Project explores innovative approaches for the detection of apple scab disease

The UK Agri-Tech Centre conducted a feasibility study with Kent fruit growers, Rumwood Green, and crop protection advisers, Landseer Ltd., on the project – ‘Apple Orchard Health: Evaluating Hyperspectral Imagery for Disease Detection and Biostimulant Efficacy’ – with funding from the Department for Environment, Food and Rural Affairs (DEFRA) and UKRI Transforming Food Production Challenge.

UK fruit growers are facing a major challenge, exacerbated by the diminishing availability of plant protection products (PPPs) controlling crop disease.

The phasing out of traditional PPPs, driven by environmental concerns, has added complexity to this issue. Despite utilisation of PPPs, UK apple growers experience an annual crop loss of approximately 10-12% due to apple scab, a fungal disease.

Without PPPs, this figure would skyrocket to 70-80%. However, there is a promising solution on the horizon by using biostimulants. These are natural substances or micro-organisms that can enhance the natural defences and overall health of the plants when applied to them.

One significant challenge of biostimulants is assessing their effectiveness as they operate distinctively from conventional PPPs.

Biostimulants serve as preventative measures rather than curative, necessitating timely application before visible disease symptoms emerge.

Accurately timing their use is difficult, as the critical phase of scab infection remains invisible to the naked eye.

The project aim was to address the challenge of evaluating the effectiveness of biostimulants, and timing their usage, by utilising advanced technologies such as hyperspectral cameras and drones.

Hyperspectral sensors can capture and analyse a wide range of frequencies of light very finely, which is like being able to accurately identify and measure hundreds of colours outside of what the human eye can see.

This provides detailed and precise characterisation of objects or materials based on the unique way they reflect light, as a spectral fingerprint.

By identifying these unique spectral fingerprints for crop diseases, like apple scab, and also determining which can indicate the efficacy of biostimulants, in future we can develop an affordable camera for growers to be able to detect these fingerprints.

This camera will serve as an early warning system, helping prevent disease spread, enhancing crop yield and operational efficiency, and reducing reliance on traditional PPPs.

Eliot Dixon, Head of Robotics and AI at the UK Agri-Tech Centre, said: “This was a fast-paced proof of concept project designed to provide evidence for both the efficacy of bio stimulant in apple scab control, but also in spectral imaging as a method for detecting apple scab.

“For the UK Agri-Tech Centre, this project highlights how our spectral imaging capabilities can be used in product development for both remote sensing and plant protection products.

“We are very pleased to have successfully shown how lab-based spectral imaging can be successfully transferred to a commercial farm.”

Michael Parker, Coldstore and Compliance Manager at Rumwood Green Farm Ltd, said: “This trial has been very challenging to reproduce results in the field similar to previous in-lab testing of detecting early signs of scab using specific wavelengths.

“Despite the challenges, we are a step closer towards early scab detection using the hyperspectral camera.

“The positive results shown of the biostimulant used will hopefully encourage more growers to use biostimulants as part of their scab control, not only relying on conventional pesticide programs.”

Stephen Tully, Director at Landseer, said: “With disease control becoming increasingly challenging due to changes in plant protection regulations and unpredictable weather, this project aimed to validate the efficacy of biostimulants to support their routine use and investigate the feasibility of an affordable early detection system for apple scab.

“This feasibility study has delivered encouraging results, demonstrating the effectiveness of biostimulants for integration into disease management programs and providing promising results for the development of an affordable early warning system for apple scab.”

Landseer Ltd. will be in attendance at the National Fruit Show on Wednesday 6 November at the Kent Showground (stand M77) to showcase the results from their trials, which were based at Rumwood Green Farm’s Ivy House Farm in Kent on approximately 1 ha of land.