Sali Atanga Ndindeng

Selecting low‐toxicity pesticides for Integrated Pest Management (IPM) is vital to protecting non‐target natural enemies and maintaining ecosystem health. This study assessed the ecotoxicological risk and natural enemies' differential sensitivity to pesticide‐driven biodiversity threats in tropical wetland rice fields in Ndop, Cameroon. The ecotoxicological risks associated with current farming schemes of 626 farmers were assessed using the Pesticides RIsks in the Tropics to Man, Environment and Trade (PRIMET) model based on farmers' pesticide application schemes, toxicity endpoints of the most sensitive parasitic wasp ( Aphidius rhopalosiphi ) and predatory mite ( Typhlodromus pyri ) species, and pesticide physicochemical properties. Wilcoxon signed‐rank test was used to compare pesticide application concentrations and risk profiles, and pairwise ratio analysis was used for differential sensitivity analysis. Pearson correlation established relationships between variables. Approximately 76.46% of the 17 pesticides (paraquat dichloride, 2,4‐D amine, glyphosate, carbendazim, chlorothalonil, copper (I) oxide, maneb, mancozeb, metalaxyl, potassium phosphonate, acetamiprid, chlorpyrifos, cypermethrin, emamectin benzoate, fipronil, imidacloprid, lambda‐cyhalothrin) used by farmers were overused, with the PRIMET model predicting definite or possible risks to both species for all seven insecticides, and lambda‐cyhalothrin (ETR = 98 800) and cypermethrin (ETR = 122 000) posing the highest acute and chronic definite risks. The fungicides carbendazim, metalaxyl, maneb, and chlorothalonil posed a possible risk (ETR ≤ 100) to T. pyri , while mancozeb posed a definite risk (ETR = 189.7) to A. rhopalosiphi . In contrast, chlorpyrifos (ETR = 6213) and fipronil (ETR = 4463) posed the highest definite risks to A. rhopalosiphi. Overall risk levels did not differ significantly between the two species ( p < 0.9), with T. pyri sensitive to 42.9% of applied pesticides and showing 284‐fold higher differential sensitivity than A. rhopalosiphi , mostly to pyrethroids. Pearson correlation revealed a highly significant positive relationship between lethal rates and applied concentrations ( r = 0.723, p < 0.001). Farmers in wetlands should replace high‐risk pesticides, especially pyrethroids, and adopt IPM to reduce risks to non‐target beneficial arthropods.

Background and Objectives: Whole‐grain (brown) rice has superior nutritional quality but is prone to rancidity, primarily caused by endogenous lipases and oxidases. This study evaluated mild hydrothermal stabilization (MHS), comprising grain surface wetting, followed by short‐duration atmospheric‐pressure steaming, applied to two West African rice varieties. Rice was processed as mild hydrothermal stabilized paddy whole‐grain rice (MHS‐PWGR) and brown whole‐grain rice (MHS‐BWGR). Findings: With both MHS‐PWGR and MHS‐BWGR, lipase activity was not detected after 10 min steaming. Peroxidase activity was not detected after 5 min steaming. MHS improved grain lightness compared with conventional parboiling, giving a golden‐yellow color. MHS‐BWGR maintained acceptable brown head rice yield and essential mineral content (Fe, Zn, and Ca), (quantified by XRF). Cooking time and cooked‐grain hardness were reduced, particularly in MHS‐BWGR. Conclusions: Multi‐criteria decision analysis of the data identified 15 min steaming of MHS‐BWGR as the optimal treatment, combining undetectable enzymatic activity, good color, texture, and mineral quality. Significance and Novelty: MHS has considerable potential as a simple and effective process for improving the shelf life and quality of whole‐grain rice. It can be readily deployed with slight modifications to existing parboiling systems already in West African small‐ and medium‐scale rice mills and elsewhere.

This study explores the nutritional enhancement of germinated brown rice (GBR), commonly referred to as GABA rice, produced from Nigerian rice cultivars (FARO 44, FARO 52, and FARO 57). Paddy rice was germinated at 35°C for 0 (control), 12, 24, and 36 h, followed by parboiling and dehusking to obtain GBR. Nutritional analyses focused on mineral, vitamin, and phytic acid contents. Germination significantly increased macro‐minerals, including calcium, magnesium, phosphorus, and sodium, by up to 109.8%, 22.1%, 12.1%, and 149.0%, respectively after 36 h of germination. The levels of trace minerals such as zinc, iron, manganese, selenium, and cerium also increased, while phytic acid level decreased with longer germination durations. Vitamin content improved markedly, with increases of 387.5% for B1, 440.0% for B2, and 56.8% for vitamin E, after 36 h of germination. A 24 h germination period was optimal for mineral enrichment, while 36 h maximized the vitamin levels. These findings suggest that GBR, when integrated into conventional rice processing systems, could offer a cost‐effective dietary intervention for addressing micronutrient deficiencies and managing metabolic health disorders.

Soil nutrients depletion directly threatens sustainability of food systems by reducing agricultural productivity, degrading ecosystem services, thus increasing the need for external inputs. Frass, a nutrient-rich byproduct of insect farming, is increasingly recognized for its potential in sustainable agriculture. In the current study, we explored the effects of composted Black Soldier Fly (BSF) frass on the growth and yield of Solanum macrocarpon (African eggplant) and Lactuca sativa (Lettuce), as well as its effect on soil nutrient composition, compared to poultry manure and inorganic fertilizers (NPK and urea). Two field experiments were conducted separately for lettuce and the African eggplants, each involving six treatments and four replicates per crop species. For lettuce, treatments included: BSF frass at 20 t/ha (T1), poultry manure at 20 t/ha (T2), BSF frass at 20 t/ha + 100 kg/ha urea (T3), BSF frass at 10 t/ha + 100 kg/ha urea (T4), NPK (15:15:15) at 200 kg/ha + 100 kg/ha urea as positive control (T01), and unfertilized soil as negative control (T0). For African eggplant, treatments consisted of: BSF frass at 15 t/ha (T1), 10 t/ha (T2), and 5 t/ha (T3), poultry manure at 10 t/ha (T4), NPK (15:15:15) at 200 kg/ha + 100 kg/ha urea as positive control (T01), and unfertilized soil as negative control (T0). Plant growth parameters like plant height, number and size of leaves and yield were analyzed. The results showed that, BSF frass at 20t/ha and 10t/ha significantly performed better than the other fertilizers in promoting plant growth and increasing yield in lettuce (3.53 kg per 3m ² and 5.12 kg per 3m ² in season 1 and 2, respectively) and of the African eggplant (5.04 kg per m ² ). Yield improvements reached approximately 50% compared with inorganic fertilizer treatments. Post-harvest soil analysis showed significant differences among treatments for African eggplant in nitrogen (N), phosphorus (P), potassium (K), and electrical conductivity (EC), while for lettuce, only soil pH differed significantly. These findings suggest that BSF frass is a viable alternative to both inorganic and organic fertilizers, offering a sustainable solution for improving crop productivity and soil health.

Rice is a staple food in Côte d’Ivoire, but parboiling remains a weak link in the local rice value chain. Parboiled rice has superior nutritional and physical properties compared with white rice. In 2017, AfricaRice introduced the “Grain quality enhancer, Energy efficient, and durable Material” (GEM) parboiling system in Côte d’Ivoire to address these challenges. This study evaluated the rice value chain, parboilers’ perceptions of GEM technology, and its role in upgrading the rice value chain. Using two survey types (parboiler association level (focus group) and parboiler household level), 179 rice parboilers and 77 key players were randomly sampled and interviewed in Côte d’Ivoire. We used descriptive statistics and the parboiler budget for the profitability analysis. The results show that parboiling, primarily undertaken by women, is profitable in Côte d’Ivoire. Parboilers identified the key advantages of the GEM system, including improved rice quality, higher output rates, better nutritional value, and the ability to parboil larger volumes of rice. GEM technology enhanced rice quality, increased parboilers’ incomes, and reduced energy costs by 22.3%, saving an average of 73,090 FCFA per ton of parboiled paddy. The study recommends scaling up GEM technology through local fabricator training and broader dissemination in rice-growing regions to further strengthen the rice value chain in Côte d’Ivoire.

Mycotoxins such as aflatoxins (AFs), fumonisins (FBs), zearalenone (ZEN), and deoxynivalenol (DON) pose a risk to public health due to their carcinogenic potency (AFs and FBs) and anti-nutritional effects. The hazards associated with mycotoxins are accentuated where food management practices, control, and regulatory systems from farm to plate are sub-optimal. Information on the frequency of these mycotoxins in rice commercialized in markets in sub-Sahara Africa (SSA) is limited. The current study examined AF concentrations in 527 rice samples collected from 54 markets in five SSA countries. Grain quality characteristics, processing methods, and origin of samples were contrasted with toxin levels. In total, 72% of the samples had detectable AFs levels (range = 3.0 to 89.8 µg/kg). Forty-seven percent (47%) of the samples had AFs above 4 µg/kg, the European Union maximum level (ML), and were evaluated for cooccurrence with FBs, ZEN, and DON. Total AFs and ZEN cooccurred in 40% of the samples, and 30% of the positive ZEN samples had concentrations above the ML of 75 µg/kg. Total AFs did not co-occur with FBs and DON. Multivariate analysis revealed that length-to-width ratio (p < 0.0001), mixed variety for width (p = 0.04), and chalkiness (p = 0.009) significantly influenced aflatoxin concentrations. Slender grains had higher AFs concentrations than bold and medium grains (p < 0.0001). Possible strategies to mitigate mycotoxin contamination in rice include improving grain quality traits and practicing proper drying and hermetic storage before and after milling. These findings provide valuable insights for both domestic and international actors in establishing and strengthening regulations and management systems to mitigate rice mycotoxin contamination.