New invasive weed spotted in Karnataka

Plant scientists have sounded an alarm over a new weed that has been spotted in parts of Karnataka. 

The plant, identified as Ethulia gracilis Delile, is growing wildly as a weed in several places of Belagavi district of Karnataka and may have come from Africa. It was first collected near Nipani- Chikodi road in the late monsoon of 2017. During subsequent visits, researchers spotted it in Mahalingpur, Mudhol and Jamkhandi Taluks of Bagalkot district also. 

“There are good chances of this weed spreading to other parts of the country like other noxious weeds like Parthenium and Lantana,” fear researchers from the Department of Botany, Shivaji University, Kolhapur, who have conducted the study. The research findings have been published in journal Current Science. 

“It does not affect any specific crop, but is growing in the cultivated fields of drier parts of Karnataka, adversely affecting on the growth of many crops just like other weeds such as Parthenium, Vernonia, Tridax, Chromolaena,” Jagdissh Dalavi,who was involved in the identification of the new weed, told India Science Wire. 

In a casual look, the weed can be mistaken with Vernonia cinereal, another commonly found weed, except that the seeds of Ethulia are without the parachute mechanism which helps in seed dispersal. The weed belongs to a widespread family of decorative plants called Asteraceae. It grows to about two feet height with very sharp leaves and an inflorescence at the top. It was discovered during a survey in the dry fields of Belagavi district of Karnataka. 

The possibility of it spreading fast is greater because plants of the Asteraceae family are highly evolved among the flower bearing plants, produce large number of seeds which can disperse far and wide. They are also resistant to diseases, insect pests and are repulsive to grazing animals. Their tremendous ability to reproduce makes them highly invasive weeds

So far it has been reported only from Karnataka. There are some possibilities of occurrence of this species in similar habitats. Only two other species of Ethulia have been found in India, and that too in the North Eastern region. But the new weed Ethulia gracilis is much different from them and resembles a plant growing in Africa. 

“How this weed came into India is a serious issue because it is a native of Africa. India has imported Cajanus and some other crops from Africa, and there are chances of mixing of some seeds of this weed with those,” felt Dalvi. At present, there is no specific herbicide or weedicide for the Ethulia gracilis. 

Besides Jagadish Dalavi, the research team included Sneha Bramhadande, Chirag Narayankar, Suraj Patil and Shrirang Yadav. 
Courtesy :  India Science Wire