Visual feedback of the plant structure is too slow for real-time optimization of the growing climate. Gardin measures photosynthesis, the most fundamental physiological process in the plant that is directly related to the assimilation of sugars for growth says Julian Godding, Lead data scientist at Gardin, a UK agritech.

Measuring photosynthesis in growing environments Growers are constantly trying to understand how the environment affects their plants and respond quickly to mitigate variability and achieve production targets. However, visual feedback from plants is slow - taking days or even weeks to materialize. This severely limits the potential for data-driven growing since several variables may impact the crop within that period. Chlorophyll fluorescence monitors the photosynthetic activity of the plant and is a powerful technique that has been used in plant research for decades.

However, deployment in commercial farms has been limited because of high costs, a lack of automation and a gap in technical knowledge. It is well known that photosynthesis is the fundamental process in plant growth, making the technique a good indicator of how the growing environment is impacting plant productivity. Gardins novel chlorophyll fluorescence sensor is designed for use in commercial farms. It uses advanced optical engineering to autonomously measure hundreds of plants throughout the day and employs algorithms to deliver interpretable insights to growers.

Real-time plant feedback Over the past two years, Gardin has been undertaking research funded by InnovateUK in partnership with the Advanced Plant Centre, hosted at the James Hutton Institute, and Intelligent Growth Solutions. The project explored the potential for chlorophyll fluorescence to be used as a technique for plant-driven optimization in CEA.

Whether due to the outdoor climate in a greenhouse or the impact of microclimates in indoor farms, growth environments for food production are constantly changing. Small changes in temperature and humidity can have a significant impact on plant outcomes, affecting yield and quality; and making it harder for growers to meet their targets Tevan et al, 2021 - The left side image shows an RGB capture of the plant canopy, right side image shows a thermal capture of the same plants. The brighter color indicates a higher temperature.

For the first time, Gardins sensors have enabled us to remotely explore plant activity in an industrial setting. This invention has been a significant milestone in our quest to optimize recipe development and is crucial for creating the optimal plant environment, says Csaba Hornyik, Senior Plant Scientist at Intelligent Growth Solutions.

Until now, growers could not measure the effect of the climate on plant physiology in real-time and at scale using cost-effective sensors, instead having to rely on visual parameters such as height, with limited resolution and flexibility.

Gardin's technology gives growers access to quantified measurements of plant photosynthesis, enabling a new method of growing that uses plant-driven insights to achieve better results. Julian explains that in most other industries, there is an obsession with measuring product quality. However, in agriculture, growers often rely on indirect indicators like temperature and humidity, as plant physiology is hard to measure accurately at scale. Gardin aims to bridge this gap and establish a growth method based on direct feedback from the plants."

Moustakas et al, 2022

By linking the climate to the plants, Gardin aims to consolidate all environmental variables into simple plant insights that enable rapid optimization of the growing environment and validating this approach was one of the key aims of the research. To achieve this, the photosynthetic activity of several species was measured in a controlled indoor growth environment with artificial lighting.

More than fifty batches of plants were grown with different light intensities while maintaining the same overall climate but with the presence of microclimates. The fertigation strategy was adjusted at one point, and there were variations in germination density. This reflects the reality of production environments - continuous improvement was a great test for the ability of chlorophyll fluorescence to flexibly monitor plants under different conditions and clearly distinguish their photosynthetic performance.

The results showed Gardins measurements of photosynthetic efficiency correlating well with the fresh weight (kg/m2/annum) and productivity (kg/m2/kWh) of each batch of plants. In other words, Gardin's photosynthesis measurements could effectively explain 50% of the variability in productivity across hundreds of kilos of plant product using a simple metric that is generalizable for any cultivar. This capability to directly measure plant productivity is a step change in agriculture, accelerating the grower feedback loop from weeks to mere minutes. Moreover, Gardin's capacity to measure across a broad canopy area assures growers that they are optimizing their entire farm's productivity and quality.

In addition, the James Hutton Institute conducted a nutritional analysis to study the impact on food quality. In an exciting development, it was discovered that basil plants with lower stress levels, as measured by the Gardin sensor, had lower concentrations of estragole - a carcinogenic and genotoxic compound that causes an unfavorable aniseed taste.

These exciting findings underscore the significance of reducing plant stress events in growing environments to the benefit of consumers. The project is an elegant illustration of what can be achieved by using Gardins real-time metrics as an optimization parameter - were very excited to see more and more growers adopt them to improve the productivity of their farm. The James Hutton brings experience to the complex task of plant nutritional analysis and allowed us to make novel discoveries linking the growing environment to the nutritional content of leafy greens. notes Fabrizio Ticchiarelli, Lead Biologist at Gardin.

Plant driven growing Gardin Pulse is a farm management product designed for commercial growers. It serves as a tool for rapidly optimizing growing environments with confidence. Proprietary analytics provide instant insight into farm performance, visualizing the impact of a changing environment and enabling rapid testing of different climate strategies to achieve the best results. With energy prices currently a key concern of growers, Gardin Pulse offers a solution for growers to determine energy savings strategies with optimal lighting and heating control for the plants.

Julian Godding, Lead data scientist at Gardin will be presenting 'Plant Computer: the next generation of greenhouse cultivation' at the Startup Arena Hall 5.1 at the Fruit Logistica this week.

For more information: Gardin http://www.gardin.co.uk

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'From slow visual feedback to real-time plant physiology' - Verticalfarmdaily.com: global indoor farming news