Dr Vedendranand Sharma Chummun
SCIENTIFIC OFFICER
National Environmental Laboratory
Ministry of Environment, Solid Waste Management and Climate Change
Republic of Mauritius
PhD Environmental Sciences –Open University of Mauritius
A study based on assessing the production of Daucus carota under different conditions was carried out in Mauritius. The first part of the study was a survey where 300 farmers were interviewed to assess the environmental, socio-economic and agricultural impact of using pesticides and fertilizers. The results showed that farmers were strongly influenced by fellow farmers to use pesticides in crop production and 44 % farmers exceeded the dosage of pesticides.
The second part of the study assessed three different soil amendments, namely: compost, manure and chemical fertilizer together with two most commonly used pyrethroid pesticides; Cypermethrin and Deltamethrin which were applied at two different rates on the Daucus carota that was grown under seven different treatments in two different regions. The effect of the soil amendments on the yield of Daucus carota was assessed in terms of heavy metals; cadmium, lead, and zinc. Subsequently, the residue of the two pesticides were analyzed in harvested Daucus carota using the GS-MS QuEChERS method.
Heavy metals were within the range except for cadmium at Region 1 for T5, T6 and T7 and Region 2 for T6 and T7. For pesticides residue, the results showed that for both regions, T3 and T6 obtained higher yield as compared to T4 and T7. For pesticide level in carrot crops, values obtained for Cypermethrin and Deltamethrin for treatment T4 and T7 exceeded the Maximum Residue Limits (MRL) in most cases. Treatment T6 (fertilizer) produced the best yield in both locations.
For the last part of the study, a life cycle assessment was conducted for the recommended treatment (T3) and the baseline treatment (T6) where the environmental impacts of the two treatments were examined to produce 1 ton of carrots. The results demonstrated that both treatments can contribute towards harm to the environment and human health. Finally, the findings of this study demonstrated that if pesticides are applied in the right
dosage and the frequency of applications is respected, these do not represent a problem for human health. Consequently, the optimum practice for crop productivity remains the use of environmentally friendly inputs. The findings of the study also recommended the use of artificial intelligence in the detection of pesticide residue at an early stage of crop production.