Season Farms is a four hectare operation located in Gordonton, in the Waikato region of New Zealand. The farm grows strawberries, raspberries, passionfruit, figs and fruit trees in greenhouses.
Guillermo DiGiuseppe is the agronomist and crop manager at Season Farms. During summer months he noticed the high temperatures were having a negative impact on production and investigated further.
Although air temperature was being monitored, air temperature is only a proxy for plant temperature, and an approximate one at that. In some cases the difference between the two can be as much
as 7°C. Guillermo noted:
“Many sensors only provide an approximation of plant temperature, they can’t tell you the actual plant temperature. We see a clear difference between air temperature and the temperature of the strawberry leaf. It would be better to have a temperature sensor on the leaf rather than a general air sensor”.
So using an infrared thermometer, he measured leaf temperatures of several plants over the course of a typical summer day. He discovered these temperatures were getting up to as high as 35°C, resulting in overly stressed plants.
Plants experiencing high temperatures close their stomata to conserve water, but by doing so sacrifice their ability to cool themselves through water evaporation. Thus, extreme plant temperatures reduce the productivity of the plant.
This information provided a strong business case for the farm to implement whitewashing of the greenhouses. This method is commonly used to reduce heat and light during the hotter summer months. The whitewashing was conducted shortly after Guillermo’s discovery.
The solution came in the form of FarmRoad sensors. Six sensor units were deployed after the whitewashing implementation to monitor the plant temperature and radiation levels, both inside and outside. The FarmRoad unit's external plant temperature sensor coupled with its built-in PAR and RAD sensors meant that everything Guillermo needed to track was monitored continuously. Most growers capture light readings from sensors outside of the greenhouse. Having light sensors inside enables the grower to observe how much light loss can be attributed to their glass, plastic or whitewash.
Using the data provided by the FarmRoad sensors, the farm was able to conclude that the implementation of the whitewash had increased production by 20-30% and an increase in strawberry fruit size. Moreover, FarmRoad was able to show the reduction in radiation light by comparing the inside radiation with the outside radiation. (Fig. 1) It also showed that plant temperature barely exceeded 30°C throughout the hottest summer period, a positive outcome of their solutioning. (Fig. 2)
These two metrics combined with the production increase, proved the value of the whitewashing and validated their decision to invest.
Moving forward from the business case analysis of whitewash, Guillermo sees other benefits of using FarmRoad. Due to changing climate/seasonal temperatures, Season Farms want to dial in the timing of whitewash application – in future it may be pushed earlier or later, depending on what the plant data reveals.
Being able to monitor the metrics of air temperature, inside radiation and plant temperature will provide these insights for a timely application. The team at Season Farms are confident that FarmRoad will continue to help them improve crop productivity.