Indian cassava mosaic virus

Indian cassava mosaic virus (ICMV) is a significant viral pathogen within the Begomovirus genus, Geminiviridae family. It is a major limiting factor in cassava cultivation, particularly in the Indian subcontinent, causing widespread crop losses due to systemic infection.

The primary symptom of the disease is a characteristic mosaic pattern on the leaves, appearing as yellow or pale green chlorotic patches. Infected plants display stunted growth, leaf distortion, and a reduced number of storage roots, which directly results in poor yield and lower economic value for farmers.

The biological transmission of ICMV is largely dependent on the whitefly Bemisia tabaci. The virus is acquired by the vector through sap-feeding and is then transmitted to healthy plants. Furthermore, since cassava is propagated vegetatively, the use of infected stem cuttings is a primary driver of the virus's spread across new planting seasons and geographic regions.

Environmental conditions that favor the proliferation of Bemisia tabaci, such as high ambient temperatures and humidity, facilitate the rapid spread of the virus within and between plantations. Once an area becomes an epicenter for the whitefly, the transmission rate of the virus can lead to severe outbreaks throughout the field.

Controlling this pathogen requires an integrated approach to reduce the incidence and severity of the disease. Key management practices include:

• Utilizing virus-free planting materials derived from tissue culture.
• Implementing strict rogueing procedures to remove infected plants from the fields.
• Applying integrated pest management (IPM) to control whitefly populations.
• Selecting and planting resistant or tolerant cassava cultivars developed through breeding programs.