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Finding highly active molecular scaffold structures is always the key research content of new pesticide discovery. In the research and development of new pesticides, the discovery of new agricultural molecular scaffold structures and new targets still faces great challenges. In recent years, quinoline derivatives have developed rapidly in the discovery of new agriculturally active molecules, especially in the discovery of fungicides. The unique quinoline scaffold has many advantages in the discovery of new pesticides and can provide innovative and feasible solutions for the discovery of new pesticides. Therefore, we reviewed the use of quinoline derivatives and their analogues as molecular scaffolds in the discovery of new pesticides since 2000. We systematically summarized the agricultural biological activity of quinoline compounds and discussed the structure-activity relationship (SAR), physiological and biochemical properties, and mechanism of action of the active compounds, hoping to provide ideas and inspiration for the discovery of new pesticides.

Hypothesis : That conjugation of agrichemicals to pro-assembly hydrophobic moieties will enable enhanced compatibility and loading with host lyotropic liquid crystalline carrier matrix, and potentially self-assemble in their own right in aqueous environments. Experiments : A series of lipid-like agrochemical-conjugates were synthesized using specific amphiphilic entities conjugated onto the agrochemicals, picloram and 2,4-dichlorophenoxyacetic acid (2,4-D). The self-assembly behaviour and compatibility of the novel entities when incorporated into phytantriol and monoolein-based liquid crystalline systems were examined using small angle X-ray scattering, cryo-TEM and polarized optical microscopy. Findings : Compared to agrochemical-conjugates with simple alkyl ester groups, the esterification of the agrochemicals with amphiphilic groups such as phytantriol and monoolein led to greater structural compatibility and consequently a greater loading of the agrochemicals in the liquid crystalline systems without destabilizing phase structure. Picloram-monoolein and picloram-monoelaidin can self-assemble to form lamellar structures in water. However, certain agrochemical-conjugates such as picloram-monoelaidin and picloram-PEGn-oleate showed poor compatibility with liquid crystalline systems, resulting in phase separation. [ABSTRACT FROM AUTHOR]

This paper selects agricultural chemicals and economic data of six provinces and one city in East China from 2001-2014 and analyzes Tapio decoupling relationship between agricultural chemistry and agricultural economic growth in the context of agricultural non- point source pollution control. The paper decomposes the factors of the agriculture chemical input with LMDI decomposition and then clusters agricultural chemical efficiency of provinces in East China by K-means. The results show that with the growth of agricultural output, the agrochemical inputs amount of six provinces and one city in East China showed a trend of“first increase and then decrease”during 2001-2014. Under the background of agricultural non-point source pollution control, the relationship between agricultural chemistry and agricultural economic growth presents absolute decoupling relationship. Agricultural economic growth and environmental resource protection can be developed coordinately, and the agricultural non-point source pollution control policy can be sustainably implemented based on the adjustment of agricultural chemical participation. The increase of agricultural chemical inputs is mainly caused by the land effect. The efficiency effect can slow down the growth of agricultural chemical inputs. The increase of agricultural output value of per unit, which depends on the agricultural chemicals production, is the driving force of the rapid increase of agricultural chemical inputs, and the progress of science and technology of agricultural chemicals production can reduce the amount of agricultural chemical inputs and ensure agricultural output value per unit area. There is great spatial difference in the dependence of the agricultural economy growth on agricultural chemicals. The dependence of agricultural economy growth on agricultural chemical is higher in Anhui Province. In short, agricultural economic can grow sustainably if agricultural nonpoint source pollution is controlled. To control agricultural chemicals, we need to improve the utilization rate of agricultural chemistry, use a variety of agricultural efficiency means and take the regional differences in consideration. [ABSTRACT FROM AUTHOR]

Agricultural chemicals may have an adverse impact on environment and food safety. The demand prices of such chemicals reveal farmers' willingness to pay and their preferences. This article examines the determinants of the agricultural chemicals price in the export-oriented vegetable production area, Anqiu, Shandong Province, applying the Hedonic Price Model based on the spatial econometric technique to analyze the price. We find that the agricultural chemicals with a different shape and function have different equilibrium prices, and the chemical attributes of permeability, rainfastness, being a substitute of the highly poisonous chemical, having a zero residue, and the internal absorption can all influence the equilibrium prices remarkably. We also find that the prices of biological and non-pollution agricultural chemicals might not be higher than the ordinary agricultural chemicals with the same characteristics. These findings do not show a good sign to the new agricultural chemicals promotion and environmental protection, and should be brought to the government's attention.

Traditional sprayers adopt large-area uniform pesticide application, resulting in a low effective utilisation of pesticide and a harmful effect to the natural environment. Variable-rate spray is the key point to precision chemical application. However, it is inevitable that the spray pressure sharply fluctuates during variable-rate spray, which will definitely influence the spray characteristics, such as spray droplet sizes, spray angles, spray droplet velocities, etc., and reduce the efficiency of pesticide applications. Therefore, the research on how to keep the spray pressure constant during the process of variable- rate spray has practical significance to precision pesticide applications. In order to achieve the stability of spray pressure for variable- rate spray, a sprayer with constant-pressure control was set up using a closed-loop proportion integration differentiation (PID) controller of constant-pressure water-supply, which employed the techniques of single-phase alternating current (AC) chopper variablevoltage control and PID feedback regulation. Using hollow-cone nozzles, the spray volume was changed by adjusting spray pressure, frequency, and duty cycle of electromagnetic valve switching. The spray features concerning the spray angle and the spray volume distribution were studied in laboratory. The conclusions are as follows: i) for a given input spray pressure, the closed-loop controller with AC chopper and PID feedback regulation can effectively control the pressure fluctuations during the variable-rate spray through varying the frequency and the duty cycle; ii) the spray angle was slightly affected by the flow-rate change through adjusting the frequency and the duty cycle of electromagnetic valves or changing the number of open nozzles. The spray angle changes were controlled within the range of the maximum deviation 0.87° from mean value and the minimum deviation 0.03° from mean value; iii) when the spray pressure was set as 0.3 Mpa, the peak radial position of the spray volume distribution basically unchanged and the spray volume and the peak values of the spray distribution gradually increased with the increasing duty cycle. When the setting pressure was increased, the spray volume increased and the peak radial position of the spray distribution gradually expanded toward outside, however the peak value of the spray distribution decreased a little. [ABSTRACT FROM AUTHOR]

Powdery mildew is one of the most devastating diseases in cucurbits. Crop yield can decline as the disease severity increases. In this study, we evaluated the effect of silver nanoparticles against powdery mildew under different cultivation conditions in vitro and in vivo. Silver nanoparticles (WA-CV-WA13B) at various concentrations were applied before and after disease outbreak in plants to determine antifungal activities. In the field tests, the application of 100 ppm silver nanoparticles showed the highest inhibition rate for both before and after the outbreak of disease on cucumbers and pumpkins. Also, the application of 100 ppm silver nanoparticles showed maximum inhibition for the growth of fungal hyphae and conidial germination in in vivo tests. Scanning electron microscope results indicated that the silver nanoparticles caused detrimental effects on both mycelial growth and conidial germination. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the possibility of aromatic β-selenolactams being used in agricultural chemicals. A series of β-selenolactams with aromatic substituents at the 1-, 2- and 3-positions were synthesized and their bioactivities were evaluated. Acarianicidal and insecticidal activity against common destructive insects, antibacterial activity against seven common plant pathogens, and plant growth activity of typical food crops were investigated. We found that introduction of 4-chloro and 4-methyl groups on 2- or 3-phenyl groups of the β-sele-nolactam ring brought about acarianicidal activity against adults and eggs of Plutella xylostella. However, except for moderate to weak effect on fatality of Culex pipiens molestus Forskal, insecticidal activity against two other kinds of insects, antibacterial activity against plant pathogens, and activity on plant growth regulation were not detected among the β-sele-nolactam derivatives. [ABSTRACT FROM AUTHOR]

Dermatitis in agricultural workers, albeit a common entity, infrequently receives scrutiny as to mechanism and prevention. We briefly describe potential mechanisms, examples for each, and offer an algorithm for etiologic diagnoses. [ABSTRACT FROM AUTHOR]

Abstract: Dithiocarbamates form a large group of chemicals that have numerous uses in agriculture and medicine. It has been reported that dithiocarbamates, including thiuram (tetramethylthiuram disulfide), cause wavy distortions of the notochord in zebrafish and other fish embryos. In the present study, we investigated the mechanism underlying the toxicity of thiuram in zebrafish embryos. When embryos were exposed to thiuram (2–1000 nM: 0.48–240 μg/L) from 3 h post fertilization (hpf) (30% epiboly) until 24 hpf (Prim-5), all embryos develop wavy notochords, disorganized somites, and have shortened yolk sac extensions. The thiuram response was specific and did not cause growth retardation or mortality at 24 hpf. The thiuram-dependent responses showed the same concentration dependence with a waterborne EC50 values of approximately 7 nM. Morphometric measurements revealed that thiuram does not affect the rate of notochord lengthening. However, the rate of overall body lengthening was significantly reduced in thiuram-exposed animals. Other dithiocarbamates, such as ziram, caused similar malformations to thiuram. While expression of genes involved in somitogenesis was not affected, the levels of notochord-specific transcripts were altered after the onset of malformations. Distortion of the notochord started precisely at 18 hpf, which is concomitant with onset of spontaneous rhythmic trunk contractions. Abolishment of spontaneous contractions using tricaine, α-bungarotoxin, and a paralytic mutant sofa potato, resulted in normal notochord morphology in the presence of thiuram. These results indicate that muscle activity is necessary to reveal the underlying functional deficit and suggest that the developmental target of dithiocarbamates impairs trunk plasticity through an unknown mechanism. [Copyright &y& Elsevier]

Bacterial wilt caused by Ralstonia solanacearum is a distributed and worldwide soilborne disease. The application of biocontrol microbes or agricultural chemicals has been widely used to manage tomato bacterial wilt. However, whether and how agricultural chemicals affect the antagonistic ability of biocontrol microbes is still unknown. Here, we combined potassium phosphite (K-Phite), an environmentally friendly agricultural chemical, and the biocontrol agent Bacillus amyloliquefaciens QPF8 (strain F8) to manage tomato bacterial wilt disease. First, K-Phite at a concentration of 0.05% (wt/vol) could significantly inhibit the growth of R. solanacearum . Second, 0.05% K-Phite enhanced the antagonistic capability of B. amyloliquefaciens F8. Third, the greenhouse soil experiments showed that the control efficiency for tomato bacterial wilt in the combined treatment was significantly higher than that of the application of B. amyloliquefaciens F8 or K-Phite alone. Overall, our results highlighted a novel strategy for the control of tomato bacterial wilt disease via application and revealed a new integrated pattern depending on the enhancement of the antagonistic capability of biocontrol microbes by K-Phite.