Archive for October 2015
A few weeks ago, we visited some millet farmers in the Sitapur Dt. of Uttar Pradesh. We came across a barnyard millet (साँव़ा) field in Aanth (आँट) where the plants had fallen due to a combination of too much water and wind. Strong vegetative growth of these plants to more than 7′ had raised the family’s hopes of being able to get a bumper harvest. It was more than a week since the incident and they had resigned to their fate that the grains that were still in the filling stage would now rot.
Wheat is the main crop in this region. A fallen wheat plant leads to reduced harvest due to various reasons. Coming from this experience the fallen Barnyard crop was also interpreted as a slash on the quantity and quality of the harvest.
But as I suspected, what we saw in the field was a totally different story. There are two things that almost all millet plants do when they fall. One : they push in new roots from their nodes that are close to the ground. And two: they start growing their apex, and hence the panicle, back to a vertical position. These are two of the many amazing things that makes millets special. A weak stalk and insufficiently developed root system cannot fill the grains in the panicles. So an adverse condition (strong winds) leading to a compromised state (having fallen down) appears to be turned into an advantage by exploiting the proximity to the ground to push in new roots and revitalize the plant ! A self correcting system, eh? 🙂
In pursuit of food security and sovereignty, we traded such hardy crops for such sensitive and input / care intensity crops like wheat and paddy!
The portion of a plant that connects the shoot to the root is commonly referred to as the collar region. An amazing thing can be noticed in most millets.
As the plant grows, the younger tillers push the older tillers further and further away from the central axis of the plant. At each node in their older tillers, new tillers branch out growing skyward. The parent tiller becomes more and more horizontal and its secondary tillers weigh it down further and further bringing it almost parallel to the ground. From each of the older nodes within these tillers, we see secondary roots being pushed into the ground to bring in the good stuff to grow the plant. Essentially, the older nodes in the senior tillers become a secondary collars !
I have seen this in Barnyard, Proso and Browntop millets and given their taxonomy I would expect that Foxtail, Little millets would have a similar behaviour too. While, I suspect that Kodo and Finger millets would be exceptions to this characteristic, I would be more than glad if I am proven wrong !
Millets are amazing. Most people would have seen sorghum and pearl millet in the fields growing to more than 8′ in height, and among traditional varieties, 10′ is totally the norm. Some might have noticed how these amazing plants put secondary roots from their collar nodes to support themselves as they grow.
On reaching reproductive stage, the grain filled panicle at the apex of the plant can easily weigh about 300 gms. So, one can approximate the plant to a cylinder with about 2″ to 3″ diameter and a height of 120″, held at one end, with a 300 gm weight at the free end. So its not really surprising that purely from a physical dynamics perspective they put down secondary roots from not just one, or two but even three nodes as seen in this image below. I am sure I am not alone in seeing the many beautiful math and physics concepts that one can explain, demonstrate and possible experiment with in this amazing natural wonder.
And then there is the physiology of the structures. More on that in a later post.