Hi there! My name is Rachel Veenstra and I am a PhD student working with Dr. Ignacio Ciampitti in the Agronomy Department at Kansas State University. Check out this video abstract to learn more about our latest journal and Extension publications on yield responses to tillering in dent corn!
Tillering in corn is a topic that has always been a source of debate.
Breeders' selection of single-stalked, uniform plants has increased the plant density needed to reach maximum yields over time. Not all production systems support these high population densities, and tillering potential is still present in modern commercial corn hybrids. Tillers are expressed when key environmental conditions are present (such as adequate water, good fertility, abundant sunlight, and cooler temperatures).
Research on the impact of tillers in these low densities is outdated and generally unavailable.
We wanted to understand 3 things in this current study:
The relative importance of plant density, tiller presence, and environment to final yields for two commercial corn hybrids
The impact of tiller density, plant density, and their combined number on yields
The environmental factors that likely determine how yields respond to tillers in modern hybrids
This is how we did it.
With 11 different field trials set up across the state of Kansas in 2 different years, we tested the impact of:
3 plant densities (10,000, 17,000, and 24,000 plants per acre – which equates to 25,000, 42,000, and 60,000 plants per hectare),
2 hybrids (Corteva Agriscience – Pioneer P0657AM and P0805AM), and
2 tillering scenarios – one with tillers intact and the other with all tillers removed at the main plant tenth leaf stage (V10).
For a more detailed description of how we set up our field trials, check out this post! https://rveenstra.wixsite.com/tillers/post/the-lowdown-on-our-low-densities
Figure taken from https://bookstore.ksre.ksu.edu/pubs/MF3571.pdf
We had three major findings from this study.
Tiller presence never reduced yields in any of our site years, at any plant density, or in either hybrid.
Yields responded differently to tillering when comparing locations, but an adjustment to plant density was needed to maximize yield potential in all cases. Tillers had plant density compensation potential, but could only boost yields so far.
Sites with yields that increased the most when tillers were present had two key environmental characteristics.
First, good soil quality – high OM, for example.
Second, higher photothermal quotient values – which means the crop experienced cooler temperatures and greater solar radiation, increasing energy availability during early vegetative stages.
For more information on what the photothermal quotient is, check out the graphic in our Extension publication! https://bookstore.ksre.ksu.edu/pubs/MF3571.pdf
The key conclusion from this study is that tillers have potential as a corn plasticity trait.
This plasticity means that they can be useful to the plant as it works to adapt to its environment – in our case, particularly if the planted density ends up being too low or if stands are damaged or reduced unexpectedly.
I invite you to read our new K-State Extension publication or our paper in Crop Science to learn more! Thanks for supporting our research, and you’ll be hearing from me again soon!
This research was made possible by funding from Corteva Agriscience, the Kansas Corn Commission, the Kansas State University College of Agriculture, and K-State Research and Extension!