Fruit & Vegetable Magazine

Features Production Research
Dutch lead innovation in greenhouse berry production


November 30, 1999
By Tamara Leigh

Topics

In Canada, growing berries in greenhouses is relatively rare, but the increasing pressure to extend the growing season to improve profitability has more berry growers weighing the options.

In Canada, growing berries in greenhouses is relatively rare, but the increasing pressure to extend the growing season to improve profitability has more berry growers weighing the options. In Holland, growers have been increasing their investment in greenhouse berry production with impressive results, doubling the yields of conventional Canadian growers.

While they are a long way from competing with the major growing nations like the U.S., Spain, or Turkey, the Dutch are internationally recognized for their expertise in producing premium quality fruit and high yields through intensive crop management.

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“In Holland we go for quality over kilos,” says Willem van Eldik, a senior fruit specialist with DLV Plant BV, a large, multidisciplinary agri-consulting business. DLV undertakes its own scientific research, as well as providing operational, strategic, planning, and turnkey consultancy across all sectors in agriculture and horticulture. Its berry fruit team is widely regarded as the best in northern Europe.

Van Eldik recently presented an overview of DLV’s Quality Monitoring System (QMS), demonstrating Dutch innovation in action. It is a comprehensive crop management tool, initially developed for glasshouse and tunnel grown strawberries.

 “You can manage your nature,” says van Eldik. “Knowledge and control are the keys to innovation.”

Under the QMS system, every aspect of plant propagation and growth is carefully monitored and controlled.

“The focus for glasshouses is before and after the normal season. We count on producing about 12 kilograms per square metre, and now we are going for 15, or about 150,000 kilograms per hectare,” says van Eldik. “You can only get that when you know exactly what is happening when you are growing.”

Like all successful horticulture, it starts with a good plant. DLV works with the propagators to grow the kind of plant that will excel in the glasshouse environment. Elsanta and Sonata are the two most common varieties in Holland. Propagating cuttings from a model plant, they take the best stolon, and establish them in a soil-free environment to encourage a healthy root system, with the right shape and structure to spread and take quickly.

QMS provides support to growers using glasshouses, high tunnels, and field plantings. Each environment comes with its own challenges and monitoring issues. Even in field plantings, the Dutch are using a soil-free system, installing girdles to hold the soil back and putting in coir substrate along with whatever nutrient or water system is required.

Unlike strawberries in Canada, where soil-based berry cultivation is common, 90 per cent of strawberries in Holland are grown in coir substrate, minimizing the risk of disease, and allowing complete control of nutrients, and water. Growing in substrate has also allowed some regions to overcome issues with soil acidity and establish crops that would not otherwise be possible.

To determine the start date of flower initiation DLV growers map the flowers on every plant. Data is collected on the average height of the top flowers, and on the stage of development. They then count back the number of growing day hours (GDH) to determine the timing and quantity of harvest.

“We can forecast your production before you plant,” says van Eldik, an indication of the predictive power of monitoring. “Finding out the details, that’s the innovation. Every detail is worth one kilogram of production.”

Growers using the QMS system enter critical data into DLV’s online monitoring system, such as average temperature, incident light levels, and fruit production for each crop area being monitored. For heated glasshouse crops, the weekly information may be supplemented by additional information like CO2 levels and leaf area index.

From this data, the QMS computer model provides information on how to optimize climate for maximum autumn and spring production, together with predictions on future crop yield and timing. Growers receive a weekly report from their consultant advising them what to do with fertilizers, pesticides or other adjustments to the system.

DLV developed the Strawberry Quality Monitoring System by transferring its expertise in rose cultivation to strawberries.

Over the past 10 years, the consultancy has refined the system through research and work with growers. Now, they are applying the same principles to raspberries, red currants, blueberries and other soft fruit.

The investment required for this kind of cultivation is high. A new glasshouse can cost a million euros (C$1.37 million) per hectare. Setting up a tabletop system can cost 100,000 to 125,000 euros (C$137,000 to $171,000). Even a field system can cost 25,000 to 30,000 euros (C$31,000 to $43,000). While the Dutch seem to be able to compete in the European export market based on premium fruit quality and high yields, it’s still not clear if this is feasible for Canadian growers.

“Greenhouse growers are trying to produce out of season, primarily earlier, to capture better prices,” explains Mark Sweeney, berry extension specialist with the B.C. Ministry of Agriculture. “I am not really sure there is a future in this. Overhead is very high, and with California at our doorstep, pricing may not justify the expense.”

In the Fraser Valley, more fruit growers are putting tunnels over their crop to protect late harvested crops from rain, and to some extent, extend the season and increase yield and quality.

“Late crops often command the best prices,” says Sweeney. “There are also some growers trying to get their crops a bit earlier, but this is often not desirable, as early pricing is not often better. I think we will see modest growth in tunnel production, but never to the extent that it is in Europe.”