Invasive Threat: Cuscuta Dodder’s Encroachment                                          

Introduction:

• The Chengalpet forests and Vedanthangal Bird Sanctuary face a menacing intruder: Cuscuta dodder, an invasive weed. Its unchecked spread poses a significant danger to the local ecology, vegetation, and the habitat of migratory birds.

Understanding Cuscuta Dodder:

• Originally hailing from North America, Cuscuta dodder is a parasitic vine devoid of roots. It has already infiltrated vast expanses of trees within the reserve forests and has begun its encroachment into India’s oldest bird sanctuary. The modus operandi of this holoparasitic plant involves enveloping the host plant with a dense canopy and sending out numerous tendrils, eventually leading to the strangulation and demise of the host.

Impact and Distribution:

• A technical paper by the National Research Centre for Weed Science highlights the severe threat posed by Cuscuta across various regions in India, particularly in oilseeds, pulses, and fodder crops. States such as Andhra Pradesh, Chhattisgarh, Gujarat, Orissa, West Bengal, and parts of Madhya Pradesh are especially vulnerable to its invasion, both in rain-fed and irrigated conditions. Moreover, this weed has garnered attention globally, with legislation in 25 countries categorizing it as a ‘declared noxious weed,’ thereby prohibiting the movement of its seeds and plant material. Notably, in the United States, it stands as the sole weed seed whose transportation is prohibited across all states.

Persistence and Propagation:

• The seeds of Cuscuta dodder possess remarkable resilience, with a spheroid shape and a sturdy coat enabling them to survive for up to 50 years in dry storage and at least a decade in the field. Unlike other parasitic plants reliant on specific stimuli for germination, Cuscuta seeds exhibit a unique ability to sprout without such triggers.

Conclusion:

• The invasion of Cuscuta dodder presents a pressing ecological challenge, threatening not only the delicate balance of ecosystems but also agricultural productivity. Urgent measures are imperative to curb its spread and safeguard the biodiversity and natural habitats that are under siege.