The Tunisian branch of the Rainbow Group recently switched from growing bell peppers to snack tomatoes (baby plum tomatoes) in one go. The entire process was supported by former Rainbow partner John van Marrewijk, who relied on cultivation knowledge from Syngenta Vegetable Seeds. 

“We really clicked.”

“I already knew how to manage a business. But I didn’t know anything about growing tomatoes,” says John van Marrewijk, sketching what he faced in January 2022, when he took on a challenge entirely new to him. The Dutch Rainbow Group, in which he was a partner until the end of 2021, had decided to switch from bell peppers to snack tomatoes at its Tunisian branch. 

“It was becoming increasingly difficult to grow bell peppers there”, van Marrewijk explains. “In the final weeks of the growing season, it was too hot to achieve good yields and quality. And the energy costs were also making a big dent in margins.” 

Partnering with Syngenta on Tomato

After visiting several fellow growers to explore the options, the Rainbow Group decided that its Tunisian branch would switch to growing baby plum tomatoes from seed supplied by Syngenta. 

“Tunisia is a low-wage country, so a labor-intensive crop that can be grown there in a cost-competitive way is the most obvious option,” Van Marrewijk said.  “And the climate is great for growing tomatoes with lots of flavor. That means you can turn a profit by growing a more upscale tomato variety with a relatively low production output.”

The switch became van Marrewijk’s new project, to which he could devote his full attention after he had sold his interest in the Rainbow Group. What he needed first and foremost was knowledge about cultivating snack tomatoes. 

Because Van Marrewijk had previously been involved with the cultivation of peppers, he already had contacts at Syngenta, and as they also breed seeds of the Sweetelle variety, it was a logical step to approach them. 

“I immediately got a positive response”, van Marrewijk recalls. John initially spoke with Arthur van Marrewijk (no relation), Syngenta Seeds’ technical manager for greenhouse tomato cultivation, who soon referred him to Rene van Paasen, a former tomato grower who is now a self-employed cultivation consultant and engaged as a cultivation manager at Syngenta Seeds’ Tomato Vision breeding and demonstration complex in Maasland. 

“It was soon clear to me that I didn’t have to look any further,” John continued. “I really clicked with Arthur and Rene; we were on the same page very quickly.”
 

Understanding Tomato Cultivation

Van Marrewijk explains that perhaps the biggest change in the process was that it demanded a different mindset on his part. 

“It’s a completely different way of cultivation. With peppers, ‘hotter is better’, provided that the other conditions are properly controlled. But with snack tomatoes, it’s a completely different story,” he explained. “They demand a lower and, in particular, a more constant temperature. So, you’re working on climate control throughout the day.” 

Van Paasen and Arthur van Marrewijk, who stayed slightly more in the background, taught John the ropes of growing tomatoes. From the stem policy to pollination and from plant load to plant protection, everything was explained to him. 

Prior to the transfer of cultivation knowledge to Tunisia, John made a number of strict agreements with his counterparts. 

“All cultivation knowledge transferred to Tunisia went through me”, he explains. “That made it impossible for any static to develop on the line. Moreover, in Tunisia they knew that any deviations and actions that had not been planned for needed to be discussed with me first. 

“And that went quite well. I think that about 90 to 95% of my instructions and recommendations were followed. And one of the main reasons for this is that the cultivation managers in Tunisia are experienced professionals. They had visited other tomato growers to gather information and they sort out a lot of things on their own.”

Communications between John in Tunisia and Rene and Arthur in the Netherlands mainly took place via WhatsApp and email. 

“We hardly ever spoke over the phone. I took pictures and recorded videos in Tunisia that I instantly shared with Rene and Arthur. And every week I received a file with cultivation and climate data, which I instantly forwarded to them by email,” he said. 

During the transition period, John increased the frequency of his visits to Tunisia to once every fortnight. In the days of bell pepper cultivation, that had been once every three weeks.

Agronomic Support throughout the Season

At the time of this interview, the first growing season had not finished yet, but John could already look back with satisfaction. 

“I remember that our first year of growing bell peppers went less well than has been the case for the snack tomatoes,” he says with a smile. “Of course, there are still some points for improvement; that holds true for both sides. But that is a learning opportunity. The tomatoes have consistently been of a high quality; the only criticism you might have is that the fruit weight could have been a bit higher, but it has consistently stayed within the bandwidth. 

"I am very happy with the results so far. So, I want to give a big compliment to all parties in this process. I really received superb support from Syngenta.”

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Syngenta Seeds in North Africa

Syngenta Seeds has a specialized team in North Africa. The team, based in Morocco, regularly visits representatives of seed breeding companies in several North African countries, including Tunisia. As a result, the team has built up a large local network with many contacts with local tomato growers and other trading partners. Thanks to this position, and of course their cultivation knowledge, Syngenta Seeds is able to provide excellent support and advice.