Marc-André Goulet, grower in Nantes

After many years' experience with Grodan Master, Marc-André Goulet, a tomato grower in the Nantes region, discovered the advantages of Grodan Prestige. He quickly got to grips with the more responsive way of working.

After initial experience as cultivation manager for a greenhouse manufacturer in the Nantes region, Marc-André Goulet moved to the Chenardière site in Haute-Goulaine in 1993, a stone's throw from his family's farm and not much further from that of his first employer. Of the 2.4 ha of greenhouses on the Chenardière site, M.-A. Goulet undertook the renovation in two stages: 1.4 ha as soon as he set up business, and 1 ha a few years later. M.-A. Goulet's business expanded in 2000 when he took over the family farm and the previous generation retired. Today, M.-A. Goulet produces only tomatoes, in a total of 8.4 ha of greenhouses, the latest of which were built in 2014 and 2016 (semi-enclosed). Production is split 1/3 round tomatoes, 1/3 trusses and 1/3 elongated cherries. All marketing is handled by the Océane cooperative group.

"All the land on the farm is now occupied by greenhouses. The only way to develop the business is to renovate the existing facilities. But current trends are dictated above all by the uncertain evolution of many production factors", emphasises M.-A. Goulet.

Prestige is a more draining slab with which humidity can be varied quickly, both upwards and downwards. It responds better to the demands of the grower, who can then more easily guide the behaviour of the plants, particularly at the start or end of cultivation, when the climatic variations over the day are at their widest.

"Compared with Master slabs, which tend to stay wetter, Prestige dries out the substrate more quickly. This is a real advantage, especially when we tend, as we did this year, to manage heating as closely as possible, to prevent our production costs from spiralling out of control", explains M.-A. Goulet. "Prestige is a very interesting slab, but it does require some adaptations in terms of irrigation management. When the plants are hard at work, you have to start watering a little earlier and extend it a little later at the end of the day. And don't be surprised if you don't see any roots, especially at the start of cultivation. With Prestige, colonisation of the substrate occurs first inside the slab", adds M.-A. Goulet, who appreciates the behaviour of this slab. "It also helps to maintain a more stable conductivity, and that's a positive point in my book. On the other hand, Prestige is more difficult to re-wet in the event of a watering accident. It's easy to re-moisten a Master slab with a good watering, even in extreme situations and in the case of wilted plants. With Prestige, on the other hand, this type of incident has to be dealt with manually". The two slabs, Prestige and Master, have many qualities: Prestige is drier and more reactive, Master has more inertia but can be a safety solution in certain situations. The results at the end of the season will enable M.-A. Goulet to refine the comparison between the two slab types. Energy uncertainty could work in Prestige's favour. M.-A. Goulet also uses Plantop cubes supplied by his plant grower. In addition to the perfect compatibility between the cubes and Grodan slabs, M.-A. Goulet appreciates the fact that this type of cube allows him to extend the pre-planting period if necessary. This period, which generally lasts 2 to 3 weeks, can be extended to a month to wait for a favourable period. "It's more comfortable," concludes M.-A. Goulet.