Avoiding Botrytis in Tomatoes
24th Feb 2000
I have had trouble over the past few years with my tomatoes, they grow well and the crop is excellent, but they succumbed to the Botrytis disease with a vengeance. So bad was the disease that I wasn't able to show a single tomato, the worst year that I have ever had. Charles Maisey from South Wales, one of the top tomato growers in the country, also had a disastrous year although he did manage to stage a few dishes early on.
Frank Mercer however who lives in the Wirral had no such problems and was able to stage some top quality dishes winning at the highest level. Franks' answer to this problem was to say that we all try and get too many plants into a given space allowing the disease to establish quickly. Planting less plants giving them more room in between each other will help in two ways, air movement can be improved as well as preventing the plants foliage from rubbing against each other. This way the disease is spread from plant to plant and before you know it, the whole greenhouse is infected.
I shall certainly take heed of his word but I am also having two new varieties grown on trial for me this year that are very strong against Botrytis, if they prove to have the qualities necessary for the show bench I shall certainly be growing them. Most of the newer varieties on the market today are either the 'Long Season' types or the newer varieties such as those that I am currently having on trial which are called 'Cluster Tomatoes"
The Long Season types are those such as Solution and Ferrari that stay red and firm on the plant for days and are excellent for showing as they give the exhibitor more tomatoes to select from. The Cluster Tomatoes have been bred differently, they sell as a complete truss and the tomatoes stay red and firm on the truss for a few weeks. The Cluster tomatoes have a lot going for them as the plants are easy to grow with good vigour and a generative habit. The special breeding for clusters provides a variety with a beautiful fish bone shaped truss allowing sufficient space for all the fruit giving uniform ripening along the truss. On top of that the fruit has good taste, strong tolerance against cracking and the fruit set easily.
As these modern varieties have been bred so that the complete truss is sold on a tray, they have a very strong fruit attachment so that you can no longer snap a tomato off the truss by pressing against the knuckle just above the calyx. In future they will have to be cut off with a sharp knife or scissors and the calyx, believe it or not, will stay green and attached to the tomato for up to a month; the trusses are usually thinned to leave six fruits per truss.
People have become increasingly concerned regarding the use of Genetic modification in tomatoes and I specifically asked the breeder of these new varieties whether or not they were part of a genetically modified programme. His reply was very positive in that there are no genetically modified tomatoes available in this country or Europe, good news indeed. The down fall of these are the price of the seed, they are very expensive, but should they prove to as good as the write up from the breeder, then I shall definitely be selling them in my seed catalogue next year.
I intend to sow my tomatoes this week which should give me fruits for staging from mid August onwards as I still like to have a go at the Anglesey County Show. Tomato seed are large enough to sow singly so do take time to space them out if you are sowing them in a seed tray. Space the seed at least an inch apart and press them lightly into the seed compost and then cover them with the same fine compost or with fine vermiculite which I have used successfully over the past few seasons. With the Levington professional range of F1 the compost is fine enough as it is straight from the bag, but if you intend to use Levington Multi Purpose then it's better to pass the compost through a fine sieve.
Tomatoes germinate quickly and easily in a propagator and should be through in about seven days, do make sure that when they are at the correct size for transplanting that you have the greenhouse warm enough for them. I like to transplant mine when the seedling leaf is fully stretched out and just before the main or proper leaf is to be seen. Pot them on into three inch pots using Levington M2 or even the compost from a fresh Gro Bag that's been brought inside the greenhouse to warm up for a few days. When potting them up, make sure that you only hold the young seedling by the leaf, never hold them by the stem as they will bruise easily and collapse on you within a few days.
Make a hole in the compost right down to the bottom of the pot and carefully push the roots of the seedling right down until the seedling leaf is nearly sitting on top of the compost. This is very important as the tiny hairs along the young stem will develop into a root system which gives you a far superior plant to any that are transplanted with the stem above the compost. Utilising the stem of the plant to generate more roots can be advantageous right through to planting time giving you a very strong plant when in it's final growing position.
The varieties that I shall be sowing will be Solution, Durinta, Ferrari and one or two of the newer varieties that as yet have no name.