The Rootstock Company. The name says it all, this Dutch breeding company with international ambitions develops rootstocks. From the moment that growers started grafting fruit vegetables in the 1990s, this has been a crucial part of the plant.

Yet for a long time there was no player who focused exclusively on the ‘basis of the plant’. A good reason for Ronald Visser to start The Rootstock Company (TRC) in 2015. The company, based in Bleiswijk, has now reached the stage where, after extensive testing, significant commercial steps are being taken in the market, so it is high time to hear how they are doing.

Ronald Visser and Arnoud Roozen

From first screenings to entire greenhouses
The first steps with self-developed rootstocks were taken in the 2017-2018 season. “At the time, we carried out the first screenings in the cultivation of tomatoes on substrate in the Netherlands,” says Ronald.

Subsequently, the hybrid varieties were scaled up step by step. As it goes, it went from a few plants to rows, to a path, a bay and now there are growers who have also filled their entire greenhouse with plants that are grafted on a TRC rootstock.

Arnoud Roozen also experienced those recent major growth steps. He has been commercial manager at the rootstock specialist since April 2019. Unlike Ronald, who first got to know the sector in financial positions, among other things, Arnoud has been active in the sector in various roles for over fifteen years. Just like Ronald, he is now convinced that TRC is on the brink of huge growth, in both conventional substrate cultivation and (organic) soil-bound cultivation.

Up to now, these are the growth steps that have been taken in the tomato substrate market in Europe

Vigorous growth
The rootstock specialist’s showpiece for tomato and eggplant on substrate is Astrolite. Arnoud: “We attract a lot of attention from the market with this rootstock variety. You notice that growers are interested and are looking for ways to generate higher yields. This is possible with our very powerful rootstock. Comparison tests with the references from the market show that a higher yield is feasible.”

Just like the market for culture varieties, the market for rootstocks is not standing still. Nevertheless, developments here are somewhat slower. Not surprising, because fewer characteristics are relevant in rootstocks. All kinds of colors and shapes, do not play a role for rootstock like they do for cultivated varieties. Ronald: “In short, resistance and vigor are the most important aspects here.”

Various tests have shown that Astrolite yields more production compared to the references in the market. Above a test from the 2019-2020 season. Click here to enlarge.

‘Friend to all’
Astrolite excels on that last point in particular, according to both men. Arnoud: “The resistances of this rootstock are not unique, but we believe that the vigor is. The aim is to always make it a ‘friend for all’ as much as possible when developing a rootstock, on which many culture varieties can thrive. Along the way, we have already seen many good matches between culture variety and rootstock in local market and abroad, although this also depends on conditions such as the cultivation method used by the grower and the age of a greenhouse.”

In organic cultivation, TRC says it is even slightly further ahead than in the substrate market. In Europe it is expected that in the 2020-2021 season there will be approximately 135 hectares with TRC rootstocks for tomatoes, cucumbers and peppers. Ronald: “In the organic market, where cucumbers and bell peppers are grafted in addition to eggplant and tomato, we have become more established. In that market, the focus is even more on resistance than in substrate cultivation.”

The same applies to traditional soil-bound cultivation. For example in Mexico, where a rootstock with fusarium-3 (Fol-2) resistance is very popular. “Our rootstock TRC 51901 offers it, again in addition to good vigor,” says Ronald, who also explains that for the 2021-2022 season in Spain and Italy, a large-scale introduction to the traditional soil boind cultivation will take place in tomatoes on approximately 60 hectares.

The cucumber rootstocks in the photo are both from TRC. Ardito is a commonly used rootstock in Northern, Western and Central European organic cultivation. TRC11550 is a newcomer with a higher resistance to nematodes. This is clearly visible in the photo. The roots of the rootstock on the right are clean, root knot formation is clearly visible on the left.

Reduced ToBRFV risk
An important development in both the organic and the substrate market is the advance of the Tomato Brown Rugose Fruit Virus (ToBRFV). Ronald: “Minimizing the risk of ToBRFV contamination in our seeds became one of our main priorities at the end of 2019. As a result, as far as we know, we are currently the only breeding to take a leaf sample from all plants twice in our production cycle. If that sample is negative, we know that the plant is healthy and therefore all harvested seeds are too. By doing this a test twice, once halfway through the cultivation and once when the last cluster has been harvested, and in addition to the regular seed tests, we limit the risks as much as possible. ”

Naturally, this also involves costs, because how far can, will and must you go in avoiding risks? “We think we have found the right balance with this protocol.” And crossbreeding a ToBRFV resistance into a rootstock? “That could be possible, although we wonder whether a grower is always one hundred percent protected. It remains a combination of rootstock and scion culture variety. We are currently testing all our material for possible ToBRFV resistance that may already be present. We have indications that there are already resistances in our material. ”

25 years
That would be a ‘nice bonus’ for the rootstock specialist. In any case, as all breeding companies are used to, development will not be static “Although we are of course hoping that in 25 years’ time our rootstocks will still be firmly anchored in the national and international market”, Ronald concludes with a laugh. “In any case, the unique characteristics will not be the issue.”

For more information:
The Rootstock Company

Ronald Visser
+31 (0)6 51 86 92 89

Arnoud Roozen
+31 (0)6 89 99 09 55