This trial and cultivation strategy reflect the practices implemented specifically at Ceickor in Querétaro, Mexico, based on local climate conditions, grower objectives, and technical guidelines used in the region. While Grodan’s 6-phase cultivation model provides general principles for stone wool crop management, growers in other countries may adapt the system differently depending on greenhouse technology, climate, and production goals.
Trial Observations:
- The local climate conditions did not negatively affect substrate management.
- The use of stone wool as a substrate in tomato cultivation allowed for an appropriate balance between growth stages.
- The inert structure of stone wool prevented root diseases, ensuring healthy crop development.
- Monitoring the root zone and using stone wool enabled a more efficient irrigation strategy, ensuring responsible management of water and fertilizers—ultimately enhancing crop productivity.
Phase 1: Transplanting and Rooting
Grodan, a global leader in stone wool substrates, in collaboration with Ceickor, a prominent educational institution in Querétaro, Mexico, conducted a trial to implement Grodan’s 6-phase stone wool cultivation system.
This first phase was successfully initiated by the team led by Engineer Abril Rangel, head of Ceickor’s research greenhouses.
Before transplanting began, several preparatory steps were taken: disinfection of the cultivation area, placement of slabs and drippers, and initial saturation. The blocks, which arrived pre-hydrated, were fitted with two drippers each. Saturation with nutrient solution was also carried out to ensure optimal plant development.
During this phase, cluster tomatoes (TOV – round type), consisting of two grafted plant varieties labeled 1043 and 1044 and provided by Bayer, were transplanted. Once the blocks were placed on the slabs, two drain holes were made at the slab corners, following the natural slope, to allow excess water to exit—critical for maintaining proper water balance.
The integration of GroSens sensors into the system enabled real-time, precise, and practical monitoring of water content (%WC), stability from start to end, slab temperature (T°)—which indicates whether the root system is active or possibly affected by pathogens—and electrical conductivity (EC), key factors for making informed decisions on irrigation strategies that support optimal crop development.
The primary objective of this system is to demonstrate that Grodan’s stone wool slabs can achieve higher yields through superior control, precision, and balance compared to other substrates commonly used in Mexico. This contributes to more efficient resource management throughout the growing process.
Phase 1 concludes once plant roots penetrate the slab, marking the start of the next stage in Grodan’s 6-phase system.
Phase 2: Rooting and Plant Development
Four weeks have passed since transplanting, placing us in Phase 2 of Grodan’s 6-phase system. Vegetative development has been balanced, and root penetration from the cube into the slab has been successful. This root development enables better nutrient uptake, crucial for the productive stages to come.
GroSens sensors installed during Phase 1 continued to aid in monitoring root behavior. Irrigation and nutrition decisions were made to guide the crop toward a balanced vegetative/generative state, maximizing its productive potential throughout the cycle. In this phase, the main objective was to reduce water content and increase EC in the substrate to promote deeper and more extensive root expansion along the slab.
Flowering continued, and the first set fruits were observed. The plants developed strong, robust stems—ideal for a successful production phase. Key strategies included irrigation based on radiation (watts and joules/m²) and daily %WC control. Supporting activities included applying sulfur to the ground cover to prevent pathogens, using biological control, and pollination through Koppert methods.
Phase 2 concludes when fruit load begins to increase.
Phase 3: Growth and Balance
Phase 3 of the trial focused on maintaining the quality of developing clusters and root activity, resulting in strong, balanced heads thanks to proper electrical conductivity (EC), which supported consistent fruit set and growth.
Another important strategy was reducing nighttime irrigation, which helps regulate plant activity during the day. A key element was maintaining stable water content and EC levels. In some sections of the crop, variety 1044 showed signs of ripening clusters, allowing for fruit unloading and promoting the development of new fruits, improving the overall maturity cycle.
Growth remained constant and uniform thanks to controlled irrigation tailored to plant needs and supported by appropriate nutrition. Irrigation start and end times were adjusted, especially on cloudy days, to optimize performance. During this stage, the plant must remain balanced until the first harvest.
Phase 3 ends with the first harvest.
Phase 4: Production and Balance
In Phase 4, the first harvest took place. One of the main strategies was to support increased plant transpiration and maintain the slab water content between 55%–65%. It was also essential not to overly reduce water content during the night-to-morning transition to preserve growth, vigor, and fruit weight.
Root zone management was adapted between cloudy and high-radiation days to encourage optimal crop performance. Irrigation start times were aligned with light accumulation (J/cm²) and/or light intensity (W/m²) to ensure proper water levels throughout the day.
Thanks to the Next Generation (NG2.0) fiber technology in the blocks and slabs, which allows the root system to thrive with fewer resources, EC control was maintained—even with minimal drainage and shorter irrigation periods—preserving root health as the crop regrew after early harvests.
Phase 4 ends once production levels stabilize.
Phase 5: Peak Production
By Phase 5 of Grodan’s 6-phase model, normal production levels were reached—approximately 7 kg/m² after five weeks of harvest.
This phase was marked by well-established root penetration into the slab, supporting fruit quality even under unstable weather conditions such as cloudy days and high light intensity.
Water content and EC levels remained stable, with adjustments made to optimize water absorption and maximize plant cooling potential.
The third and fourth clusters were harvested during this phase, aligning with flowering to keep fruit load and quality stable.
Phase 5 concludes with the setting of the final fruit.
Phase 6: Final Production
Phase 6, the final stage of the trial at Ceickor, began when the plant growth point was pruned. Maintaining a healthy and active root system was essential to ensure nutrient availability remained balanced.
With shorter days and reduced light intensity, irrigation strategies were adjusted to compensate for rapid transpiration changes and to gradually reduce water content at night.
Significant observations included healthy roots in multiple slabs, vigorous foliage, and fully set final clusters.
As water content decreased gradually, EC levels were increased to maintain balance.
Phase 6 ends with the final harvest.
