Drought tolerance a ‘hot’ topic for 2012 and 2013

In years to come, 2012 in Ontario will be remembered as a drought year along with 2001 and 1988. Despite the cheery prospect of a winter with little ground cover and uncommonly warm temperatures, many farmers spent the early part of the year bracing themselves for a drier-than-normal growing season. At the same time, several seed companies announced they were beginning to test drought-tolerant hybrids, with some commercial availability expected for the 2013 growing season.

For now, drought tolerance has not followed the gene implantation methods that brought Bt corn to market, although that work is underway. Instead, traditional breeding and assessments of various hybrids have followed a broader perspective, and always with the primary goal of improving yield. That’s why work has to proceed in a slow and orderly fashion — enhancing one trait can cause a corresponding loss in another aspect of the plant’s biology or its performance. A corn plant can grow to 12 feet high, with ears two feet long, but if a light breeze can cause lodging across the field, then improving height and cob size aren’t worth the effort.

Three stages are most affected by drought, including (in order of impact), flowering and pollination, grain fill and during the vegetative growth stage. Root health is one component that one seed company is focusing its efforts. Another company rates hybrid performance under varying moisture conditions, temperatures and soil types. The results of those tests indicate that a drought-tolerant hybrid does well with little moisture, yet doesn’t fare quite as well when moisture levels are normal.

Two other seed companies are also involved in drought-tolerant hybrid research; one is involved in the search for the “drought gene” — and is testing hybrids with that trait — while the other is looking specifically at the corn plant’s water-use efficiency and optimization capacity.

Each company is looking at a specific aspect of plant growth and performance, but across the board, they’re involved in a “total package” approach, where yield remains relatively stable while performance of the plant is improved across a wider array of conditions. It’s worth noting that under similar conditions in 1988 and 2001, corn plants would not have yielded as well as they likely will in 2012. Breeders and seed companies have advanced plant science by imparting a broader range of traits and characteristics on corn hybrids, enabling them to withstand more stresses than 11 or 24 years ago.

And it advances an approach voiced by Dr. Gary Ablett, renowned soybean breeder and former director of Ridgetown College of Agricultural Technology (now a campus of the University of Guelph). In the late-1990s, Ablett talked about the need for a “total package” in breeding.

Although drought stress is a problem in 2012 — and has been in parts of the U.S. since 2010 — the ideal is to find a hybrid that performs in all conditions, not just drought. It may sound repetitive, but performance across all conditions improves yield, and that is the sole determinant of success in breeding.

In other words, if it doesn’t yield, it doesn’t go to the field.

Look for the full version of this story in the upcoming November edition of  Country Guide East.

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