Damage symptoms
The impact of a PepMV infection for the tomato grower is variable. Several factors contribute to this variability. The genetic identity of the virus – which isolate of which strain – that causes the infection is one them. The moment in the crop cycle when the infection takes place is another factor that might have an important impact on the damage that is caused. For instance, an infection early in the season, when the plant does not yet bear fruit, will typically cause less losses than when the infection takes place when the plants are heavily laden. Typical of the damage caused by PepMV is, that it is very intense for a few weeks and then disappears to eventually return later in the season. This means that damage can be more severe during a certain period of the year, with 50-60% non-marketable fruits.
Moreover, some tomato varieties are more susceptible to quality losses due to PepMV than others and climate also has an impact. In general, when a plant has more stress for whatever reason, losses will be much higher.
Symptoms typically appear 2-3 weeks after infection and can significantly impact the yield and quality of crops like tomatoes.
Typical symptoms are:
Leaves & stems
- Nettle-like heads and/or bubbling of the leaves
- Stunted leaf growth
- Leaves have a pale or grey colour
- Necrotic and dying leaves
- Yellow (chlorotic) and brown (necrotic) mosaic pattern on the leaves
- Yellow spots on older leaves and interveinal chlorosis
- Necrosis of the stems
Fruit
- Yellow or orange mottling on the tomatoes
- Flame-like pattern on the tomatoes
- Cracks and damage to the fruit (splitting open)
Symptoms on fruits can appear with or without symptoms on the rest of the plant, depending on the tomato variety, environmental conditions and PepMV isolate.
