Professional tomato growers are very conscious of the diseases that are likely to affect their plants. If growing outside each season, and in the same soil, a grower will have a good idea “what lurks beneath!” and how to combat it.
However, for the home gardener, a little understanding of diseases and how to avoid them, will go a long way.
There are many diseases that affect tomato plants but here are a few very common ones:
- Verticillium Wilt
- Fusarium Wilt
Disease resistant codes such as VFN = Verticillium Wilt, Fusarium Wilt and Nematodes are often mentioned or listed on seed packets – Roma VF for example
The two wilts (V+F) are fungal diseases that stop-up a plant’s plumbing. Nematodes (N) are microscopic worms that attack roots, and again, effect a plant’s plumbing by restricting water and nutrient absorption by the roots.
Blight tolerant varieties – blight is a most serious fungal disease as it spreads easily and can destroy all your plants in a couple of weeks! Legend, Ferline F1 and Losetto F1 are blight tolerant and put-up some resistance – but they are not totally immune.
The new Crimson Crush and Mountain Magic varieties are blight resistant and their fruit can escape blight – even in a warm wet July and August!
Choose plants with vigorous growth
A healthy, quick growing tomato plant may not be immune to disease but will be able to last longer before being effected and often produce ripe fruit before being “bumped off!”.
Most Hybrids have vigorous growth because they are a first generation cross – an F1.
Grafting seedlings for extra disease resistance
If you are up for a challenge, try grafting your own rootstock. It’s fun but a bit fiddly – yet it will provide all the above mentioned advantages.
It’s unfortunate that heirloom varieties aren’t always the most disease resistant, or provide the quantity of tomatoes that many hybrids do. However, grafting a vigorous and disease resistant rootstock to an heirloom can improve performance – if that’s what you wish to do of course!
Here’s a comprehensive list on disease resistant varieties. Thank you Cornell University – Vegetable MD Online.