Cotton leaf curl Bangalore virus

The most distinctive symptom is the downward or upward curling of leaves, often accompanied by the swelling and darkening of leaf veins.

Infected plants show severe stunting and reduced leaf size. The leaves may develop yellow patches or a general chlorotic appearance, indicating impaired photosynthesis.

Reproductive growth is drastically affected. Plants exhibit poor bud formation, and premature flower shedding is common, leading to a significant loss of bolls.

Plants often produce excessive lateral shoots, resulting in a bushy, stunted phenotype that is easily distinguishable from healthy cotton bushes.

• Leaf curling and deformation
• Vein swelling and discoloration
• Stunting and dwarfing
• Reduced floral development
• Chlorosis and mosaic patterns

The pathogen is Begomovirus gossypibangalorense, a member of the Geminiviridae family. It is a plant-infecting virus with a circular single-stranded DNA genome.

The disease is classified as a viral leaf curl infection. It is a systemic pathogen that colonizes the phloem, affecting the overall physiological integrity of the cotton plant.

This virus is a specialized pathogen for Malvaceous plants. It is known for its high genetic diversity and rapid evolution through recombination with other begomoviruses.

The virions possess the characteristic geminate structure, which consists of two incomplete icosahedral capsids joined together, protecting the viral DNA.

Transmission occurs exclusively via the whitefly Bemisia tabaci in a circulative, persistent manner, meaning the insect can transmit the virus throughout its adult life.

The presence of the whitefly Bemisia tabaci is the primary prerequisite for the spread of the virus. High population densities increase the infection rate.

Environmental conditions favoring the reproduction of whiteflies, such as warm temperatures and high humidity, significantly accelerate the spread of the disease.

Intensive farming practices that allow for overlapping cotton cropping seasons provide a continuous bridge for the virus to persist in the environment.

The presence of alternative weed hosts in the surrounding areas serves as a reservoir for both the virus and the whitefly vector.

Poor field management, including lack of spatial isolation between old and new crops, allows the virus to migrate rapidly within the plantation.

The primary economic impact is a drastic reduction in seed cotton yield. Severe early-season infections can lead to near-total crop failure.

The quality of cotton lint is significantly compromised, resulting in shorter fibers that do not meet textile industry requirements for spinning.

Viral infection weakens the physiological resistance of the plant, making it more susceptible to secondary fungal or bacterial pathogens.

Farmers face increased operational costs due to the intensive application of pesticides required to control whitefly populations.

Export potential is severely limited due to stringent phytosanitary regulations aimed at preventing the introduction of the virus into disease-free regions.

The most effective long-term strategy is the development and cultivation of resistant or tolerant cotton varieties using advanced breeding or biotechnology.

Integrated Pest Management (IPM) focusing on the control of the whitefly population using systemic insecticides is crucial for minimizing viral outbreaks.

Rigorous field hygiene, including the removal of weeds and debris that serve as reservoirs, is essential to decrease the inoculum pressure.

Implementing a crop-free period, or "cotton-free season," helps to break the viral cycle and significantly reduces vector populations in the area.

Strategic crop planning, including the use of trap crops and spatial separation, provides a physical barrier against the migration of the whitefly vector.