In a ground-breaking demonstration, Roots Sustainable Agricultural Technologies Ltd, an Israel-based agricultural tech company, substantially increased tomato plant yields in Spain, using its patented Root Zone Temperature Optimisation (RZTO) heating system.

The demonstration, which was conducted in greenhouses in Almeria from December 2018 to March 2019, resulted in a 19% greater total plant yield, as compared with the unheated control crops.

As tomatoes are sensitive to frost and cold stress throughout the growing cycle, Roots' RZTO heating technology maintained crop root temperatures at a relatively stable range around 21° C ( about 70° F), despite ambient air temperatures in the greenhouse frequently dropping ten degrees cooler.

Without the use of this system, the zone temperatures of the control group's tomato plants' roots fluctuated between 10° and 22° C (about 50-72° F) over the same period.

The technology employed for the demonstration was developed to optimize plant physiology for increased growth, productivity, and quality by stabilizing the plant’s root zone temperature, says the company.

According to Roots, the benefits of stabilizing root temperatures are considerable - doing so to tomato plants throughout winter, for example, increases the absorption of water and fertilizers, which in turn improves the flowering and quality of the fruit.

It adds that the Roots system allows farmers to activate and monitor the system in real time through the cloud.

The significance of such a demonstration can hardly be overlooked - in 2016, 177 million tons of tomatoes were grown globally, a rise of 30% in a decade.

This production covers approximately 5 million hectares with an average yield of 3.7 kilograms (kg) of tomatoes harvested per square meter. However, in Spain, the yield is 8.62 kg per square meter - more than double the global average.

The main regions for fresh tomato production and export in the nation are Almeria and Murcia. Almeria, in particular, is characterized by small-scale family farms where cultivation is mostly in ‘enarenado’.

With this type of cultivation, a 30-centimeter-tall (cm) layer of soil is laid on top of the natural soil, followed by a 2- to 3-cm-tall layer of organic compost, and a 10-cm-tall top layer of sand.

Yet the success of Roots' heating system shows the potential for technological advances to change growing approaches.

Remarking on the current demonstration, the company's CEO Dr. Sharon Devir says, “We are very excited by the fact that our RZTO technology caused a significant yield increase on Spanish tomato crops."

Outlining how such progress could positively impact the market, she notes: "In addition to lost revenue from damaged plants, cold stress can injure both the above and below ground plant tissues, reducing crop quality and delaying the maturation of plants. Despite being grown in greenhouses with added soil protections, traditional growing and heating methods in Spain haven’t been able to mitigate significant overnight drops in temperature.

By using RZTO to heat the roots of tomato plants during autumn and winter, the farmer was able to mitigate the impact of cold stress and injury. Root zone heating ensures the roots' crop remains at optimal temperatures throughout the growing season, resulting in healthier crops and increased produce during the off-season.”