Ringspot virus of spinach affects the appearance and palatability of the leaves. It is a common disease among many other plants in at least 30 different families. Tobacco ringspot on spinach rarely causes plants to die, but the foliage is diminished, faded and reduced. In a crop where the foliage is the harvest, such diseases can have serious affects. Learn the signs and some preventions for this disease.
Signs of Spinach Tobacco Ringspot
Spinach with tobacco ringspot virus is a disease of minor concern. This is because it is not very common and does not affect an entire crop as a rule. Tobacco ringspot is a very serious disease in soybean production, however, causing bud blight and failure to produce pods. The disease does not spread from plant to plant and is, therefore, not considered an infectious issue. That being said, when it does occur, the edible part of the plant is usually unusable.
Young or mature plants can develop ringspot virus of spinach. The youngest foliage shows the first signs with necrotic yellow spots evident. As the disease progresses, these will enlarge to form wider yellow patches. Leaves may be dwarfed and roll inward. The edges of the leaves will turn bronze in color. The petioles will also discolor and sometimes deform.
Severely affected plants wilt and are stunted. The disease is systemic and moves from the roots to the leaves. There is no cure for the disease, so prevention is the first path to control.
Transmission of Spinach Tobacco Ringspot
The disease infects plants through nematodes and infected seed. Seed transmission is probably the most important factor. Luckily, plants that are infected early rarely produce much seed. However, those that acquire the disease later in the season can bloom and set seed.
Nematodes are another cause of spinach with tobacco ringspot virus. The dagger nematode introduces the pathogen through the plant’s roots.
It is also possible to spread the disease through certain insect group’s activities. Among these include grasshoppers, thrips and the tobacco flea beetle may be responsible for introducing tobacco ringspot on spinach.
Preventing Tobacco Ringspot
Purchase certified seed where possible. Do not harvest and save seed from infected beds. If the issue has occurred before, treat the field or bed with nematicide at least one month prior to planting.
There are no sprays or systemic formulas to cure the disease. Plants should be removed and destroyed. Most studies on the disease have been done on soybean crops, of which a few strains are resistant. There are no resistant varieties of spinach to date.
Using disease free seed and ensuring the dagger nematode is not in soil are the primary methods of control and prevention.