ALONG the V4 roads of the some of the oldest sectors of the Chandigarh (Sector 18, 19, 27, 28, 29 along with the southern sectors) are lines of a tree called Karanja. Also known as the Indian Beech tree and Poonga oil plant, the tree comes from the Western Ghats and is cultivated as a shade tree.
Now, if you drive past them these days, you’ll notice its leaves, pockmarked with spots, almost like “paan” (beetlenut) stains on the shiny green surface, like an easel with random paint blots on it.
The blemished dramatics aside, while we assumed the spots were the reason the tree gets its nickname “Papri”, city horticulturists snapped us out of our stupor, and shared how the marvelous tree was being tainted by the nasty leaf miner. A leaf miner, for the uninitiated, is the larva of an insect that lives in and eats the leaf tissue of plants. It can be moths, sawflies, flies, even some beetles that indulge in this vicious attack. The hot and humid weather makes it even more comfortable and conducive for this pest to thrive.
According to horticulturists, the UT administration should be spraying the required pesticides and insecticides at scheduled intervals to control the rapid spread of this attack for the numbers have increased due to the depletion of forest areas around the city, from where the pests fly in, looking for more host trees. While it doesn’t do much damage to older trees — they develop some resistance — it sure does mar their beauty and weaken the spirit. Especially of something as magnificent as the Pongamia pinnata (Pongamia Glabra, of the family Papilionaceae).
Why? Well, because this fast growing deciduous tree, that also showers white, purple, pink blossoms in May-July, can produce sustainable biofuel crop, inedible oil (bio-diesel, starch, ethenol) and biogas (by fermenting the present seed cakes). Flowers of India also mentions how using Papri or Honge oil, some villages in India have created their own power grid systems to run water pumps! Not only is it drought resistant, it’s a nitrogen fixing leguminous tree making it pretty good for the soil.
A lot of research has shown the importance this tree’s oil — a thick yellow orange to brown coloured oil extracted from the seed. In India, it’s added, that it can be used as a fuel for cooking and lamps, and as lubricants, pesticide and in soap making industries. The crude oil for analysis is collected from Indian Biodiesel Corporation, Baramati and Maharashtra, India. The Karanja leaves, on the other hand, have medicinal properties and used as anthelmintic, digestive, and laxative, for inflammations, piles and wounds.
On the downside, a recent news report from Hyderabad, where Karanja has been planted on thousands of hectares, is yet to show results as a bio-diesel resource for it needs a good supply of water for producing seeds. While the research is still on, the immediate concern here is to control the leaf miner from attacking this wonderful tree.