Learning #1: Crucial to find the right balance between light, temperature, and yield
Growing successfully indoors is all about finding the right balance between light, temperature, and yield. Increasing the light intensities might increase the yield, but that does not happen linearly. In The GrowWise Center we can achieve up to 1200 µmol/s/m2, but plants do not use all that light equally efficient. With the Philips GrowWise control system we can optimize the light intensity to the needs of the plant and seek the optimal point where the extra yield is worth more than the extra energy input from both the light and the climate system. Hence, we do not just focus on yield maximization, but rather try to achieve the most efficient system.
To steer the plant into the right balance between vegetative and generative growth it is important to adjust the temperature accordingly. Plants can be steered into a more generative state by increasing temperature. However, overcharging could result in too generative growth. The plants will put too much energy into the fruits and overload the plant, something that will cause a dip in production later on. Growing tomatoes is like walking a tight rope: correcting too fierce when in danger of falling off one side could result in falling off the other side. In a perfect strategy, only small adjustments are needed to keep the plants well balanced. Something that is undoubtedly easier without the variable influences of the climate outside.
The trial also helped us to better understand the partitioning of energy between the heat load from the LEDs and the transpired moisture from the plants. This allows us to go beyond the optimal light-use efficiency, and rather improve the total system efficiency.
Learning #2: Strong business case in place for growing high wire tomatoes in an indoor farm
Not all tomato varieties are suitable to grow in an indoor farm and not all are of interest for this form of high-tech cultivation. Some varieties are difficult to grow in a conventional system, but they might flourish in an environment with less prevalence of disease and a more stable climate. In theory, the highest production numbers could be reached with big truss and beef tomatoes, but these are certainly not suited for every market. Lower producing cherry and cocktail tomatoes or difficult to grow ‘Coeur de Boeuf’ are usually full of taste and visually appealing and therefore can serve high-end retailers or restaurant chefs.
Learning #3: Growing the right varieties can minimize handling and labor costs
In the trials we have successfully grown over 20 cherry and cocktail varieties to select the best performing, best tasting and most robust varieties that require very little handling and pruning. This makes them ideal for vertical farmers who may not have a lot of experience in growing a certain variety of tomato and the reduced labor costs will increase the city farm’s profitability.
Learning #4: Endless potential to steer plant growth in indoor cultivation
An important benefit inherent to indoor cultivation is that we have control over plant growth. The right light spectrum, optimal light intensities, temperatures, and CO2 levels enable you to achieve an excellent balance of fruit load and vegetative plant growth. Having control over all these growth parameters means that we can really optimize for both production and taste. Moreover, the growth recipes we have developed are reproducible. This creates a consistent cultivation environment that allows reliable yield prediction. It gives growers more flexibility and security over their production and enables them to steer yields to meet market demands. In addition, creating the right environment also provides the potential to actively steer specific characteristics, such as sugar content, acidity, vitamins, and other compounds, to meet preferences for taste and nutritional value, respectively.
Learning #5: Tomatoes can now also be grown in challenging markets
Building a farm in an area that already has plenty of greenhouse or open field production would, of course, not be very profitable. Yet, there are many places where locally grown tomatoes are not available all year-round because of the harsh climate or other factors. A farm in the Middle East for example makes perfect sense: lots of water can be saved and the close proximity to the consumer means that the product can be super fresh and of high quality. Our trials show that it is possible to grow fresh, tasty tomatoes in an indoor, climate-controlled facility year-round, without the use of pesticides.
Blueprint for high wire tomatoes in a vertical farm
Based on the results of the trials, we now have a blueprint for growing great tasting high-wire tomatoes in a city farm with a fully controllable environment. That opens up new opportunities to grow fresh tomatoes year-round in extremely hot and cold climates. We can advise growers on how to set up their system, and how to choose the best variety based on their customers and market. With the research baseline in place, we can now focus on trials for specific concepts and markets.
Please learn about our Philips GrowWise Center or read our other blogs on growing tomatoes.