Vijay Rapaka, Ph.D. Manager, Corporate Research and Technical Support Manager, Smithers-Oasis Company, Kent, OH
Brenton Williams, Greenhouse Research Technician, Smithers-Oasis Company, Kent, OH
Devyn Rothbrust, Greenhouse Research Technician, Smithers-Oasis Company, Kent, OH
A new OASIS® Horticubes® hydroponic propagation medium with enhanced biodegradability.
A case study with spinach, cilantro and kale.
The key for successful hydroponic production is to start with a strong young plant. Propagating in engineered media ensures uniform germination and growth without any concerns for plant diseases and food safety. OASIS® Grower Solutions has brought the most successful and reliable hydroponic propagation media to the hydroponic industry viz., Horticubes® and later Horticubes® XL, which are exclusively engineered for commercial hydroponic production. Over the last few years, hydroponic local food production has been significantly increasing because of the change in food habits, desire for consuming fresh produce, and to mitigate food safety related issues. Furthermore, hydroponic local food production has the solution to improve environmental sustainability and reduce the carbon foot. OASIS® Grower Solutions, which is committed to grower success as well as environmental sustainability, has developed an engineered hydroponic media, Horticubes® eS, which has enhanced biodegradable properties without affecting the plant growth performance. Horticubes® eS foam has been shown by ASTM D5511 to biodegrade 75% within 335 days in a biologically active landfill condition.
The objective of this following experiment is to determine the plant growth performance in Horticubes® eS medium and to compare against the growth performance in Horticubes® and Horticubes® XL Medium.
Materials and Methods
The trials were conducted during August/September of 2016 with Horticubes®, Horticubes® XL and Horticubes® eS foam medium with three different types of crops: spinach ‘Carmel’, cilantro ‘Santo’, and kale ‘Red Russian’. With all the three types of foam media, 276 count sheets with multi seed dibble hole were used. The foam sheets were placed in a carrying tray with drain holes and watered by float saturated followed by complete overhead leaching with 1 mS/cm (125 ppm N) of OHF 16-4-17 using a hose and a breaker. Note: Initial watering with fertilizer is extremely important for uniform growth. Using complete nutrient solution at 1 mS/cm (125 ppm N) instead of clear water with initial watering (that includes both float saturation and overhead leaching) will double the seedling growth. For detailed information on initial watering, please refer to the protocol sheet. Following initial watering, multiple seeds were placed per dibble hole. All crops were then covered with vermiculite.
Note: Previous trials indicated that covering with vermiculite significantly improves uniformity in germination, faster growth, and minimizes seedling pushing out of the media in the case of spinach, cilantro, and kale.
Propagation: After initial watering and seeding, the sheets were placed in a greenhouse and the first two days were not watered. On day three and day four, the sheets were misted and after that watered once a day or as required using a hose and a breaker with 1 mS/cm (125 ppm N) of OHF 16-4-17 as required. For further information, refer to the protocol sheet.
Greenhouse conditions: The day time heating and venting set points are 65°F and 75°F (18°C to 26°C), respectively. The night time heating and venting set points are 55°F to 65°F (12.5°C to 18°C), respectively. A 16h day length was provided using HPS lighting and DLI was targeted around 17 to 18 moles/day. When light levels exceed 500-600 μ. moles/m2/s greenhouse was covered with shade curtains. Greenhouse relative humidity was maintained between 50% and 60%.
Observations: Photographs were taken on day 7 with kale and day 14 with spinach and cilantro. The fresh weights were recorded by harvesting at the foam surface level.
In the case of spinach and kale, the seedling growth at 14 days after seeding was similar in all three types of media. In the case of cilantro, the seedling growth was significantly higher in the case of Horticubes® XL and Horticubes® eS compared to Horticubes® foam.
In general, the plant growth performance in the brand new foam technology with enhanced biodegradability, Horticubes® eS, is similar or superior when compared with the growth performance in Horticubes® and Horticubes® XL foam medium.