The systemic acaricidal activity of N-mono-and N, N-disubstituted chloromethanesulfonamides against citrus red mites (Panonychus citri MCGREGOR) was determined by applying them to soil. The structure-activity relationships were analyzed using the ORMUCS method. In both series, the activity was highly correlated to the hydrophobicity (π), the steric bulkiness (E^C_S) and the electron donating property (σ_I) of the N-substituted groups.

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A number of 1-[2-(2-substituted hydroxy-5-substituted phenyl) allyl] imidazole derivatives and their related compounds were newly synthesized. The allylimidazoles showed a potent activity in vitro against Botrytis cinerea, a phytopathogenic fungus. The relationship between structure and activity was examined quantitatively using physicochemical and structural parameters and regression analysis. Hydrophobicity of the molecule was the most important factor for the activity. The activity increased as the hydrophobicity increased and bulkiness of a substituent at the 5-position on the benzene ring decreased. Unsubstitution at the 5-position on the benzene ring did not favor the activity, however. Conversion of a double bond of the allyl moiety to a single bond deteriorated the activity. The present series of allylimidazoles was higher in activity than the previous series of the corresponding 1-[1-(2-substituted hydroxy-5-substituted phenyl) vinyl] imidazoles, which has been reported.

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One hundred and twelve N-aryl-2-methyl-2-arylpropanamides and N-aryl-2-methyl-2-arylbutanamides were synthesized and their herbicidal activities were measured. Most of the compounds exhibited strong herbicidal activity against Echinochloa oryzicola VASING., Scirpus juncoides ROXB. subsp. juncoides ROXB. and Cyperus serotinus ROTTB. in pot tests. Introduction of substituents into the two benzene rings varied the activity to different extents. Both a meta alkyl substituent in the amine moiety and an ortho substituent in the acid moiety contributed to high activity, whereas introduction of strong electron-withdrawing substituents at the para position in the amine moiety or bulky substituents at the para position in the acid moiety was unfavorable to the activity. Among the compounds, N-(3-propylphenyl)-2-methyl-2-(2-methoxyphenyl) butanamide showed the strongest activity against the test plants, completely killing Echinochloa oryzicola VASING. at a dose of 0.625g a. i./a in pot tests.

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Photolysis of DTP [4-(2, 4-dichlorobenzoyl)-1, 3-dimethyl-5-hydroxypyrazole], a hydrolysate and herbicidal entity of pyrazolate, was studied in water and on soil surface, using ¹⁴C-preparations labeled either at the 3rd position of the pyrazole ring or uniformly at the benzene ring. On exposure to sunlight, DTP in paddy water decomposed approximately twelve times faster, with the half-life of about 6 days, than in distilled water. Photolysis profile of DTP in paddy water was quite similar in both quality and quantity between two types of soil. On thin-layer plates of two types of soil, DTP gradually decomposed under sunlight. DTP underwent oxidation at the 1- and 3-methyl groups, cleavage of the benzoyl linkage, fission of the pyrazole and benzene rings, and was ultimately photomineralized. No volatilization of DTP from either water or soil was observed.

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A number of new aminosulfenyl derivatives of Carbofuran, linking different N-substituted amino acid esters and its analogs to the carbamyl nitrogen atom of Carbofuran (2, 3-dihydro-2, 2-dimethyl-7-benzofuranyl N-methylcarbamate) through a sulfur bridge, were synthesized, and their insecticidal activity and toxicity to mice were examined. Derivatization generally resulted in substantial improvement in mouse toxicity. All of the derivatized carbamates, with few exceptions, showed good insecticidal activity against houseflies, green rice leafhoppers and aphids in laboratory tests, though they were inferior to the parent methylcarbamate, carbofuran, on a weight basis. However, some derivatives were equally or more effective against these pests on a molar basis. Pot tests in greenhouse or field trials demonstrated that some of the derivatives were as effective as carbofuran even on a weight basis. Virtually all the derivatives tested were less effective inhibitors of acetylcholinesterase than carbofuran.

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Protective and curative antifungal activities of 16 1-[1-(2-substituted hydroxy-5-substituted phenyl)vinyl]imidazoles and 9 1-[2-(2-substituted hydroxy-5-substituted phenyl)-allyl]imidazoles were measured against Botrytis cinerea, a phytopathogenic fungus, under greenhouse conditions. A relationship between their antifungal activity in greenhouse conditions and that in vitro was examined quantitatively based on the regression analysis with the aid of physicochemical and structural parameters. The higher the in vitro activity, the higher the protective activity in greenhouse conditions. The protective activity was more persistent in the vinylimidazoles than in the corresponding allylimidazoles. The curative activity in greenhouse conditions increased as the activity in vitro increased. Substitution of the 2, 6-dichlorobenzyloxy group at the 2-position on the benzene ring was favorable to the curative activity. The curative activity does not seem to depend on the hydrophobicity of the molecule, because the positive effect of the log P term on the in vitro activity and the negative effect on the mobility within the leaf cancel each other.

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A concentration-acaricidal activity relationship of chloromethanesulfonamide (CMSA) against the carmine mite, Tetranychus cinnabarinus BOISDUVAL was examined by dipping cotton plant roots into CMSA solution. A relationship between CMSA concentration on/in the leaves and the acaricidal activity against the citrus red mite, Panonychus citri MCGREGOR, was also examined by foliar spray to mandarin orange trees. CMSA concentration in cotton leaves reached a peak 3 days after treatment and remained the same level thereafter. The acaricidal activity against the carmine mite increased gradually with time. By foliar spray CMSA concentration on/in the leaves declined rapidly as time elapsed, and so did the acaricidal activity. CMSA concentration in washed citrus leaves was at its highest 24hr after spraying. The acaricidal activity of CMSA against the citrus red mite was parallel to its concentration in the citrus leaves.

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N-Phenylcarbamates with various substituents on the benzene ring and at the ester moiety were prepared, and their fungicidal activity against Botrytis cinerea (gray mold of cucumber) and Cercospora beticola (cercospora leaf spot of sugar beet), which are resistant to benzimidazole fungicides, was determined by foliar application in pot tests. The 3, 4-diethoxy group on the benzene ring of methyl N-phenylcarbamates and the isopropyl group at the ester moiety of N-(3, 4-diethoxyphenyl) carbamates were favorable for high activity against B. cinerea. Modification of N-(3, 4-diethoxyphenyl) carbamates into thiocarbamate, urea and amide analogs and N-substitution with acyl and methyl groups resulted in reduced activity. Isopropyl N-(3, 4-diethoxyphenyl) carbamate (diethofencarb) showed systemicity and fungicidal activity against C. beticola as well as B. cinerea.

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A variety of carbamoylimidazoles were synthesized from 1, 2, 3, 4-tetrahydroquinolines, 1, 2-dihydroquinolines, benzomorpholines and 1, 2, 3, 4-tetrahydro-2-quinoxalinones and their herbicidal activity was examined. Substituents appeared to be important for their herbicidal activity. Highly active compounds were obtained when they were crowded around carbamoylimidazole linkages. Of these compounds, N-(2, 2-dimethyl-6-chloro-1, 2, 3, 4-tetrahydroquinoline) carbonylimidazole was tested against some weeds, and the test showed that it was a promising new herbicide with a wide spectrum.

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The release mechanism of DTP from pyrazolate [4-(2, 4-dichlorobenzoyl)-1, 3-dimethyl-5-pyrazolyl p-toluenesulfonate] suspensions and granules, and DTP granules was investigated by watching the change of DTP concentrations in paddy water and the residual pyrazolate in paddy soil 41 days after treatment in the early cultivation season of paddy rice (atmospheric temperature 9-31°C). It was found that the release of DTP was controlled by derivatizing DTP into pyrazolate. Pyrazolate granules released DTP in a more controlled manner than its suspension preparations. Among the granular pyrazolate formulations prepared in the same recipe which showed a good extention in paddy water, a sample containing pyrazolate of ca. 2.5m²/g of the specific surface area continued to release DTP for about 40 days. The release of DTP from such a granular sample was considered to take the following steps. 1) Reducing the water solubility by a factor of 90, 000 by derivatizing DTP into its tosylate, pyrazolate. 2) Promoting the dissolution rate of pyrazolate by minimizing the particle size of pyrazolate crystals. 3) Controlling the diffusion of pyrazolate into surrounding paddy water by appropriate disintegration of granules. 4) Controlling the formation of DTP by controlling the hydrolysis of pyrazolate. Such a granular pyrazolate sample can be one of release-control formulations developed by utilizing chemical and physical technologies.

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Bioaccumulation potency and biodegradation of pyrazolate [4-(2, 4-dichlorobenzoyl)-1, 3-dimethyl-5-pyrazolyl p-toluenesulfonate] and its hydrolysates, DTP [4-(2, 4-dichlorobenzoyl)-1, 3-dimethyl-5-hydroxypyrazole] and p-toluenesulfonic acid, were examined in guppies (Poecilia reticulata) and short-necked clams (Tapes philippinarum) using ¹⁴C-preparations. Uptake factors (UF: concentration of total ¹⁴C in aquatic organisms/concentration of a parent compound in test water) of pyrazolate in guppies at 0.33 and 32.3ppb treatment levels were about 590 and 290, respectively, whereas those of DTP and p-toluenesulfonic acid were 15 at 0.37ppb and less than 1 at 2.91ppb, respectively. UF values in clams were 52 for pyrazolate at 2.06ppb and 6.2 for DTP at 48.4ppb. On transference to clean water, ¹⁴C levels in the exposed aquatic organisms rapidly decreased, indicating that these chemicals and their metabolites did not bioaccumulate in the tested organisms. Pyrazolate was first metabolized through the hydrolysis of the ester linkage to give DTP and p-toluenesulfonic acid, followed by the oxidation at the 1- and 3-methyl groups of DTP and the cleavage of the benzoyl linkage into more polar compounds.

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The kinetic analyses for evaluation of the uptake and decomposition of pesticides by algae were pursued by using the green alga Selenastrum capricornutum and organophosphorus insecticides. The alga-induced disappearance rate constants (k_A) of fenitrothion, diazinon and cyanophos in each exponential growth stage, steady stage and whole growth period of algae were estimated independently of other disappearance rate constants originated from light and medium (k_ν, and k_M, respectively). The k_A values in the steady stage were 1.3-2.5 times larger than those in the exponential growth stage in all chemicals. The k_A values during the whole growth period were between those in the exponential growth stage and those in the steady stage, being closer to those in the steady stage. The k_ν and k_M values were also estimated for comparison in contribution for the disappearance.

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Degradation of diphenyl ether herbicides was studied in six soils under flooded conditions. The half-life periods largely varied depending on soil: 9 to 173 days for chlornitrofen (CNP), 3 to 87 days for nitrofen (NIP) and 8 to 64 days for chlomethoxynil, but the patterns and rates of the degradation were similar in a soil. No significant correlations were found between the degradation rates of the chemical and the physicochemical properties of the soils, while significant negative correlations were observed between the half-life periods of the chemicals and the soil redox potentials. The degradation of chlornitrofen was largely affected by the preincubation period of soil and the amendment of organic substances to soil. The herbicides were rapidly degraded at a lower redox potential of soil.

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Substituted phenyl alkanesulfonates were systematically synthesized and their insecticidal activity was measured. 3-Alkylthiophenyl alkanesulfonates, and their sulfoxide and sulfone derivatives exhibited insecticidal activity. Particularly, 3-n-propylthio, 3-iso-butylthio and their sulfone derivatives of the methanesulfonates showed remarkable insecticidal activity to such hoppers as Nephotettix cincticeps and Nilaparvata lugens. The methanesulfonate was most insecticidally active among various 3-n-C₃H₇S(O)_x-substituted phenyl alkanesulfonates. The sulfide and sulfoxide derivatives in 3-n-C₃H₇S(O)_x- and 3-iso-C₄H₉S(O)_x-substituted phenyl methanesulfonates showed low inhibitory activity to acetylcholinesterase in the homogenates of these two kinds of hopper, while sulfone derivatives showed high activity.

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The control efficacy of chloromethanesulfonamide (CMSA) against three species of mites was examined by using sprinkler spray, seed coating and trunk implantation methods. The control efficacy against citrus red mites was higher by spraying with a sprinkler than with gun because the chemical falling from leaves and trunks onto the soil surface is utilized again when absorbed into plants. On cotton seeds, a coating of CMSA at a. i. 2% concentration was proved capable to control carmine mites, and the control efficacy by group seeding was higher than by drill seeding. On trunk implantation, CMSA controlled sugi spider mites infesting Japanese cedars at the dosage of a. i. 4g/tree.

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Pheromone activity of synthetic periplanone-B (PB) was bioassayed in six species of genera Periplaneta and Blatta. The activity was very high in the males of P. americana and low in the males of P. japonica, P. brunnea, and B. orientalis. Attractivity of PB to the males of Periplaneta species was tested in houses at several locations. PB in traps attracted P. brunnea and P. japonica in addition to conspecific P. americana.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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A wide variety of toxicological studies on paraquat dichloride have been conducted in Japan to assess its safety. The results of these studies support the view that this herbicide will be safe if used following the recommended use instructions.

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[in Japanese]

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[in Japanese]

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