TILLERS IN CORN : What does the plant wants to tell us?

Grain Corn
Silage Corn
Western Canada

The world of grass plants

Tillering is a common phenomenon in grasses. Several cereals such as wheat and barley for example benefit from this and this is particularly true in winter cereals where each additional tiller produces a generally harvestable spike head.

Although beneficial for maximizing grain yield, corn is also a grass that can sometimes produce tillers. For several years, efforts in terms of genetic selection of corn have aimed to produce hybrids that can support higher populations to maximize yield potential. The development of tillering is reduced, but we can still sometimes observe it in our fields.    

Why and possible causes?

Optimizing corn yield involves maximizing kernels on the same ear rather than the number of ears on the same plant. Tillers are basically branches that grow from buds at the lower five to seven nodes of a corn plant's stem. We often see their appearance around the 4 to 7 leaf stage.

The number of tillers that develop is determined by plant population and spacing, soil fertility, early season growing conditions, and the genetic makeup of the hybrid. We usually see the phenomenon of tillering in corn at the end of a field or in more sparse areas.

No effect on yield

It has long been thought that tillers draw water and nutrients away from the main stem and therefore decrease overall yield. However, research has shown that tillers have no negative effect on yield. It could even slightly increase the dry matter produced for corn silage, and even serve as a source of nutrients for the main ear in the event of difficult growing conditions.

Team work  

There is very little photosynthesis movement between the main stem and the tillers before before tasseling. However, after silking and during grain filling, plant sugars can move from headless tillers to main stem heads. When there are spikes on both the tiller and the main stem, very little movement of plant sugars occurs. Main stem and tillers act independently and each receives sugars from its own leaves.

Seize the message of the plant and remedy it

When walking a field with adequate population and observing a tiller here and there, there is therefore no cause for concern. On the contrary, we can understand that our corn lacks neither water nor nutrients and allows itself the luxury of tillering.

However, excessive tillering (more than two or three tillers per plant) may indicate that corn plants are maximizing their development because conditions permit. This allows us to think that our hybrid could tolerate an even higher population, which would have the effect of increasing the yield. These observations will make it possible to correct the situation next year!