Tomato leaf curl Sinaloa virus

This virus is transmitted in a persistent, circulative manner by the silverleaf whitefly, Bemisia tabaci, which remains infectious after a feeding period.

The pathogen is highly selective, meaning that only specific biotypes of insect vectors are efficient at transmitting the virus from plant to plant.

Once inside the plant, the virus moves systemically, colonizing all tissues and interfering with normal physiological processes.

Due to the biology of the virus, its management relies heavily on controlling the vector populations that introduce the pathogen into the crop.

The primary symptom is a distinct leaf curling and upward rolling of the leaflets, which gives the infected plant a very specific stunted appearance.

Plants exhibit severe chlorosis, often characterized by yellowing of the leaf margins while the veins remain green, creating a mosaic pattern.

Internode length is significantly reduced, leading to a bunched or rosette-like growth habit at the plant's apex.

Early-stage infection often leads to flower drop, preventing fruit set and drastically reducing the overall marketable yield.

• Upward leaf curling.
• Severe chlorosis and yellowing.
• Stunting of the main stem.
• Flower and young fruit abscission.

Warm and arid climates significantly favor the buildup of whitefly populations, thereby increasing the prevalence of the virus in the field.

Large-scale tomato monocultures provide an ideal environment for the virus to spread rapidly once an initial vector population is established.

Wild solanaceous weeds growing near commercial fields act as natural reservoirs for both the virus and its whitefly vector during the off-season.

Poor sanitation practices, such as leaving crop debris after harvest, can lead to the survival and transmission of the virus to subsequent planting cycles.

Rapid movement of winged adult whiteflies between fields due to wind or agricultural machinery accelerates the dissemination of the viral infection.

The disease causes profound economic losses by inducing permanent stunting, which renders the infected tomato plants unproductive.

Fruit that manages to develop is often small, misshapen, and lacks the necessary quality parameters required for commercial markets.

In cases of early-season infection, entire blocks of tomato crops may face complete failure, leading to total yield loss for the grower.

The systemic nature of the pathogen makes it impossible to save an infected plant, necessitating immediate rogueing to protect the rest of the field.

Increased expenditures on chemical insecticides to manage whitefly populations significantly elevate the cost of production in affected regions.

Effective management requires an integrated pest management (IPM) approach centered on intensive control of whitefly populations using targeted insecticides.

Physical barriers such as insect-proof netting in greenhouses are highly recommended to prevent vectors from accessing young plants.

Rigorous weed management, both inside and outside the production area, is essential to eliminate reservoirs of the virus.

Rogueing infected plants at the very first sign of symptoms helps reduce the amount of inoculum available for further transmission.

The selection of resistant or tolerant tomato cultivars remains the most sustainable and efficient long-term strategy for managing the disease.