Drought-Tolerant Hybrid Technology Ramping Up
Drought-tolerant hybrids have come a long way since Wayne Fithian started working with ecofallow, dry land crop production at Colorado State University (CSU) in the early 1980s and with Golden Harvest later. With new technologies in native gene selection, not to mention transgenic gene introduction, dry land corn is poised for even greater advances. Ironically, what Fithian and his CSU colleagues were searching for with arid conditions may prove to be equally valuable in a Midwest dealing with climate change.
"Some of the defensive mechanisms that plants employ to address drought stress are similar to mechanisms to prevent damage from heat or cold stress," said Fithian, product lead, Technical Traits, Syngenta. "In many cases, genes have a broad-based stress response. In others, genes have a more narrow response."
Finding the right response through traditional breeding was literally trial and error through the early 2000s, noted Fithian. He compares it to improving the odds from 1 in 20 to 1 in 15. Even when successful, it was difficult to identify a specific improvement at a specific growth stage. Sometimes these were whole plant characteristics. Sometimes a single characteristic, such as an ear height that ensured a combine snout could get under the ear on a drought-stressed stalk, were selected.
"While we always had a hybrid or two to depend on, we also had to use relative maturity to bolster yield potential under drought," recalled Fithian. "As we approached the late 1990s and early 2000s, drought tolerance had improved across the industry such that growers had more options in hybrids and relative maturities. Now, access to drought-modified hybrids is producing another jump in options and yield potential."
MULTIPLE TECHNIQUES COMBAT DROUGHT
Many of the new hybrids are the result of a combination of traditional breeding techniques and gene marker assisted selections. Others are more refined, traditional approaches. One thing that is uniform across the industry is recognition that drought tolerance, while desirable, cannot detract from yield potential under optimal conditions.
Mapping of the corn genotype and the identification of DNA markers opened the door to the gene marker approach. At Syngenta, this led to the introduction of Agrisure Artesian hybrids. DuPont Pioneer used its Accelerated Yield Technology (AYT) to develop and introduce Optimum AQUAmax hybrids. Using the gene marker approach, specific areas in the genome or specific genes are identified that correlate to drought/stress tolerance.