What would happend to the producers if a virus broke out among the primary consumer and wiped out mostly of the species

Producers would be able to grow exponentialy due to less consumers eating them, Until the consumer population was able to recover
 

Well I think from what I remember, Primary consumers eat vegitation and so if a virus broke out, if it wiped out most of the PLANTS then primary consumers would probably die out or just have less of them with not a lot of food, But if the virus wiped out other consumers such as carnivores, then the area would be over populated with no predators to keep the numbers of primary consumers at a stable amount. Hope this helped!! :D