At Combivliet nearly 13 ha Sassari RZ is grown. On Thursday 27 January we spoke with Patrick Baas.

General information

What made you choose Sassari?
Last year we already grew the variety on a smaller scale and we noticed that, compared with other varieties, it gave a higher production while also doing well as far as quality was concerned. That's why we decided to increase the area this season.

How was the start of the crop?
We began with plant material that was not really uniform, but we knew beforehand that this was part of the variety's make-up. As far as that's concerned I can't exactly say that that is disappointing this season, although there is still some unevenness now. It is also important to grow this variety fast enough - that way the crop won't lose its balance. During the dark, cold period in December we also kept up the speed reasonably well and that meant we came through it all right. Sassari copes well with variable weather anyway: following the past 2 dark weeks the crop is fast gaining in strength now, with a little bit of sun on it. We can easily increase the 24-hour temperature. The variety reacts quickly which makes it easy to steer. Another advantage is that Sassari naturally branches out easily. This allows us to keep temperatures a little more level and we don't have to take too many risks with a low night or high day temperature.

What are the set points at the moment?
At 4.30 pm we take the temperature to the pre-midnight set point of 13.5°C and at 11.00 pm to the night set point of 15.5°C. At 9.30 am we start increasing it to 19.5°C and that is achieved by 12.00 noon. If there's a lot of sunlight we allow another 3°. The ventilation set point is always 1° higher than the temperature set point. We keep the climate active with a min. pipe of 60°C and, in principle, we don't shut the vents. This has the benefit of always having a little more air exchange with the outside environment. That's better for the quality of the leaves and also reduces the botrytis risk.

What is your watering strategy?
We started with the plants beside the planting hole and placed them in the planting holes when we had the third truss. A week later we began the drying-out process. The run-off point is now at  a moisture content of 80% and we'll aim for further drying out of 10%, taking the moisture content down to 70%. We water during the day only, with all the watering rounds coming on between 10.00 am and 2.00 pm. We are using second-year rockwool so we don't water overmuch.

What's going to happen in the next few weeks?
At the moment truss 6 is flowering and next Wednesday we will be picking the first tomatoes. The quality is looking good. And in week 6 we will retain a sideshoot which will take the crop immediately to the final stem density of 3.3 stems/m².

Interview with Tastery RZ grower

On the nursery of Jacobs Rieter 4 ha of Tastery RZ is grown. We spoke with nursery manager Hans Dings on 27 January.

General information

What made you choose Tastery?
Last year we grew it as well but at that time we were unable to get the expected extra production. We think it might have had something to do with the dark year. This year we hope that the extra production will materialise.

How was the start of the crop?
Last year the plants did not get enough heat - this year things were much better. The crop is now looking better and faster. It is looking nicely generative and has more 'stretch' this year. We are even more aware this time how important it is for this vegetative variety to maintain a high speed. Even though it does push up heating costs, we still go for a higher 24-hour temperature and not quite such a low pre-midnight.

What are the set points at the moment?
The pre-midnight set point is 14°C and the night 16°C, with an extra 1.5° if there's a lot of light. This takes the temperature to 17°C by 8.00 in the morning and at midday to 22°C  + at most 2° for light.

How are the plants looking at the moment?
The crop is looking good now. The third truss is flowering. Thanks to the short trusses there is no need for pruning, which makes it an ideal variety when it comes to cutting. An added advantage is that Tastery is not quite so susceptible to splitting. It does really have to make the kilos, though, this year. Because it does not tend to get yellow stems so easily we should get the extra production mainly in autumn.