Talk on Satellite-Based Crop Coefficients for Smarter Potato Irrigation by Prof M. Steyn

 

Precision Agriculture and Irrigation

How real-time satellite observations could help South African growers conserve water, reduce energy costs and protect potato yields

About the Speaker

Professor Martin Steyn of the University of Pretoria presented research on using satellite-derived crop coefficients to improve irrigation scheduling for potatoes under South African production conditions.

Professor Steyn was also the External Examiner for the MSc Agronomy programme at the Faculty of Agriculture, University of Mauritius. His visit provided an opportunity to share research insights with Faculty staff and strengthen academic engagement in precision agriculture and sustainable crop production.

Prof. Martin Steyn with the Programme Coordinator, Mr. M. Choonea and the Dean of the Faculty, Assoc prof J. Govinden Soulange.

Why Smarter Potato Irrigation Matters

Potatoes are an important South African crop, with approximately 50,000 hectares planted annually across 16 production regions. Around 85% of this area is irrigated, mainly using centre-pivot systems.

However, potatoes are temperate plants being produced in a generally water-scarce, semi-arid country. They are highly sensitive to water stress, which can quickly reduce both yield and tuber quality. Irrigation also carries substantial pumping and energy costs.

The central challenge: How can farmers apply enough water to protect yield and quality without wasting water or the energy required to pump it?

The conventional approach

Estimating Crop Water Use with a Standard Coefficient

Conventional irrigation scheduling commonly estimates crop evapotranspiration using the following relationship:

ET = ETo × Kc

ET = estimated crop evapotranspiration or crop water use

ETo = reference evapotranspiration calculated from local weather data

Kc = crop coefficient representing the crop’s growth stage and water demand

Standard crop coefficients, including those published in FAO-56 tables, are widely used. However, these coefficients are static averages based on an assumed crop-development pattern.

The actual coefficient can differ because canopy growth is influenced by planting date, variety, management, weather, soil conditions and crop stress. Fixed values can therefore result in either over-irrigation or under-irrigation.

The satellite alternative

Measuring the Crop Instead of Assuming Its Growth

The research investigated whether real-time crop coefficients could be estimated from satellite observations. The principal indicator was the Normalized Difference Vegetation Index, or NDVI, obtained from Sentinel-2 satellite imagery.

NDVI provides an indication of green vegetation and canopy development. As the potato canopy expands, the satellite records the change and allows researchers to calculate a dynamic crop coefficient known as Kc_NDVI or Kcb_NDVI.

ET = ETo × Kc_NDVI

Local weather demand multiplied by a crop coefficient derived from the crop’s observed canopy

The important difference is that the satellite coefficient responds to the crop that is actually growing in the field rather than following a predetermined growth curve.

From satellite to irrigation decision

How the System Works

Step 1

Observe the Canopy

Sentinel-2 satellite imagery is used to calculate NDVI and monitor the development and condition of the potato canopy.

Step 2

Calculate a Dynamic Coefficient

The vegetation index is converted into a crop coefficient that reflects the actual canopy rather than a standardised growth stage.

Step 3

Combine It with Weather Data

The satellite-derived coefficient is multiplied by reference evapotranspiration obtained from a local automatic weather station.

Step 4

Recommend an Irrigation Amount

The estimated crop water use can be translated into a practical irrigation recommendation for the grower.

Field validation

Testing the Method in Commercial Potato Fields

The research team monitored seven potato fields in South Africa’s Sandveld production region. The study collected information on:

• Weather conditions
• Irrigation applications
• Drainage and soil-water content
• Canopy cover and fractional interception
• Satellite vegetation indices
• Actual crop evapotranspiration

Installed equipment to measure: Weather data, Irrigation, Drainage and Soil water content 

Canopy cover and fractional interception of photosynthetically active radiation were measured approximately every 10–15 days. Eddy-covariance systems were installed in three fields to obtain direct measurements of actual evapotranspiration.

Three methods were compared

1. Standard FAO-56 crop coefficients

2. Crop coefficients derived from satellite NDVI

3. Actual ET measured through eddy covariance

Research findings

What Did the Researchers Find?

Satellite NDVI Followed Canopy Development

NDVI tracked changes in canopy cover and the fractional interception of photosynthetically active radiation effectively.

Satellite Coefficients Agreed with Measured ET

For most of the growing season, the NDVI-derived crop coefficients correlated closely with coefficients calculated from eddy-covariance measurements.

Early-Season Accuracy Was Weaker

Before the canopy completely covered the ground, evaporation from exposed soil represented an important part of total water loss. Canopy NDVI alone could not capture this component as accurately.

Dynamic Coefficients Reflected Actual Field Conditions

Unlike fixed coefficients, the satellite values responded to differences in canopy growth, crop condition and field management.

From research to farm

Testing GeoIrrigation at Commercial Scale

The concept was developed further through collaboration with GeoTerraImage. A GeoIrrigation service based on the Kcb_NDVI approach was tested on approximately 300 hectares of commercial potato fields during the 2025/26 production season.

The service converted satellite observations and local weather data into daily irrigation recommendations, which were delivered to participating growers by email. The early commercial-scale results were described as promising.

Practical significance

Satellite information becomes valuable to farmers when it is converted into a clear operational recommendation: how much water should be applied, and when?

Potential Benefits for Growers

More efficient water use: Irrigation can be matched more closely to actual crop demand.

Lower pumping costs: Avoiding unnecessary irrigation can reduce energy consumption.

Protection of yield and quality: Improved timing may help prevent damaging periods of water stress.

Field-specific management: Recommendations reflect differences between individual fields rather than relying entirely on regional averages.

Remaining Limitations

Although the results are encouraging, the system still faces several technical challenges.

Cloud cover: Persistent cloud can delay the acquisition of usable satellite imagery.

Early crop development: NDVI is less reliable when the canopy is incomplete and soil evaporation forms a large share of total water loss.

Local validation: Relationships between NDVI and crop coefficients may require calibration for different crops, regions and production systems.

A Practical Step Towards Precision Irrigation

Satellite-derived crop coefficients provide a practical opportunity to replace generalised assumptions with field-specific information on actual canopy development.

When combined with local weather-station data, these coefficients can help growers match irrigation more closely to crop water demand. This could conserve water, lower pumping costs and support more sustainable potato production in water-scarce environments.

Continued refinement of early-season estimates, improved management of cloud-related data gaps and wider commercial testing will determine how rapidly services such as GeoIrrigation can be adopted across South Africa and comparable production regions.

Could satellite-based irrigation recommendations become a standard tool for farmers in water-scarce regions?

Visit of Scholars from the University Slavonski Brod, Croatia - Under the Erasmus+ Staff Exchange Program

 

 

Agriculture, Science and Innovation

Visit of Scholars from the University Slavonski Brod, Croatia

Assist. Prof. Nataša Romanjek Fajdetić, Ph.D. and Assoc. Prof. Mihaela Blažinkov, Ph.D. visited the Faculty of Agriculture, where they met colleagues, exchanged knowledge and experiences, and learned more about the Faculty’s teaching and research activities. On 2 October 2026, they gave a talk to the Faculty’s staff and students, providing an opportunity to share their expertise and discuss areas of common academic interest and potential future collaboration. A brief overview of the discussion is provided below.

Beyond the Game of Thrones Coastline
When most travellers picture Croatia, their minds instantly drift to the dazzling Adriatic coast. With more than 1,000 islands, crystal-clear waters and historic stone cities such as Dubrovnik—made world-famous as a major filming location for Game of Thrones—it is easy to understand why tourism is a central pillar of the country’s economy.

However, reducing this vibrant Southeast European nation to its sun-drenched resorts overlooks a far more compelling story.

Home to fewer than four million people, Croatia combines remarkable agricultural diversity, a history of influential inventions and forward-looking biotechnical research.

Discovery 01

Croatian Scientists Are Producing “Thunderstorm Water” to Strengthen Crops

Researchers from Croatian biotechnical departments are investigating methods of improving crop resilience through applied physics. One of these methods involves plasma-activated water, or PAW.

The process treats water with cold plasma, producing chemical reactions similar to those occurring naturally during thunderstorms. Lightning can enrich rainwater with reactive nitrogen compounds and hydrogen peroxide, which may influence plant growth and stress responses.

The Croatian Professors with  the Dean of the Faculty of Agriculture, Assoc Prof J.Govinden Soulange and the HoD AFS, Dr D. Ramful Baboolall

How the experiment worked

Lettuce was irrigated with plasma-activated water in outdoor plots and controlled greenhouse conditions. The greenhouse reached temperatures approximately 10°C higher than those recorded outdoors.

 Prof. Nataša Romanjek Fajdetić

The greenhouse lettuce treated with PAW developed higher concentrations of proline. This amino acid acts as a natural osmoprotectant, helping plants cope with heat, water loss and other forms of environmental stress.

Click here for the full paper

“The lettuce grown in the greenhouse had a higher content of proline. Proline protects the plant—it helps the plant fight stress.”

Prof Mihaela Blažinkov

The work has already contributed to four A1-category scientific papers. The researchers are now examining how drought affects secondary metabolites in medicinal plants such as sage, chamomile and lavender.

Discovery 02

From the Cravat to Electric Supercars

Despite its modest population, Croatia has a rich tradition of innovation spanning fashion, aviation, electrical engineering and modern transport.

The Necktie

The modern necktie developed from the distinctive cloth worn around the necks of Croatian soldiers. The word cravat is itself derived from the name given to the Croats.

The Parachute

Renaissance-era Croatian ingenuity contributed to early concepts and functional designs that influenced the development of the modern parachute.

Nikola Tesla’s Croatian Roots

Nikola Tesla was born in what is now Croatia. His extensive body of work helped establish modern alternating-current power systems and transformed electrical engineering.

Electric Supercars

Croatia’s inventive culture continues through a new generation of engineers developing record-breaking, high-performance electric vehicles.

Discovery 03

The “Green Part” Feeds the “Blue Part”

Croatia depends on a complementary relationship between its coastal and continental regions. The Adriatic “blue part” attracts international tourists, while the inland “green part” supplies much of the agricultural produce required to sustain the tourism economy.

The boomerang-shaped region of Slavonia, situated in the eastern continental interior, is one of Croatia’s principal agricultural areas. Its fertile plains support the production of cereals, fruits, vegetables, wine and livestock products.

Agriculture and tourism are interconnected

Slavonia’s farms form part of the domestic supply chain that feeds Croatia’s residents and the millions of visitors arriving on the coast each summer.

The region is also known for protected traditional products such as Kulen, a highly valued spicy cured-meat speciality closely associated with Slavonian food culture.

Interacting with the students

Discovery 04

The Green-Transition Challenge in Croatian Agriculture

Croatia’s transition towards more sustainable agriculture illustrates the practical tension that can arise between environmental objectives and day-to-day farming realities.

European restrictions on conventional pesticides encourage farmers to adopt lower-risk alternatives. However, biological crop-protection products frequently require preventive application, accurate timing and specialised technical knowledge.

Key takeaway

Environmental regulations must be accompanied by farmer training, effective extension services and affordable crop-protection alternatives. Without this support, the transition may create production difficulties, regulatory workarounds and continued reliance on food imports.

Certified organic production currently represents only a limited share of Croatia’s agricultural area, while the country continues to import a substantial proportion of its food. These conditions demonstrate that agricultural sustainability depends on practical support as well as regulatory ambition.

Discovery 05

The Quiet Excellence of Croatian Olive Oil and Wine

Although countries such as France and Italy dominate international headlines, Croatia produces highly regarded olive oils and wines. Because physical land availability is limited, many producers focus on boutique quality, regional identity and small-scale production rather than industrial volume.

Croatia possesses a remarkable combination of microclimates, soils and indigenous grape varieties. These conditions support distinctive wines whose characteristics are closely connected to their places of origin.

Olive-oil producers similarly rely on careful harvesting and small-batch pressing to produce high-quality extra-virgin olive oils, many of which have received international recognition.

“Maybe they say that our olive oil is the best in Europe. Some other countries could not say that. They are very jealous because we have very good oil.”

Small Nation, Big Impact

Croatia is more than a picturesque summer destination. It is a dynamic meeting point between agricultural tradition, scientific research, technical ingenuity and regional identity.

From plasma-activated irrigation water to centuries of influential inventions, Croatia demonstrates that a country’s physical size does not determine the scale of its contribution to the world.

What enables some small nations to become global powerhouses of groundbreaking ideas?

Ayurveda Day at the University of Mauritius Connecting Agriculture Health and Traditional Knowledge

 

One Health  |  Traditional knowledge  |  Public engagement

Healthy people depend on healthy food systems and a healthy environment. This connection gave particular relevance to the Faculty of Agriculture's celebration of Ayurveda Day at the University of Mauritius.

Held under the theme Ayurveda for a Healthier Tomorrow One Health One Future, the event brought together representatives from academia, government, healthcare and the Indian High Commission. It explored how traditional knowledge can contribute to contemporary health discussions while remaining connected to scientific investigation, quality education and responsible practice.

The celebration also marked the launch of an Ayurveda Information Corner at the University Library, creating a new resource for learning, research and public engagement.

Central message

Traditional knowledge should be preserved alongside rigorous research, ethical responsibility, reliable education and patient safety.

Scientific research can connect medicinal-plant knowledge with evidence, quality and safety

An agricultural perspective on One Health

The One Health approach connects human well-being with the health of animals, plants and the environment. For the Faculty of Agriculture, it provides a valuable framework for examining the relationship between food production, nutrition, biodiversity and public health.

Speakers highlighted Ayurveda's emphasis on balanced nutrition, daily routines, mental well-being and harmony with nature. These themes create opportunities for agricultural teaching and research to engage with broader questions. How can food systems support healthier diets? How can medicinal plants be studied and cultivated sustainably? How can local knowledge be documented while respecting the communities that preserve it?

The discussions encouraged collaboration across agriculture, food science, nutrition, medicine and biotechnology. Such collaboration could connect knowledge of plants and food production with research into their composition, quality, safety and potential uses.

Agricultural opportunities

• Sustainable cultivation and conservation of medicinal plants
• Research on the nutritional quality and safety of foods
• Study of how growing, harvesting and processing affect plant quality
• Public education linking food production, nutrition and health

Traditional knowledge and scientific responsibility

A strong emphasis across the speeches was the need for evidence. Traditional practices can provide questions and ideas for research, but their safety and effectiveness require careful evaluation.

For agriculture, this principle is particularly relevant to medicinal plants. Research opportunities extend from plant identification and cultivation to the influence of growing conditions, harvesting and processing on quality. These are possible areas of contribution for the Faculty, building on the event's call for interdisciplinary investigation.

Speakers also emphasised that research must respect the holders of traditional knowledge through appropriate consent, acknowledgement and fair arrangements. Preserving this knowledge therefore requires both scientific care and ethical responsibility.

Traditional knowledge can guide research questions, but health claims must still be assessed through reliable evidence.

Prevention nutrition and public awareness

The speeches drew attention to Mauritius's burden of non-communicable diseases, including diabetes and hypertension. Healthy diets, physical activity and other preventive practices were discussed as important components of well-being alongside conventional healthcare.

This focus reinforces the relevance of agriculture to public health. The foods we produce, their nutritional quality and the ways people understand and use them all shape dietary choices. It also creates opportunities for students and researchers to contribute to public education on food and nutrition.

The final address offered a more personal reflection on family health traditions and the importance of caring for one's health before illness develops. Alongside this appreciation of heritage, the event's broader message remained clear: healthcare decisions should be guided by reliable evidence and patient safety.

A resource for learning and collaboration

The Ayurveda Information Corner was presented as a starting point for sustained activity. Beyond access to literature, speakers envisaged lectures, workshops, student projects, research discussions and community outreach.

India-Mauritius cooperation was also highlighted through the AYUSH academic chair, training opportunities, scholarships and institutional partnerships. A planned AYUSH Centre of Excellence was described as a further opportunity to strengthen cooperation in traditional medicine.

From resource to activity

The Information Corner can support lectures, student projects, interdisciplinary research, professional discussions and community engagement.

For the Faculty of Agriculture, the celebration opens a conversation about how agricultural knowledge can contribute to healthier communities. By bringing together food, plants, environmental stewardship and rigorous research, that conversation can help translate the One Health theme into meaningful teaching, enquiry and public engagement.

Upgrading Biosecurity Why Mauritius New X Ray Irradiator Matters for Pest Control- Sterile Insect Technique

 

Agricultural biosecurity  |  Sustainable pest management

Mauritius has commissioned a machine-generated X-ray irradiator for its Sterile Insect Technique programme, strengthening the country's capacity to suppress agricultural pests without relying solely on broad-spectrum insecticides.

Machine-generated X-ray irradiator

Agricultural innovation in Mauritius has reached an important milestone with the commissioning of an X-ray irradiator at the Entomology Division in Réduit. The equipment was provided by the United States Department of Energy National Nuclear Security Administration's Office of Radiological Security, in collaboration with Lawrence Livermore National Laboratory.

Dr N. Patel of the Entomology Division with the Hon A. Boolell, Minister of AgroIndustry, Food Security and Blue Economy

The new system expands the country's capacity to use the Sterile Insect Technique, or SIT, against destructive agricultural pests such as fruit flies. It also replaces many of the security and logistical demands associated with irradiators that use radioactive isotopes.

Key takeaway

The X-ray irradiator allows Mauritius to sterilise agricultural pests without keeping a permanent radioactive source at the facility.

The technology supports pest suppression by interrupting reproduction rather than depending entirely on repeated pesticide applications.

How the Sterile Insect Technique works

SIT is a pest-management method that uses sterilised insects to reduce a target population over time. It is often described as a form of insect birth control.

1. 

   Preparation of fruit-fly pupae for X-ray irradiation under controlled laboratory conditions.

   
   Mass rearing Target insect pests are reared in controlled laboratory facilities.
2. Sterilisation Pupae or adult insects receive a carefully controlled dose of ionising radiation that makes them sterile while preserving the characteristics needed for mating.
3. Release Sterile males are released at planned intervals across the target agricultural area.
4. Population suppression Sterile males mate with wild females, but no offspring are produced. Repeated releases gradually reduce the pest population.

The shift from gamma sources to X-rays

SIT programmes have traditionally used gamma irradiators containing radioisotopes such as cobalt-60 or caesium-137. These systems are effective, but the radioactive source emits continuously and must be secured, regulated, transported and eventually replaced. An X-ray irradiator generates radiation electrically only while the machine is operating.

Improved radiological security

A gamma irradiator contains a radioactive source even when it is not being used. This requires strict physical security and specialised arrangements for transport, storage and disposal. An X-ray machine produces no machine-generated radiation once it is switched off, removing the need to manage a permanent radioactive source.

Electronic dose control

Operators can control the exposure electronically and adjust operating parameters for different insect batches. Reliable sterilisation still depends on dose mapping, calibration and quality assurance so that insects receive the intended dose throughout the treatment container.

Protection of insect fitness

Sterility alone is insufficient. Released males must still fly, survive and compete successfully with wild males. Accurate dosimetry and validated treatment protocols help avoid unnecessary exposure that could weaken the insects and reduce the effectiveness of field releases.

Simpler long-term operation

Radioisotope sources decay and require specialised replacement arrangements. X-ray equipment instead relies on electrical components that can be maintained or replaced through a conventional technical service programme. It removes the international transport and end-of-life management requirements associated with radioactive sources.

Why the change matters

The upgrade combines three benefits: lower radiological-security risk, electronically controlled operation and a more manageable long-term maintenance model.

What this means for Mauritian agriculture

For Mauritius, the value of the X-ray irradiator extends beyond the replacement of one piece of equipment. It strengthens the infrastructure needed for area-wide pest management and can support more targeted control of fruit flies that damage local fruit and vegetable production.

SIT works best as part of an integrated pest-management programme that also includes field monitoring, sanitation, surveillance and other appropriate control measures. Its contribution depends on reliable mass rearing, accurate irradiation, systematic releases and continued measurement of wild pest populations.

Field release and monitoring of sterile male fruit flies as part of an area-wide pest-management programme.

By adopting machine-generated irradiation, Mauritius can reduce the security burden associated with radioactive sources while maintaining an important biological tool for pest control. The investment also creates opportunities for applied research, technical training and collaboration between entomologists, crop specialists, engineers and biosecurity professionals.

Conditions for success

• Accurate dose calibration and routine quality assurance
• Healthy, competitive sterile males
• Well-planned releases across the target area
• Continued field monitoring and integration with other pest-control measures

Looking ahead

The new irradiator demonstrates how engineering can strengthen applied entomology and agricultural biosecurity. Its long-term impact will depend on careful operation, quality assurance and integration with field-level pest-management programmes. Used effectively, it can help protect local harvests while supporting a more precise and sustainable approach to agricultural pest control.

Agriculture, Public Health and Environmental Protection

Pesticides in Mauritius: Addressing the Risks of “Silent Killers”

Mauritius has established important legal controls on pesticides, but weaknesses in traceability, monitoring and enforcement continue to expose agriculture, public health and the environment to long-term risks.

Pesticides support agricultural production by controlling insects, plant diseases and weeds. When properly selected and responsibly applied, they can reduce crop losses and help farmers maintain reliable yields.

However, pesticides can also create risks that are difficult to see. Chemical residues may remain in food, soil and water without producing an immediate warning. Their effects may emerge only after repeated exposure over many years.

This is why the Office of the Director of Public Prosecutions has used the expression “silent killers” when discussing pesticides. The term draws attention to forms of harm that may develop gradually and remain unnoticed until they become serious or irreversible.

Key message

The central challenge is not whether pesticides should be regulated, but whether Mauritius can trace their movement, control their application and detect harmful residues before damage reaches consumers and ecosystems.

Why pesticides are called “silent killers”

Acute pesticide poisoning may cause visible effects such as skin irritation, burns, nausea or breathing difficulties. Chronic exposure is more difficult to recognise because it may involve repeated contact with small quantities quantities over a period of years.

Consumers cannot normally see, smell or taste pesticide residues. This invisible exposure makes prevention, testing and traceability especially important.

Chronic exposure

Small and repeated exposures may accumulate over many years before serious health effects become apparent.

Nervous system effects

Some pesticides interfere with biological mechanisms involved in nervous system signalling, creating concerns for non-target organisms and people.

Multiple residues

A meal may contain produce treated with several substances, creating potential exposure to a mixture or “cocktail” of chemical residues.

The health effects of pesticides depend on the chemical involved, the dose, the route of exposure and the duration of contact. Certain substances have been associated with neurological effects, endocrine disruption, reproductive harm or increased cancer risks.

The agricultural consequences are equally important. Excessive or inappropriate pesticide use can reduce beneficial soil organisms, including earthworms and microorganisms that contribute to soil fertility. Chemicals may also move through the soil, enter groundwater or be carried into rivers and coastal ecosystems.

A small-island vulnerability

Mauritius has limited land and freshwater resources. Contamination originating on agricultural land can therefore affect drinking-water reserves, aquatic life, coastal environments and communities located far beyond the original application site.

The Mauritian legal framework

Pesticide control in Mauritius is distributed across several laws and enforcement agencies. Each law addresses a different stage in the movement of chemicals from importation to agricultural use and, ultimately, to food sold to consumers.

Legislation	Main focus	Possible consequences
Dangerous Chemicals Control Act	Importation, classification, licensing, labelling, packaging, storage and distribution of dangerous chemicals	Fines, imprisonment, prohibition notices and seizure or destruction of prohibited chemicals
Use of Pesticides Act 2018	Agricultural application of pesticides and control of pesticide residues in produce intended for sale	Increasing fines for repeated offences and possible imprisonment
Food Act and Food Regulations	Safety of food offered to consumers and compliance with Maximum Residue Levels	Enforcement action against parties placing unsafe or non-compliant food on the market
Environment Act 2024, as amended in 2026	Serious environmental offences, including the criminal offence of ecocide under Section 135A	Proportionate fines, penal servitude, environmental restoration, compensation and recovery of clean-up costs

The Dangerous Chemicals Control Act requires licences for activities such as importing, manufacturing, selling, storing and distributing dangerous chemicals. Importing or exporting a pesticide or an extremely dangerous chemical also requires a permit.

Chemical labels and safety documentation play a central role in this system. Appropriate information should identify the hazards associated with a product, the precautions required during use and the conditions under which it should be stored.

The Use of Pesticides Act focuses specifically on agricultural application. The Food Act and its regulations provide an additional level of protection by controlling the pesticide residues permitted in food offered to consumers.

Effective protection depends on these laws operating as one connected system. Regulation at the border has limited value if authorities cannot subsequently determine where, when and how the imported chemical was used.

Are pesticide lists keeping pace with scientific evidence?

The schedules attached to chemical legislation identify substances subject to control and those whose importation, manufacture, use or possession is prohibited without written authorisation.

Concerns have been raised that these lists have not been updated frequently enough to reflect new scientific findings and international regulatory decisions. Some substances permitted or controlled in Mauritius may already be prohibited or no longer recommended in other jurisdictions.

International decisions should not automatically replace a national risk assessment. Mauritius has its own crops, climate, pests and production conditions. Nevertheless, when another jurisdiction prohibits a pesticide because of credible health or environmental evidence, that decision should trigger a timely scientific review in Mauritius.

A stronger review process should consider:

• New evidence on toxicity and long-term exposure
• Risks to groundwater, soil organisms and aquatic ecosystems
• Decisions taken by international regulatory authorities
• Whether safer and economically viable alternatives are available
• The agricultural necessity of retaining a particular substance

The critical traceability gap

The briefing highlighted the importation of approximately 3,100 tonnes of pesticides during 2025. However, the quantity imported does not reveal where these chemicals were applied, which crops received them or whether the volume used was proportionate to the area cultivated.

Mauritius does not yet have a complete system capable of tracing every pesticide from its point of importation to the individual field where it is applied.

A credible traceability system should record:

• The chemical and quantity imported
• The importer, distributor and final purchaser
• The crop and field on which the chemical was applied
• The dose, application date and person responsible
• The interval between application and harvesting
• The management of unused products and empty containers
• The results of any residue tests conducted on the produce

Digital records could allow authorities to compare the quantity purchased with the size of the cultivated area. A disproportionately high volume could automatically generate a warning and trigger an inspection.

Traceability would shift pesticide regulation from investigating damage after it occurs to identifying high-risk practices before contaminated produce reaches consumers.

Sampling and monitoring remain limited

Mauritius produces a substantial quantity of food crops each year. The briefing reported annual production of approximately 180 million kilograms, compared with around 800 pesticide-residue samples.

The figures illustrate the difficulty of drawing conclusions about the safety of an entire food system from a relatively small number of tests. Sampling cannot cover every farm or consignment, but it should be sufficiently broad and strategically targeted to identify areas of greatest risk.

High-risk crops

Prioritise produce with a history of non-compliance, intensive chemical treatment or frequent raw consumption.

Local and imported food

Apply comparable food-safety expectations to locally produced and imported fruits, vegetables, spices and other products.

Rapid results

Improve laboratory turnaround times so that perishable produce is not sold before a non-compliant result becomes available.

Monitoring should include imported produce as well as local crops. Fruits such as grapes and oranges, together with dried products and spices, may also carry residues and should form part of a risk-based testing programme.

Laboratory capacity is another challenge. Fresh produce is highly perishable, and test results may not always be available before the food has been distributed or consumed. Faster analytical methods and clear procedures for holding high-risk consignments could help address this weakness.

Illegal practices and enforcement concerns

Effective regulation must also address the possibility that restricted or prohibited substances continue to circulate. The detection of an unauthorised pesticide may result from illegal importation, incorrect documentation, old stocks or misuse of a product on a crop for which it was not approved.

Concerns have also been raised about farmers allegedly reserving small, minimally treated plots for household consumption while using heavier pesticide treatments on crops intended for sale. Although such claims require evidence and should not be generalised to the farming community, they demonstrate why independent monitoring is necessary.

Farmers who comply with the law may also be placed at an economic disadvantage when illegal products or unsafe practices reduce the production costs of non-compliant competitors. Strong enforcement therefore protects responsible producers as well as consumers.

Responsibility is shared across several institutions

• Ministry responsible for agriculture: safe pesticide use, farm inspections and monitoring of residues in agricultural materials
• Ministry responsible for health: health effects of chemical exposure and food-safety controls
• Ministry responsible for labour: occupational exposure, chemical storage and workplace safety
• Police: road transport of dangerous chemicals and emergency preparedness
• Fire and Rescue Service: chemical spills, fires, explosions and loss-of-containment incidents

Divided responsibilities make coordination essential. Inspection data, import records, residue results and information about environmental incidents should be shared through a common national system.

Ecocide and the new legal frontier

Mauritius introduced the criminal offence of ecocide through a 2026 amendment to the Environment Act 2024. Section 135A entered into force on 18 April 2026.

Under the amended legislation, ecocide involves an unlawful or wanton act committed with knowledge that there is a substantial likelihood of causing damage that is severe and either widespread or long-term.

Severe

Damage involving very serious adverse changes, disruption or harm to an element of the environment.

Widespread

Damage suffered by an entire ecosystem or species, or by a large number of people.

Long-term

Damage that is irreversible or cannot be repaired through natural recovery within a reasonable period.

Wanton

Conduct showing reckless disregard for damage that is clearly excessive in relation to the anticipated social and economic benefits.

A person convicted of ecocide may face penal servitude for up to ten years. Financial penalties are intended to reflect the gravity and duration of the damage, the offender’s circumstances and any financial benefit obtained from the offence.

Courts may also order environmental restoration, compensation and recovery of clean-up costs. Permits may be withdrawn, and a convicted person may be excluded from certain forms of public funding.

Ecocide does not criminalise ordinary farming

The offence sets a very high threshold. An isolated mistake or ordinary regulatory violation would not automatically amount to ecocide. In an extreme case, however, the deliberate or recklessly excessive release of a hazardous chemical causing severe and widespread ecosystem destruction or irreversible groundwater contamination could potentially attract scrutiny under Section 135A.

Moving from chemical dependence to agroecology

Enforcement alone cannot resolve the problem. Farmers also need practical alternatives that allow them to protect crops without jeopardising their income.

Agroecology and integrated pest management seek to reduce unnecessary chemical treatments by combining biological, ecological and agricultural methods.

• Regular field observation before deciding to spray
• Crop rotation and greater on-farm diversity
• Resistant crop varieties
• Biological control of pests
• Mechanical and cultural weed management
• Protection of beneficial insects and soil organisms
• Use of validated biopesticides where appropriate

A successful transition must be gradual and supported by research, training, extension services and financial incentives. Farmers should not be expected to abandon an effective treatment without access to a safe, affordable and reliable alternative.

Five priorities for Mauritius

1. Introduce digital traceability. Track pesticides from importation and sale to their application on individual farms and crops.
2. Increase risk-based sampling. Direct limited laboratory resources towards high-risk produce, previously non-compliant operators and vulnerable consumer groups.
3. Review pesticide lists regularly. Establish a transparent procedure for assessing new scientific evidence and international regulatory decisions.
4. Strengthen licensing and training. Ensure that pesticide applicators understand dosage, protective equipment, storage, pre-harvest intervals and container disposal.
5. Support agroecological alternatives. Connect regulation with research, farmer education, financial incentives and access to safer pest-management tools.

The role of universities

Universities can make an important contribution by connecting agricultural science, public health, environmental monitoring and legal analysis.

Research institutions can evaluate pesticide residues in food, soil and water; assess the effectiveness of safer alternatives; help design digital traceability systems; and provide independent evidence to policymakers.

Universities can also contribute to farmer education and public awareness. Communication should remain balanced: pesticides should neither be presented as harmless nor discussed in ways that create unnecessary fear. The objective is to promote informed decisions based on evidence, proportionality and prevention.

From invisible risk to preventive action

Mauritius already possesses much of the legal foundation required to regulate pesticides. The central weakness lies in the distance between the law as written and its consistent implementation across the agricultural and food supply chains.

More extensive monitoring, faster laboratory results, updated chemical lists and complete traceability would allow authorities to identify risks before they become public-health or environmental crises.

Protecting Mauritius from the silent effects of pesticides requires more than penalties. It requires a coordinated system that supports responsible farmers, protects consumers and prevents irreversible damage to the country’s soil, water and biodiversity.

Further reading

• Top FM Hard Talk August 2026
• Dangerous Chemicals Control Act
• Food Regulations 2024
• Environment Act 2024, as amended
• Report of Assises de l’Agriculture 2026

This article provides a general educational overview and does not constitute legal, medical or regulatory advice. Quantities and enforcement concerns attributed to the briefing should be interpreted in the context of the expert discussion from which they were drawn.