Pyrene-Based Fluorescent Porous Organic Polymers for Recognition and Detection of Pesticides

Eating vegetables with pesticide residues over a long period of time causes serious adverse effects on the human body, such as acute poisoning, chronic poisoning, and endocrine system interference. To achieve the goal of a healthy society, it is an urgent issue to find a simple and effective method to detect organic pesticides. In this work, two fluorescent porous organic polymers, LNU-45 and LNU-47 (abbreviation for Liaoning University), were prepared using π-conjugated dibromopyrene monomer and boronic acid compounds as building units through a Suzuki coupling reaction. Due to the large π-electron delocalization effect, the resulting polymers revealed enhanced fluorescence performance. Significantly, in sharp contrast with the planar π-conjugated polymer framework (LNU-47), the distorted conjugated structure (LNU-45) shows a higher specific surface area and provides a broad interface for analyte interaction, which is helpful to achieve rapid response and detection sensitivity. LNU-45 exhibits strong fluorescence emission at 469 nm after excitation at 365 nm in THF solution, providing strong evidence for its suitability as a luminescent chemosensor for organic pesticides. The fluorescence quenching coefficients of LNU-45 for trifluralin and dicloran were 5710 and 12,000 (LNU-47 sample by ca. 1.98 and 3.38 times), respectively. Therefore, LNU-45 serves as an effective “real-time” sensor for the detection of trifluralin and dicloran with high sensitivity and selectivity.

Photodegradation of Flucetosulfuron, a Sulfonylurea-Based Herbicide in the Aqueous Media Is Influenced by Ultraviolet Irradiation

Photodegradation (photolysis) causes the breakdown of organic pesticides molecules by direct or indirect solar radiation energy. Flucetosulfuron herbicide often encounters water bodies. For this reason, it is important to know the behavior of the compound under these stressed conditions. In this context, photodegradation of flucetosulfuron, a sulfonylurea-based herbicide, has been assessed in aqueous media in the presence of photocatalyst TiO2 and photosensitizers (i.e., H2O2, humic acid, and KNO3) under the influence of ultraviolet (UV) irradiation. The influence of different water systems was also assessed during the photodegradation study. The photodegradation followed the first-order reaction kinetics in each case. The metabolites after photolysis were isolated in pure form by column chromatographic method and characterized using the different spectral data (i.e., XRD, IR, NMR, UV-VIS, and mass spectrometry). The structures of these metabolites were identified based on the spectral data and the plausible photodegradation pathways of flucetosulfuron were suggested. Based on the findings, photocatalyst TiO2 with the presence of ultraviolet irradiation was found effective for the photodegradation of toxic flucetosulfuron residues under aqueous conditions.

Distribution and Abundance of Macrobrachium Populations in Palawan

Nothing is known about the population dynamics of Macrobrachium spp. or freshwater decapods in Palawan that hence received little attention to conservation studies that are imperative to establish sustainable management proposals. Thus, this paper provides information on the natural distribution and abundance of Macrobrachium spp. in Palawan to address threats to their survival. Preliminary findings through key informant’s interviews suggest the distribution and abundance of these species in Palawan’s river system. Generally, Macrobrachium spp. are present in all river systems in the province. However, the respondents observed that the population started to decline during the late 1990s attributed to the rampant use of organic pesticides/insecticides for agricultural purposes and intensive quarrying activities stretched along with the river systems in some of the municipalities in Palawan. Results also annotated that the local populations use these animals as food without official regulations, which may be additional pressure on freshwater prawns. The abundance of the Macrobrachium spp. is affected by human interventions and the destruction of their natural habitat and populations. Management measures should be considered from the economic conditions of freshwater prawns for effective management strategy and conservation efforts for future generations.

Analysis of factors affecting income of organic curly red chili (Capsicum annum L.) in Gedangan Village, Cepogo District, Boyolali Regency

This study aimed to analyze factors affecting income of organic curly red chili farming in Cepogo District, Boyolali Regency. The samples in this study were selected using random sampling method. Results shows the average cost per hectare in total cost, income earn by farmer after sales, and income received per farm are Rp. 5,637,058; Rp. 110,050,711; and Rp. 105,914,352, respectively. The factors affecting chili production are land area, seeds, liquid organic fertilizer, labor costs, and pesticides. To get better chili production, a good preparation to handling weather and climate changes is needed. In here, those two factors seem to have great impact on the spread of pest and disease as evidenced by high cost of organic pesticides and liquid organic fertilizers.

EFEKTIVITAS PESTISIDA ORGANIK EKSTRAK KULIT JERUK NIPIS TERHADAP KEMATIAN JANGKRIK

Pestisida organik adalah pestisida yang bahan dasarnya berasal dari tumbuhan yang bersifat mudah terurai di alam. Salah satu tumbuhan yang dapat dijadikan bahan baku pembuatan pestisida organik adalah kulit jeruk nipis. Kulit jeruk dapat berpotensi menjadi repellent karena mengandung minyak atsiri dengan komponen limonene, mirsen, linalool, oktanal, decanal, sitronelol, neral, geraniol, valensen dan sinensial. Linalool, sitronelol dan geraniol termasuk senyawa yang bersifat repellent terhadap serangga (arthropoda). Pengunaan bahan alami dari ekstrak kulit jeruk diharapkan lebih aman jika dibandingkan dengan bahan kimia Dichloro Diphenyl Trichloroethane (DDT). Proses pembuatan pestisida organik dilakukan dengan ekstraksi maserasi menggunakan ethanol sebagai pelarut. Dalam penelitian ini bertujuan untuk mengetahui pengaruh variabel terhadap hasil pengujian pestisida organic terhadap jangkrik. Hasil penelitian menunjukkan pada konsentrasi pestisida organic 5% didapatkan prosentase kematian jangkrik 72%, pada konsentrasi 15% didapatkan prosen kematian jangkrik 80%, dan pada konsentrasi 25% didapatkan prosen kematian jangkrik 88%. Hasil penelitian menunjukkan bahwa adanya pengaruh terhadap perbedaan konsentrasi pestisida organic terhadap kematian jangkrik. Kata kunci: jeruk nipis, maserasi, pestisida organik AbstractOrganic pesticides are pesticides whose basic ingredients come from plants that are easily biodegradable in nature. One of the plants that can be used as raw material for making organic pesticides is lime peel. Orange peel can potentially be a repellent because it contains essential oils with components of limonene, mirsen, linalool, octanal, decanal, citronellol, neral, geraniol, valensen and sinensial. Linalool, citronellol and geraniol are compounds that are repellent to insects (arthropoda). The use of natural ingredients from orange peel extract is expected to be safer when compared to the chemical Dichloro Diphenyl Trichloroethane (DDT). The process of making organic pesticides is done by maceration extraction using ethanol as a solvent. This study aims to determine the effect of variables on the results of testing organic pesticides on crickets. The results showed that at 5% organic pesticide concentration, 72% of crickets died, at 15%, 80% of crickets died, and at 25%, 88% of crickets died. The results showed that there was an effect on differences in the concentration of organic pesticides on the mortality of crickets.. Keywords: lime, maceration, organic pesticide

Ecological and Human Diet Value of Locusts in a Changing World

Since ancient times, locusts have been serious pests wreaking havoc on settled agriculture throughout much of the world. Numerous locust practices have been developed to control infestations. This has led to most commentaries portraying locust infestations only in a negative light while focusing on finding best management practices for suppressing locust populations and lessening crop damage caused by swarms. Yet, locusts are also of great ecological significance in being not only an extraordinary natural phenomenon but also major components of ecosystem nutrient cycling, arising long before settled agriculture. Furthermore, for humans, locusts are a nutritious food source, historically and currently being consumed directly. Locust control today should more regularly include their harvesting. This is now more feasible, as environmentally friendly biopesticides can be used to replace harmful organic pesticides. We focus here on the ecological significance of locusts by using calculations based on a 1 km2 area of swarming and breeding Desert locusts, Schistocerca gregaria, and show that the huge biomass of locust individuals contributes greatly to ecosystem processes while also having great potential use in human nutrition, especially where there is an urgent need for improved dietary intake and nutrition.

A REVIEW OF BIOPESTICIDE PRODUCTS AS ECOLOGICAL ALTERNATIVE AGAINST FALL ARMYWORM (SPODOPTERA FRUGIPERDA) IN AFRICA

Spodoptera frugiperda, Fall Armyworm (FAW), poses an existential threat to farmers in Africa given their destructive effect on crops. This is essentially the case in south-eastern Nigeria where major crops such as cassava and maize are highly vulnerable to the adverse effects of the pest. This paper reviewed published work on the availability of biopesticides that can control FAW without compromising environmental sustainability. Altogether, 50 active ingredients have been identified as potential biopesticides to control fall armyworm globally, out of which 29 were described in Africa. Although there are reports of remarkable successes in the application of these organic pesticides, there is a need to identify more biopesticides and also establishing the most effective modes of application for managing the pest. This review examines possible biopesticides that may be used in controlling FAW in Africa and also provides insight for further research.