Madison, WI, March 16, 2009 -- One of the most significant developments in agricultural growth in modern times has been the continuous and substantial increase in corn yield over the past 80 years in the U.S. Corn Belt.
This extraordinary yield advance has been associated with both breeding of improved hybrids and the ability to grow them at increased density. In a new study, published in the January-February issue of Crop Science, researchers have investigated the importance of the effects of leaves and roots on this dramatic increase in yield in the U.S. Corn Belt, and have found that the root structure may be the key to understanding how these crops have grown so efficient.
One associated change in the traits of these corn crops has been a more erect leaf angle, which is known to create greater efficiency in converting incident light to biomass. Over the years, detailed studies have shown that the increase in total biomass accumulated through sustained photosynthesis is one of the key factors explaining the yield increase.
However, some studies have also shown that changes in the root system also have an effect, as newer hybrids appear more effective at extracting soil water from deep in the soil profile. There is some evidence suggesting that hybrids with narrower root angle have this capability. It is also plausible that decrease in root angle combined with growing plants at higher density could cause the increase in biomass accumulation. Root systems with improved occupancy of the soil at depth can extract more water to sustain biomass increase.
A team of scientists from Australia and the U.S.A., led by Professor Graeme Hammer of The University of Queensland (UQ), conducted this study on the leaves and roots of corn as part of an Australian Research Council linkage project with Pioneer Hi-Bred International. The project included scientists from UQ, Queensland Department of Primary Industries, and Pioneer.
|Contact: Sara Uttech|
Crop Science Society of America