Sugarcane white streak

The primary symptom of the disease is the appearance of distinct, narrow, longitudinal streaks of white or cream color on the leaves of sugarcane. These streaks are strictly parallel to the leaf veins, giving the plant a characteristic variegated appearance.

As the disease progresses, the streaks may elongate and widen, often merging with each other. In severe cases, the affected leaves become almost completely bleached, which sharply reduces the photosynthetically active surface area of the plant.

Highly infected plants exhibit general growth stunting and a significant delay in development compared to healthy specimens. The stems become thinner, and the internodes often appear shortened.

The infection can affect not only mature leaves but also young shoots, significantly impacting the viability of seedlings during the first months of vegetation. External signs are particularly noticeable during periods of active crop growth.

Changes in leaf pigmentation serve as a key diagnostic sign, allowing specialists to visually identify the viral infection at early stages under field conditions.

The disease is caused by Mastrevirus saccharumalbusvenae, a virus of the genus Mastrevirus belonging to the Geminiviridae family. These pathogens are characterized by a single-stranded circular DNA genome and specialize in infecting various species of cereals.

The virus localizes predominantly in the phloem cells of the host plant, which hinders the plant's natural defense against the infection. In nature, the virus is transmitted by specific insect vectors, most commonly leafhoppers.

During feeding on an infected plant, the insect ingests viral particles, which then persist in the vector's body for a long time. The efficiency of transmission is directly dependent on the population of vectors present in the plantation.

The spread of the disease correlates closely with the breeding and migration cycles of the insect vectors. Mechanical transmission of the virus through tools or plant sap in field conditions occurs extremely rarely.

The virus possesses a high degree of specialization, which limits its host range primarily to representatives of the Poaceae family, including cultivated sugarcane and certain wild grasses.

The development of white streak epidemics depends directly on weather conditions that favor the reproduction and active migration of insect vectors. Warm and humid weather provides an ideal environment for these vectors.

The intensity of viral spread increases during periods when leafhopper populations reach their peak. High temperatures facilitate accelerated metabolism in insect bodies, which increases the frequency of their feeding on plants.

The presence of alternative virus sources, such as grassy weeds growing along field perimeters, significantly increases the risk of commercial crop infection. Weeds serve as pathogen reservoirs during off-seasons.

Failure to observe crop rotation and the use of infected planting material are critical factors contributing to virus accumulation in the agrocenosis. The infection is easily transmitted through the use of cuttings from diseased plants.

Plants weakened by poor care or nutrient deficiencies become more susceptible to viral invasion, facilitating the colonization of sugarcane tissues by the pathogen.

The primary consequence of the disease is a substantial reduction in sugar yield per hectare. The photosynthetic activity of affected plants drops, leading to low biomass accumulation and reduced sucrose content in the stems.

Viral infection leads to crop thinning due to the death of weak sprouts or a decrease in their ability for vegetative propagation. This forces farmers to incur additional costs for replanting affected areas.

The quality of raw material harvested from infected plantations declines, complicating processing at sugar mills. The virus alters the biochemical composition of the sugarcane juice.

Long-term persistence of the virus in vegetative material leads to gradual degradation of the cultivar's characteristics. This makes it impossible to use infected material as a foundation for future stock.

Economic losses include not only direct losses from yield reduction but also indirect costs associated with implementing phytosanitary measures to contain the spread of the infection.

The cornerstone of disease control is the use of healthy, certified planting material. Rigorous selection of cuttings from virus-free plants is the most effective prevention method.

The most important measure is managing the population of insect vectors. The application of systemic insecticides during periods of peak leafhopper activity significantly reduces the rate of disease spread.

Spatial isolation of new plantations from old, infected areas helps limit the introduction of the virus by insect vectors. It is also necessary to regularly perform weed control.

Timely detection and removal of infected stools at the beginning of the season help prevent the mass spread of the virus to neighboring plants. Monitoring of crop conditions should be conducted regularly.

• Utilization of virus-resistant crop varieties.
• Adherence to optimal planting schedules.
• Execution of phytosanitary roguing in plantations.
• Maintenance of high-level agronomic practices.