Grafting tomatoes

The rootstock is a variety (in my case F1 submarine) that is resistant to viruses and other tomato ailments. In my greenhouse I have either or both of verticillum and fusarium wilts caused by fungi. The plants would crop very poorly and finish early if planted there.

Apparently vermicompost can help protect plants from verticillium and fusarium. Also there's a fungus called Trichoderma which helps, you can buy it in granular form from a few places.