Distribution, biology, and agricultural importance of Galinsoga parviflora (Asteraceae)

Galinsoga parviflora, an annual dicot species of the family Asteraceae, is a common herb that is often found in disturbed habitats and agricultural areas in many parts of the temperate and subtropical regions of the world. It is a native of tropical America and the center of its origin is thought to be the mountainous area of Central America. Galinsoga parviflora is considered to be a common weed in several crops of major importance, such as wheat, corn, cotton, tobacco, sugarbeet, tomato, pepper, potato, bean, onion, cabbage, garlic, coffee, citrus, banana, and strawberry; it is frequently found in gardens and uncultivated areas. It succeeds particularly in moist soils and it is favored by a long photoperiod and high light intensity. The significant features of the plant, such as the lack of seed dormancy, rapid growth and development, early flowering, many generations per growing season, production of a great number of seed in a wide range of environmental circumstances, and the ability for easy vegetative reproduction under favorable conditions predispose the plant to be a troublesome weed. These features allow the easy distribution and rapid establishment of the weed in large populations, a fact that often makes this weed difficult to control. Galinsoga parviflora competes strongly, particularly with irrigated crops of short height, and it might also hinder crop harvest. The management of G. parviflora can be achieved by manual weeding, repeated soil cultivation, crop rotation, mulching, and herbicide application. The plant is reported to be edible and is used also for medicinal purposes.