Les effets des mélanges de pesticides

Typology of Tomato Cropping Systems and Determinants of Preharvest Losses in Western Cameroon

Preharvest losses, which are often neglected, limit the availability of fresh tomato fruit to varying degrees in tomato-based cropping systems in Cameroon. Increasing tomato yields requires identifying, understanding, and controlling the factors responsible for preharvest losses in the identified cropping systems. Field surveys were conducted in three production areas of western Cameroon (Foumbot, Bansoa, and Dschang) to characterize cropping systems and growers, quantify production losses, and identify causal factors associated with losses and proffer solutions. One hundred and ninety-six growers were interviewed in 13 villages, using purposive sampling to select zones and simple random sampling to select growers. Factor analysis for mixed data (FAMD) and canonical discriminant analysis, combined with multinomial logistic regression, were used to analyze the collected data. The FAMD results indicated that 72% of the farm variability was expressed through technical route, preharvest losses, and technical mastery. The tomato-based cropping systems were classified into three types: (1) a pure cultivation system that consumes excessive synthetic fertilizers and results in significant losses; (2) a pure cultivation system that consumes high amounts of synthetic fertilizers and moderate amounts of organic fertilizers with moderate losses; and (3) a cultivation system that involves moderate synthetic fertilizer consumption, extremely low organic amendment, and low losses. Preharvest losses can be significantly affected by the unregulated use of synthetic fertilizers. The study's implications are many, affecting agricultural practices, policy, economic stability, and food security in Cameroon. A more sustainable and productive tomato industry can be achieved by addressing preharvest losses through informed strategies. To address this issue, it is crucial to establish fertilization protocols that consider the soil's fertility status and the tomato's essential macro- and micronutrient requirements.

Self-reported health effects of pesticides among cotton farmers from the Central-West region in Burkina Faso

Pesticides are chemicals used to control pests with sometime harmful effects on human health. This paper presents results of self-reported health effects experienced by cotton farmers in the Central-West region of Burkina Faso. It was a cross-sectional survey conducted from October to December 2021 among 585 consenting conventional and organic cotton farmers. Data collected included pesticides used, they use conditions, farming practices, experienced health effects. Binary logistic regression was used to find relationships between self-reported health effects and the type of cotton produced. Results showed that all conventional cotton farmers (100%) reported using synthetic pesticides compared to organic ones who using only natural insecticides. Both conventional and organic farmers reported health effects that occurred at least once since they started using pesticides, involving skin effects (85.27% conventional, 65.52% organic), nervous (88.95% conventional, 48,71% organic), respiratory (88.10% conventional, 67.67% organic) systems. 99.72% of conventional farmers vs 46.98% of organic ones reported skin irritation following pesticide use. 69.97% of conventional vs 35.34% of organic cotton farmers reported acute signs such as severe headaches. In univariate and multivariate logistic regressions, severe headaches, dizziness, skin, and ocular effects were significantly associated with conventional farmers compared to organic ones (p < 0.05). There was a significant relationship between vomiting (p = 0.014), diarrhea (p = 0.003) and experience in synthetic pesticide use among conventional farmers. Among organic farmers, there was no significant relationship between health effects reported and experience in organic insecticides use. there was a significant relationship between severe headaches (p = 0.01), rhinitis (p = 0.006), cough (p = 0.0001), skin and ocular irritations (p = 0.007) and the frequency of synthetic insecticides use per year by conventional farmers. Study showed that conventional and organic cotton producers experience the same types of health effects. However, these health effects were significantly associated with conventional farmers compared to organic ones.

Biocide emissions from building materials during wet weather: identification of substances, mechanism of release and transfer to the aquatic environment

Biocides are added to or applied on building materials to prevent microorganisms from growing on their surface or to treat them. They are leached into building runoff and contribute to diffuse contamination of receiving waters. This review aimed at summarizing the current state of knowledge concerning the impact of biocides from buildings on the aquatic environment. The objectives were (i) to assess the key parameters influencing the leaching of biocides and to quantify their emission from buildings, (ii) to determine the different pathways from urban sources into receiving waters and (iii) to assess the associated environmental risk. Based on consumption data and leaching studies, a list of substances to monitor in receiving water was established. Literature review of their concentrations in the urban water cycle showed evidences of contamination and risk for aquatic life, which should put them into consideration for inclusion to European or international monitoring programs. However, some biocide concentration data in urban and receiving waters is still missing to fully assess their environmental risk, especially for isothiazolinones, iodopropynyl carbamate, zinc pyrithione and quaternary ammonium compounds, and little is known about their transformation products. Although some models supported by actual data were developed to extrapolate emissions on larger scales (watershed or city scales), they are not sufficient to prioritize the pathways of biocides from urban sources into receiving waters during both dry and wet weathers. Our review highlights the need to reduce emissions and limit their transfer into rivers and reports several solutions to address these issues.