More sleep for growers

Renningen and Weinstadt, Germany – For the grower Martin Bauer, it was not that long ago that strawberry season meant one thing: sleepless nights. Between mid-March and late May, when the plants flower, he would have to work ten to fifteen night shifts. Fearing that his strawberry plants could fall victim sub-zero temperatures at night, he would drive out to his fields around the German town of Weinstadt, near Stuttgart. If a check of air temperature revealed it was zero degrees Celsius or colder, he would cover the long rows of strawberries with fleece. “Frost would ruin everything,” Bauer says. He knows what he is talking about: losing 50 to 70 percent of his entire strawberry crop every two to three years used to be a fact of life – posing a serious threat to his livelihood.

However, Bauer no longer has to worry. On six of his twelve fields, a Bosch sensor system now monitors the condition of his strawberry plants. “The app that comes with the system lets me check on my plants from home – while sitting comfortably on my couch or under the bedclothes, so I don’t disturb my wife’s sleep,” Bauer says. “This doesn’t only make life easier for me. In the old days, 20 helpers used to have to regularly drive out to the fields with me at night.” Lessons learned from the six fields equipped with sensors can be applied to the other six; Bauer selected the fields with local climatic fluctuations in mind.

Sensor system measures temperature and humidity

The sensor system is the brainchild of the Deepfield Robotics, a Bosch start-up. The sensors measure the amount of moisture in the soil and inform the grower if it is too dry. They also measure air temperature and humidity and use that in order to calculate wet-bulb temperature. “If this temperature is zero degrees Celsius or below when the plants are beginning to flower, the grower has to cover the plants or take other steps to protect them from frost,” says Christian Glunk from Deepfield Robotics. The grower is also informed if the plants are too warm. Growers themselves can set the threshold values that will trigger an alert. In that case, growers can remove the coverings to ensure the sensitive plants are properly ventilated. And by tracking temperature and humidity records, growers can check whether everything is progressing smoothly or if there is a risk of mildew. “None of this requires any manual measurements,” Glunk says.

What’s more, the system can be used for other plants. Fruit growers could also use the sensors to monitor the development and growth of currants or raspberries. For Martin Bauer, this is a tempting idea – after all, he grows raspberries, too.