Mode of action of myomycin was examined by using Pseudomonas lachrymans, a causal pathogen of angular leaf spot of cucumber plants. The growth of Ps. lachrymans in liquid medium was strongly suppressed by adding the antibiotic at a concentration of 10μg/ml in the middle logarithmic stage of the bacterium. Exogenous respirations of the bacterial cells were inhibited about 60% at 200μg/ml of myomycin with pyruvate or acetate as substrates, but not with glucose, succinate or citrate. Incorporation of ¹⁴C-glucosamine into cell wall, ¹⁴C-acetate into lipid fraction, ¹⁴C-uridine into RNA and ¹⁴C-thymidine into DNA were not inhibited at a high concentration of 200μg/ml of the antibiotic. However, incorporation of ¹⁴C-phenylalanine into protein fraction was remarkably inhibited at 200μg/ml. Though exogenous respiration in the resistant strain of Ps. lachrymans was inhibited by the antibiotic as well as in the sensitive one, incorporation of ¹⁴C-phenylalanine into the protein fraction of resistant cells was not inhibited. These results indicated that the possible site of myomycin action against Ps. lachrymans might be in the process of protein biosynthesis.

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In the experiments on the fitness, reproduction rate in dicofol resistant and susceptible strain of the citrus red mite, Panonychus citri (McG.), of the same origin were compared at 25°C and 30°C. The reproduction rate in the resistant strain was lower than that in the susceptible one, especially, under higher temperature condition (30°C) or under a feeding condition on considerably damaged leaves of host trees. This was mainly caused by lower egg production in the resistant mites. The dicofol susceptibility of eggs in a mite population originally composed of a 1:1 mixture of resistant and susceptible strains of the same origin, was tested in 17 generations at 25°C. After 13 generations, the dicofol susceptibility of the mixed population increased remarkably. The result indicated that the resistant mites had lower values of fitness than the susceptible ones under either favorable (25°C) or unfavorable condition for reproduction of the spider mites in an acaricide-free environment. From the experimental data of the dicofol susceptibility of the mixed population, the relative value of fitness of the resistant mites was analyzed by a computer simulation. The experimental value best agreed with the calculated value, for which the relative value of fitness of the resistant mites was 0.75.

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(+)-Trans and (+)-cis isomers of phenothrin [3-phenoxybenzyl (±)-cis, traps-chrysanthemate] labeled with ¹⁴C at the methylene group of the alcohol moiety disappeared rapidly from the treated leaves of bean and rice plants with half-lives of less than one day under greenhouse conditions. On and/or in these plants, both isomers underwent ozonolysis at the isobutenyl double bond to yield ozonides of phenothrin isomers which were rapidly decomposed to the corresponding aldehydes and carboxylic acids. These ester products were further metabolized via cleavage of the ester linkage, hydroxylation at 2′- and 4′-positions of the alcohol moiety, and oxidation of benzyl alcohols to benzoic acids. The resulted alcohols and carboxylic acids were subsequently conjugated with sugars. Bean plant seedlings planted in Kodaira soil, Katano soil and Muko sand treated with 1.0ppm of ¹⁴C-phenothrin isomers took up very little ¹⁴C into shoots, and pods and seeds, whereas roots retained 0.21-3.48ppm of ¹⁴C. No parent compounds were detected in shoots. ¹⁴C-Phenothrin isomers were rapidly decomposed in Kodaira and Katano soils with half-lives of 1 to 2 days under upland conditions. On the other hand, degradation of both isomers was much slower under flooded conditions, and half-lives were 2 to 4 weeks and 1 to 2 months for the (+)-trans and (+)-cis isomers, respectively. Degradation of phenothrin isomers in the soils proceeded via cleavage of the ester linkage, hydroxylation at 4′-position of the alcohol moiety, cleavage of the diphenyl ether linkage and oxidation of benzyl alcohols to benzoic acids. These products were not persistent in the soils under both conditions and the labeled carbon was finally decomposed to ¹⁴CO₂.

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A polynomial expression which gives the change in concentration of elute was derived for soil column system in which pesticide solution was added at constant concentration. The polynomial was composed of a theoretical plate number P of soil column, adsorption ratio G for the soil, and distance moved by the solution expressed by imaginary plate number n. The curve has an inflexion point except when G is small or P is unit. P is estimated from the inflexion point n_i, which is calculated from the observed inflexion point using the water capacity of the column and a volume of unit fraction. A constant value of approximately 12g as soil weight per unit plate was obtained with picric acid using soil columns with different weights of a volcanic ash soil. Chlorate showed no adsorption on the soil and gave no physically significant P value. Pentachlorobenzoic acid gave a small G value (0.5) indicating that the amount of soil used in the assaying was too small to give any physically significant P value. An apparatus to supply a constant flow rate of water was devised.

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The theoretical plate number of soil column (Nishigahara, volcanic ash soil) for elution of several chemicals were determined. Leaching curve of dichromate showed a very slow rise in early stage and a rapid rise later on. Phosphate gave a very slow rise and no plateau on the leaching curve. These imply that the soil may be saturated by these chemicals before giving a normal leaching curve. Dimethyl hydrogen phosphate had an unusual adsorption ratio which showed a tendency to increase with an increase in the amount of solute. As this chemical was hardly extracted with organic solvent from the aqueous solution, it was successfully determined by adsorption on anionic exchange resin and extraction with hydrochloric acidic acetone. But the determination of dimethyl hydrogen phosphate in soil was still difficult. These three chemicals did not give any physically significant plate numbers. Adsorption of dimethoate was too small to give a physically significant plate number. Trichlorfon showed a normal leaching curve but the plateau was low, implying the loss during the leaching test. The soil weight per unit plate was 12g for elution of trichlorfon. The leaching curves of p-nitrophenol, p-nitrobenzaldehyde and p-nitroanisole were normal and the soil weight per unit plate was 4-6g. The theoretical formula were not always satisfied in all cases because these had many factors other than physical adsorption.

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Metabolic fate of fenvalerate [α-cyano-3-phenoxybenzyl-2-(4-chlorophenyl) isovalerate] and the [S]-acid ester isomer in bean plants was studied under laboratory conditions. When fenvalerate and the [S]-acid isomer were each applied to the leaf surface of bean plants at a rate of 10μg per leaf, both compounds similarly disappeared from the treated leaves with half-lives of approximately 14 days. On and/or in the plants, fenvalerate and the [S]-acid isomer underwent decarboxylation, ester cleavage, hydrolysis of the CN group to CONH₂ and COOH groups, hydroxylation at 2′- and 4′-phenoxy positions, conversion of the alcohol moiety to 3-phenoxybenzyl alcohol and 3-phenoxybenzoic acid, and conjugation of the resulting carboxylic acids and alcohols with sugars. Very little of ¹⁴C was transferred to other parts of the bean plants. When bean plant seedlings were planted for 30 days in Kodaira light clay and Katano sandy loam soils treated with 1.0ppm of ¹⁴C-fenvalerate, roots retained fairly large amounts of ¹⁴C, shoots, pods and seeds contained very little ¹⁴C. No parent compound was detected in shoots.

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On exposure to sunlight, fenvalerate [α-cyano-3-phenoxybenzyl-2-(4-chlorophenyl) isovalerate] was rapidly decomposed in distilled water, 2% aqueous acetone, river and sea water to almost the same extent. The half-life of fenvalerate photodegradation in each aqueous suspension ranged from ca. 4 days in summer to 13-15 days in winter, due to seasonal variation of sunlight intensity. The quantum yield was determined to be 6.8×10^-3 (at 313nm in water), and the half-life of disappearance at 40 degree North Latitude was calculated to be 4.1 days and 12.4 days in summer and in winter, respectively. On soil surface, the rate of photodegradation was different depending on the soil used, with half-lives of approximately 2, 6 and 18 days in Kodaira light clay, Azuchi sandy clay loam and Katano sandy loam soils, respectively. Without sunlight, approximately 55 to 83% of the applied fenvalerate remained on these soils 20 days post-treatment. Fenvalerate was photodecomposed by oxidation, decarboxylation, hydration at CN group to CONH₂, cleavage of ester or diphenyl ether linkage, hydrolysis from CONH₂ to COOH. Hydrogen cyanide was also liberated in water and promptly transformed to carbon dioxide by natural sunlight. The predominant reactions were decarboxylation and cleavage of ester linkage in water, whereas hydration at CN group was dominant on soil surface. Thus, photodegradation rates and pathways for fenvalerate were somewhat dependent on the environmental conditions tested.

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Effect of a new systemic bactericide, techlofthalam [N-(2, 3-dichlorophenyl)-3, 4, 5, 6-tetrachlorophthalamic acid], against bacterial leaf blight of rice plants was evaluated by means of several test methods in the greenhouse. Techlofthalam showed no activity against Xanthomonas oryzae, the causal bacterium in vitro when estimated with a turbidimetric method. Soil application of techlofthalam at the dosages of 0.3 and 0.6g/m² showed considerable effectiveness for inhibiting lesion formation and development, though the effect somewhat delayed after application. It was elucidated by the experiments relating to foliage application that the agent had poor preventive and curative action for control of lesion formation in the inoculated leaves, and that it gave an excellent control effect against lesion development with a spray inoculation method though it was fairly poor with a needle prick method. Techlofthalam showed no plant physiological activity to any of plants tested by means of foliage application and pre-emergence soil drench.

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Techlofthalam [N-(2, 3-dichlorophenyl)-3, 4, 5, 6-tetrachlorophthalamic acid] was evaluated as a rice bacterial leaf blight control agent in the field. Techlofthalam was highly effective at the dosage of 4kg (a. i.) by soil application and of 60 to 120g by foliage application per hectare. Foliage application showed an excellent residual effect for suppressing lesion development and also effective against the disease on rice plants damaged by an artificial storm despite of poor effectiveness by a needle prick inoculation method in the greenhouse.

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Adsorption isotherms of isoprothiolane with soils were approximated to be a straight line (Henry's type adsorption). Although this process was exothermic, the heat of adsorption was very low and in the range of 4.3-6.0kcal/mol. Such low heat suggests that the soil adsorption of isoprothiolane can be categorized as a physical one. The movement of isoprothiolane in soils with water was observed to vary inversely as the extent of adsorption. There was a good correlation between the mobility and adsorption of isoprothiolane in soils. The uptake of applied isoprothiolane by rice plants was found to reduce in the presence of soils.

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Direct determination of cyclohexyltin derivatives by atomic absorption spectrophotometry with a graphite furnace atomizer (GFAA) was developed and this method was applied to residue analysis of tricyclohexyltin hydroxide in green tea and orange sprayed PLICTRAN miticide. Hitachi 170-70 type FGAA using the ZEEMAN EFFECT for the back ground correction was used. Analytical line was 286.3nm and Argon as sheath gas was used at flow rate of 3 liter/min. Ten μl of sample solution was introduced into the graphite furnace by Eppendorf pipette. Four cyclohexyltin derivatives, tetracyclohexyltin (Cy₄Sn), tricyclohexyltin hydroxide (Cy₃SnOH), dicyclohexyltin oxide (Cy₂SnO), monocyclohexylstannoic acid (CySnOOH) and inorganic tin were investigated on their operating conditions in the graphite furnace. The ashing condition by which the organotin was completely decomposed to inorganic form was seemed to be affected by its chemical and physical properties. Calibration curves were linear up to 3ng tin and relative standard deviation at ten times determinations were below 5% for all compounds. Lower limit of detection which gave 0.005 absorbance were 0.5ng tin for monocyclohexylstannoic acid and 0.2ng tin for the others. Tricyclohexyltin hydroxide in green tea or orange was extracted with n-hexane and acetic acid. The residue was purified by following column chromatography. Basic alumina (3.5g, activity grade I) was packed into column (300×15mm I·D). After the sample had passed through, the column was developed with 50ml of n-hexane, 50ml of ether (tetracyclohexyltin was eluted in these fractions) and 20ml of ethanol containing 2% benzene. Tricyclohexyltin hydroxide was eluted in the last fraction and monocyclohexylstannoic acid and dicyclohexyltin oxide still remained on the alumina. The solution was evaporated and the residue was dissolved in n-hexane, then determined by GFAA. The operating conditions were as follows, Drying: 100°C, 20sec; Ashing: 900°C, 60sec; Atomization: 2, 800°C, 5sec. The lower limits of detection were 0.05ppm in 5g of green tea, 0.01ppm in 20g of orange peel and 0.006ppm in 50g of orange flesh and orange juice. Recoveries from green tea (fortified at the 2.0ppm level), orange flesh (0.1ppm), orange peel (0.3ppm) and orange juice (0.1ppm) were 91, 94, 82 and 109%, respectively. No acid digestion and a series of solvent extraction step were required for this analysis.

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Green rice leafhoppers, Nephotettix cincticepts Uhler, collected at five locations within 15km² area in central Taiwan were tested by topical application method for their susceptibility to vamidothion. Populations from Shu-wang and Hsiang-lu showed definite resistance to this chemical when compared with the reference population. The acetylcholinesterase of the most resistant Hsiang-lu population (resistance ratio 26.3) was 4-fold less sensitive to vamidothion than that of the reference population. Electrophoretic study revealed that one extra band with strong aliesterase activity and moderate cholinesterase activity appeared only in Wu-fu population, which had a resistance ratio of 4.5, and yet acetylcholinesterase most sensitive to the inhibition by this insecticide.

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Metabolites of diuron, methazole and linuron formed by mouse microsomal oxidases were analyzed with a chloroplast/2, 6-dichlorophenolindophenol system for visualizing Hill reaction inhibitors on tlc plates and in the first two cases with ¹⁴C-labeled substrates. Each compound yields 3, 4-Cl₂-φ-NHC(O)NHCH₃ and other metabolites potent as Hill reaction inhibitors. N-Methyl hydroxylation and subsequent oxidation or dealkylation yield 3, 4-Cl₂-φ-NHC(O)R metabolites where R is: -N(CH₃)CH₂OH, -N(CH₃)CHO, -N(CH₂OH)₂, -NHCH₃, -NHCH₂OH, -NHCHO and -NH₂ from diuron; -N(CH₂OH)OCH₃ and -NHOCH₃ from linuron. Other reactions involve oxidative N-demethylation of methazole, oxidative O-demethoxylation of linuron, and reductive cleavage of methazole, the latter two reactions yielding 3, 4-Cl₂-φ-NHC(O)NHCH₃. Another oxidative metabolite of diuron and cleavage product of methazole is the isourea-N-oxide, 3, 4-Cl₂-φ-N(O)=C(OH)NHCH₃.

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The fate and behaviors of the herbicide benthiocarb (Saturn^®, S-4-chlorobenzyl N, N-diethylthiocarbamate) in mice, plants, soils and river water were studied in the laboratory and fields. ¹⁴C-Benthiocarb was absorbed from the gastrointestinary tract of mice, rapidly metabolized and excreted into the urine. The compound was absorbed through the roots and stalks of rice plants and barnyardgrass and rapidly metabolized. The degradation of benthiocarb in soil was faster under aerobic conditions than anaerobic conditions. Photochemical decomposition also occurred rapidly. The major degradation pathways were common in the different biota and under light, and occurred through deethylation, hydrolysis and oxidation. The main products, however, differed according to the biota and light. The other routes of degradation also existed. The volatilization of benthiocarb occurred rapidly from the aqueous solution, but the rate decreased markedly by existence of soil in the solution due to the rapid adsorption to the soil. The volatilization from the surface of unflooded soil was very slow. The amount of benthiocarb in surface water, soil and crop plants decreased rapidly in fields treated with the herbicide. The residual amounts in cereals, begetables and other crops were very small. Seasonal changes in benthiocarb concentration in creek and river water were also studied. The positive correlation existed between the concentration and the applied amount and term.

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The efficient applications of pesticide have been developed and diffused since 1953.
1. The spray by long size boom nozzle was tested against rice stem borer, Chilo suppressalis, with parathion E. C. in 1954. The spray was obtained effective results better than spray by conventional spray nozzle.
2. The physical properties of dust was studied for aerial dusting with helicopter from 1966 to 1972. The flower bility from duster of helicopter was obtained proportionally results to angle of slope and inproportionally to bulk density. The physical properties for check of large coagulative dust were dispersibility by Ueda method, 20-40.
3. We examined the relation between the efficiency of dusters with boom type below head and the physical properties of dust. When the dispersibility became larger, the remaining quantity of dusts inside the boom decreased. The dusts were inclassified usually to high and low content of active ingredient. Against pestes of rice plant, the effects of dusting with 20, 55 and 110 meters long boom were the same as conventional dusting.
4. The aerial ULV spray was studied by the small apparatus we developed from 1965 to 1970. For the ULV spray many pesticides was used for the control of major diseases and insect pests of rice plant. The pesticides obtained good effectiveness against major pests was malathion, fenitrothion, Kasugamycin of antibiotic etc. The registration of these pesticides was accepted in 1969, and aerial ULV spray developed covering more than about 0.6 million hectares of farm land and forest area in 1979.
5. The new granules was studied against major pests of rice plant from 1968 to 1973. The fine micro-granul (62-210μ) was selected best granul pesticide against major pests of rice plant in 1973.
6. A new method, low volume application by fine dust formulations in green houses has been developed. The formulations whose mean diameters were under 5μ were applied at the rate of 300-500g/10 a from the entrance of green house by knapsack-type power applicator. The registration of several pesticides using this new method was accepted in 1979.
7. The pest control by foam spray was studied for safty spray method from 1973 to 1975. The foam spray is used by few pesticides in 1978.

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