Jatropha mosaic

Pathogen and type of disease. The disease is caused by Begomovirus jatrophamusivi, a member of the Geminiviridae family. It is a systemic viral infection that infiltrates the plant's phloem, causing systemic physiological stress, inhibiting development, and disrupting normal biological processes.

Host plants. The virus primarily infects Jatropha curcas, a plant valued for its high oil content. While it is highly specific to Jatropha, the virus can persist in various weed species, which act as secondary hosts in tropical agroecosystems.

Symptoms and signs of infection. The clinical manifestation starts with mosaic-like chlorosis on young leaves. As the disease progresses, leaves exhibit curling, wrinkling, and significant size reduction. Affected plants often show stunted height, reduced flowering, and a general decline in vigor, making the crop look thin and sparse.

Conditions for development and spread. Transmission is facilitated by the whitefly Bemisia tabaci, which acts as the principal vector. High temperatures and drought conditions are optimal for the proliferation of whitefly populations, leading to rapid and widespread dispersal of the virus throughout the plantation.

Harmfulness and protection measures. The virus poses a significant threat to agricultural productivity by drastically reducing seed yield and oil quality. Protection and management strategies include:

• Integrated pest management (IPM) to suppress whitefly populations.
• Rogueing of infected symptomatic plants to limit the viral reservoir.
• Use of virus-free planting stock and potentially resistant cultivars.
• Maintaining field hygiene by clearing surrounding weeds and host-reservoir plants.