Sorghum golden mosaic virus

The hallmark symptom of the infection is the development of a characteristic golden-yellow mosaic pattern on the leaf blades of the affected sorghum plants.

Infected plants exhibit stunted growth and a general decline in developmental vigor compared to healthy plants growing under the same field conditions.

Chlorosis of the leaf tissue often progresses into necrosis, leading to tissue death and a significant reduction in the photosynthetic surface area.

Reproductive development is also negatively impacted, resulting in malformed panicles with reduced grain set and overall diminished yield per plant.

The manifestation of these symptoms is typically more pronounced during peak growth periods, coinciding with environmental conditions that favor rapid viral replication.

The causative agent of this disease is a virus belonging to the genus Aureusvirus within the Tombusviridae family, featuring spherical virions containing single-stranded RNA.

This pathogen primarily infects plants of the Poaceae family, with various cultivars of grain and forage sorghum being the most susceptible hosts.

The virus is disseminated within agricultural fields predominantly by insect vectors, such as aphids, which acquire and transmit the pathogen while feeding.

Mechanical transmission is also possible during cultivation practices where infected plant tissues come into contact with healthy plants, although it is less frequent than vector-borne spread.

The virus acts as a persistent pathogen, surviving the winter in the rhizomes of perennial weed grasses which serve as primary reservoirs before the next growing season.

The prevalence of the disease is heavily dependent on the population dynamics of insect vectors, which thrive in warm, dry weather conditions.

High humidity combined with moderate warmth creates an ideal microclimate for the survival and dispersal of the vectors throughout the crop canopy.

The presence of wild grasses in and around fields acts as a critical factor for the maintenance and continuous spread of the virus throughout the season.

Delayed planting dates may leave young, vulnerable sorghum seedlings exposed to higher rates of viral infection from migrating insects.

Plant stress, often caused by drought, poor soil fertility, or chemical exposure, renders the crops more susceptible to significant damage upon viral infection.

The primary economic impact of the virus is a drastic reduction in total biomass and grain yield, making it a significant concern for commercial growers.

Grain quality is severely degraded by the infection, affecting the nutritional value and marketability of the harvested sorghum crop.

Forage production is particularly affected, as the disease reduces the overall quantity and quality of silage or green fodder available for livestock.

Severe infestations can lead to thinning stands, reducing the plant density and overall efficiency of the agricultural operation.

Additional costs associated with disease management, including monitoring and insecticide applications, further increase the economic burden on the producer.

Sanitation is a vital component of control, requiring the removal of weeds around the field perimeter to eliminate viral reservoirs.

The deployment of virus-resistant or tolerant sorghum hybrids remains the most reliable strategy for long-term disease management and yield protection.

Strategic insecticide treatments should be applied to manage aphid populations and limit the transmission of the virus to healthy crops.

Maintaining proper spatial isolation between new sorghum plantings and established perennial grass areas helps to reduce the risk of initial infection.

Using certified, disease-free seed ensures that the crop starts with a clean baseline, reducing the likelihood of early-stage viral outbreaks.