Cooling technology increases lettuce yield

Roots Sustainable Agricultural Technologies has released results from a successful pilot on Romaine lettuce — these show a 132% increase in lettuce leaf fresh weight using the company’s proprietary Root Zone Temperature Optimisation (RZTO) cooling technology.

Impressively, the lettuce growing cycle was reduced by almost half, with the crop ready for harvesting in 27 days.

This follows on from successful RZTO cooling proof of concepts on lettuce using Nutrient Film Technique (NFT) technologies and interim results in medicinal cannabis.

The Romaine lettuce pilot was conducted during the Israeli summer over 27 days between July and August this year, at ROO’s research site in central Israel. Using the hybrid ground source heat exchange version of the RZTO system, lettuce roots were cooled to remain relatively stable around 24°C, despite air temperatures in the greenhouse regularly topping 34°. In comparison, roots of control plantings fluctuated between 28° and 34°.

Cooled lettuce plants had an average fresh weight of 502 grams, compared to an average weight of 216 grams for non-cooled plants. On top of that, marketing weight was achieved in 27 days — compared to seed manufacturer data showing a normal growing cycle range of 30–50 days.

ROO is the only company with commercial root zone cooling technology — something that gives it a distinct edge in the flourishing ag-tech space.

Its RZTO technology optimises plant physiology for increased growth, productivity and quality by stabilising the plant’s root zone temperature.

Roots CEO Dr Sharon Devir said that these results highlight the many benefits of root zone cooling in modern agriculture — including enhanced plant growth, improved quality, shorter growing cycles and greater growth uniformity, as well as energy savings compared with traditional greenhouse cooling systems.

“Cooling the roots of lettuce plants in summer not only significantly increases crop yield but also reduces the growing cycle duration and increase yield uniformity,” Devir said. “These benefits together could help farmers plan for increased annual crop production and, therefore, increased income.

“This latest pilot complements the pilot reported in July where Root’s RZTO technology was used in collaboration with NFT technologies created by Teshuva Agricultural Projects to cool the nutrient temperature of hydroponically grown lettuce. The results are consistent with previous open field lettuce cooling experiments.

“Our RZTO systems are versatile and can be used to cool the roots of crops in open fields, grow bags, hydroponic and in soil.

“Our RZTO cooling systems have so far been effective in stabilising the plant roots of basil, apricots and medicinal cannabis,” Devir added. “We are the only company in the world with a commercial root cooling technology. We are therefore optimistic about our ability to generate increased sales, as the results of these pilots conducted in areas that experience weather extremes are analysed by farmers in various markets.”

Earlier this month, ROO was granted a divisional patent for its disruptive Irrigation by Condensation (IBC) technology in India — where erratic rainfall and water scarcity has affected food production. ROO’s IBC system allows farmers to produce food crops using irrigation sourced only from humidity in the air.

Originally published here.