Water treatment (WT) is currently among the major areas of research due to the depletion of water resources and fearmongering regarding environmental pollution, which has compelled the upgrading of conventional WT technology towards recycling and reuse. This review aims to provide the current state of natural coagulants and their application in the purification of surface water as sufficient clean water is required for household needs, health security, and environmental safety. A thorough and systematic review of the existing literature was performed, and the information related to water treatment using natural coagulants was compiled from 237 articles under various sections using a computerized bibliographic search via PubMed, Scopus, Web of Science, Google Scholar, CAB Abstracts, and several websites. The work provides explicit information related to natural coagulants and their merits and limitations, outlines methods to increase their coagulation performance, and highlights their coagulation mechanism, efficacy, valorization potential, and sustainability. From the information obtained, it can be concluded that although chemical coagulants are efficient in WT, they are usually expensive, toxic, associated with health issues, and thus non-sustainable. A sustainable alternative is the use of natural coagulants, which are readily available, economical, easy to use, biodegradable, non-toxic, eco-friendly, effective, and generate lower sludge volumes. They work via an adsorption process that involves polymeric bridging or neutralization of the charge. The WT efficiency of natural coagulants ranges from 50–500 nephelometric turbidity units (NTUs), which is similar to chemicals. Thus, they can be deployed in WT regimes and can contribute to the health security of rural populations in developing countries. It is unfortunate that, despite the known benefits of natural coagulants, their acceptance, commercialization, and widespread industrial application across the globe are still low. Therefore, there is a need for more exhaustive investigations regarding the mode of action, adoption, and commercialization of natural coagulants as a sustainable alternative to chemicals for a circular economy.

The whitefly (Bemisia tabaci Gennadius) is a notorious devastating sap-sucking insect pest that causes substantial crop damage and yield losses due to direct feeding by both nymphs and adults and also through transmission of viruses and diseases. Although the foliar application of synthetic pesticides is crucial for efficient control of B. tabaci, it has adverse effects such as environmental pollution, resistance and resurgence of the pest, toxicity to pollinators, and crop yield penalty. Thus, a suitable, safe, and robust strategy for the control of whiteflies in the agricultural field is needed. The reports on whitefly-resistant transgenic plants are scanty, non-reproducible, and/or need secondary trials and clearance from the Genetic Engineering Appraisal Committee (GEAC), the Ministry of Environment and Forests (MoEF), and the Environmental Protection Agency (EPA). The present review encompasses explicit information compiled from 364 articles on the traditional, mechanical, biological, biotechnological, and chemical strategies for whitefly management (WFM), IPM strategy, and future prospects of WFM for food and agriculture security.

The eggplant (Solanum melongena L.) is among the vital fruit vegetables cultivated globally for its health and nutritional benefits. However, its production has been hindered by whiteflies (Bemisia tabaci G.) infestation worldwide. This study aims to assess the effect of some bio-pesticides in the control of whiteflies on eggplants under field conditions. The trial consists of seventeen (17) treatments replicated three times for 45 days. From the results obtained, neem leaf extract (60 mL/L) proved more effective against whiteflies, with 1.2 and 1.3 adults/leaf, while buttermilk and cow dung (50 mL/L) were less effective (10.1 and 10.8 adults/leaf) when compared to untreated plots (26.9 and 33.4 adults/leaf), two weeks after the third spray during the first and second trials. The highest reduction (%) in whitefly population was found using neem leaf extract (95.7 and 96.1%) and cow urine (85.8 and 96.1%), with cow dung and buttermilk exhibiting the least overall averages (65.9 and 62.3%), two weeks after the third spray during the respective trials. Neem extract and cow urine were more effective among the treatments examined and, thus, recommended to be incorporated into control strategies of whiteflies for the improved production of eggplants in the area.

Whiteflies (Bemisia tabaci Genn.) are aggressive hemipteran species that depend primarily on leaf tissue for their nourishment, causing substantial damages and yield losses in their hosts. This study was carried out to assess the effect of whitefly infestation on the growth parameters of one of the commercial eggplant cultivars (round green Solanum melongena L) under filed conditions. The trial consists of four treatments (T1= 15, T2= 30, T3= 45 and control (T4) = 0 whiteflies/plot) replicated four times. The result revealed that all the parameters assessed are negatively affected by whitefly infestation with plants in treatment (T3) being most affected while those in T1 are least affected. The dry weight recorded least value (1.1 g/leaf) having the highest percentage reduction (69.11%) followed by leaf area with 152.5cm2 (48.83% reduction) while the number of leaves was least affected recording 50.3 leaves/plant (18.09% reduction) at 90 days after infestation in 2022 experiment. In 2023 experiment, similar results were recorded with plants in T3 being most affected. Dry weight of the leaves had the lowest value (1.3g/leaf) representing the highest reduction (68.30%) followed by the leaf area with 167.3cm2 (44.8% reduction) with the number of leaves also being least affected, recording 52.1 leaves/plant representing 9.40% reduction with plants in treatment T1, at 90 days after infestation. The highest reduction in yield was also recorded with plants in T3 (92.10, 90.10%) while the least was observed in T1 (86.8 and 85.70%) for the respective trials (2022 and 2023). The result shows the level of susceptibility of the variety examined to whitefly infestation, demonstrating the urgent needs for the development of eco-friendly and sustainable whitefly management regimes for improved eggplant production in the area.