Ontario Grain Farmer November 2021

24 In the hybrid testing side of the program, corn companies can access material from genetic suppliers from around the world and/or from their own breeding programs. Breeders take products of interest and then test them in small plots across a few locations while they get comfortable with the genetics. “Hybrids are recommended for a targeted environment based on previous experience with related lines, it’s very rarely a truly unknown situation,” notes Winter. Once a breeder is comfortable with how the hybrid behaves, they will increase the number of trial locations to further test the yield and agronomic stability of the hybrid. This level of assessment will occur for two to four years at multiple sites. If everything still looks promising, it will then be placed in pre- commercial strip trials; and if it passes through all of the company’s objectives, would then be commercialized. In this system, the breeder and production team will have experience with the hybrid for three to four years before a farmer would be able to purchase it for their farm. When screening for disease tolerance, Winter explains they work closely with Albert Tenuta, field crop pathologist with the Ontario Ministry of Agriculture, Food and Rural Affairs, and participate in disease screening trials. For some trials they rely on natural infection which can be difficult in some years when weather patterns do not cooperate. A significant effort also goes into looking at DON in corn, a troublesome disease for Ontario corn. Winter and his team are aiming to mimic what farmers see in fields, as opposed to an inoculation nursery system which is the standard method of testing currently. Seed development: corn BREEDING NEW LINES, TESTING NEW HYBRID CROSSES Laura Ferrier Research Ontario has such a diverse, variable climate, “it’s all a balance,” says Winter, “of having the right number of locations in the right maturity areas.” Through experience, breeders learn the locations that have high or low yields, which areas behave similarly, or vise versa. They also look for areas of uniqueness, with the hope they will find varieties that do well in drought, or be able to target areas that have specific insect or disease pressure. Another area they look at is different field management strategies such as high and low populations, how fungicide applications impact the hybrid, high nitrogen rates, and crop rotations. “Whether it is corn, soybeans, or any other crop, breeders are all trying to do the same thing, get the most data for the hybrid/variety that they are working on to be able to recommend positioning in the right place for the farmer’s success in their field,” says Winter. Once a hybrid has received the gold stamp of approval from a breeder or company, it will then be placed into commercial hybrid corn production. COMMERCIALIZATION Commercial production of hybrid corn begins with a small amount of inbred seed being delivered from the breeding program, where the seed will be increased for larger commercial production. Most companies will do their base seed production in unique locations, often the Pacific Northwest, where there is low corn production to avoid any corn pollen from other fields contaminating the inbred increase. Seed from these increases are then delivered to the production facility. “Many production and handling facilities are in the Chatham-Kent area for corn hybrids in Canada,” says Harwood. FARMERS KNOW WHAT is going on in their fields during the growing season, but are we all aware of what goes on prior to the seed arriving in our sheds? This article is the first in a series that will explore the process of seed development. Shawn Winter, product development manager with Maizex Seeds Inc, explains corn breeding and what it takes to get a corn hybrid commercialized. Dave Harwood, technical services manager with Corteva Agrisciences, describes the process after a successful hybrid has been created, until that corn seed ends up in your shed. There are commonly two sides to a corn breeding program, breeding new lines, and testing new hybrid crosses. The breeding side of the program is where the corn breeder creates populations using known inbreds that work well in each maturity zone. With these populations they select for phenotypic and agronomic traits that would be beneficial in the hybrid. New inbreds are placed in small trials with one or two repetitions in several locations where they will screen out the worst inbreds. The preferred inbreds will then be crossed with known inbred lines to create hybrid combinations and are then tested to see if they produce successful crosses. Once the breeder has taken a couple of years to assess how successful the combinations are, the inbred crosses then enter the hybrid testing network.