU's corn breeding efforts are complementary to those of the industry in terms of drought tolerance," Carena says. "However, drought tolerance is a very complex trait controlled by many genes, the transgenic approaches used by the industry are limited to a few genes. If we work on most genes, then NDSU's drought tolerance efforts do not have any limit on genetic improvement."

Carena notes that the NDSU corn breeding program has been in existence for more than 75 years. Carena says continuity is essential for breeding programs to be successful. Carena is the third official breeder in the history of NDSU.

- NDSU Extension Communications