Evolvulus nummularius

Evolvulus nummularius belongs to the Convolvulaceae family. It is a perennial herbaceous plant characterized by trailing stems that root at the nodes, creating dense, mat-like ground cover. As a persistent perennial weed, it utilizes both sexual and vegetative propagation to colonize new areas efficiently.

Originating in the tropical and subtropical regions of the Americas, this species has become a global invasive problem. It is commonly found in damp grasslands, along roadsides, and in urban green spaces. More significantly, it has established itself as a difficult-to-control weed in agricultural fields, particularly in tea plantations, rice paddies, and vegetable production areas.

The biology of Evolvulus nummularius is marked by high adaptability. It can thrive in varying moisture levels, including temporary flooding, and is highly resilient due to its ability to sprout from small stem fragments left in the soil after tillage. This high regenerative capacity makes it extremely difficult to eradicate through manual or mechanical removal alone.

The weed causes significant crop damage by forming thick mats that outcompete crops for nutrients, sunlight, and moisture. In addition to direct resource competition, it can serve as a reservoir for various plant pathogens and pests, which can decrease the overall health and yield of the primary crops in the field.

Effective control requires an integrated approach. Cultural practices, such as intensive mechanical tillage to exhaust the root system, are essential. Chemical control involves the application of systemic herbicides; however, timing is critical. Because of its resilience, repeated applications or tank mixes of systemic chemicals are often necessary to fully suppress the weed population without harming the crop.