Differential Vertical Movement of Nonvolatile Nematicides in Soil

When incorporated in the top 5-cm of Tifton sandy loam at 11.2 kg/ha in the field, B-68138 [ethyl 4-(methylthio)-m-tolyl isopropyl phosphoramidate] prevented galling of tomato roots by Meloidogyne sp. down to 20 cm. A similar application of 16.8 kg/ha of V-C 9-104 [0-ethyl S,S-dipropyl phosphorodithioate] was 99% effective down to 20 cm. Aldicarb [2-methyl-2-(methylthio) propionaldehyde 0-(methylcarbamoyl) oxime], B-25141 [0,0-diethyl 0-{p-(methylsulfinyl) phenyl}phosphorothioate], and carbofuran [2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate] prevented galling only in the zone of incorporation (top 5-cm of soil). When aldicarb (11.2 kg/ha) was applied to the surface of Ontario fine sandy loam contained in clay pots in the greenhouse, it prevented galling of tomato roots down to 20 cm deep. V-C 9-104 and B-68138, applied similarly, were 100% effective to a depth of 5 cm. B-25141 was 100% effective in the zone of incorporation only. D-1410 [S-methyl-l-(dimethylcarbamoyl)-N-l(methylcarbamoyl)oxy] thioformimidatel did not control 100% of the root-knot nematodes at any depth.     

Comparison of Millet and Sorghum-Sudangrass Hybrids Grown in Untreated Soil and Soil Treated with Two Nematicides

Aldicarb and Bay 68138 (ethyl 4-(methylthio)-m-tolyl isopropylphosphoramidate) were effective in increasing the plant height and yield of millet and sorghum-sudangrass hybrids. Stunting of plants and reduction in yield were inversely proportional to the number of Pratylenchus spp. and Belonolaimus longicaudatus present in the rhizosphere. Millet and sorghum-sudangrass hybrids supported large numbers of Criconemoides ornatus, Pratylenchus spp., B. longicaudatus, and Xiphinema americanum. Funk''s sorghum × sudangrass Hybrid 78 was more sensitive to injury by the nematode complex than were Tift 23A × 186 or Gahi-I pearl millet. ''Tiflate'' pearl millet was more resistant than other millets or sorghums to injury caused by C. ornatus, Pratylenchus spp., Trichodorus christiei, and B. longicaudatus. Millet and sorghum-sudangrass hybrids are poor summer cover crops because they favor intensive development of P. brachyurus, P. zeae, T. christiei, and B. longicaudatus.     

The Relationship Between Tobacco Yield and Time of Infection with Meloidogyne javanica

Yield of tobacco was related to the amount of infection by Meloidogyne javanica during the first month after transplanting. Six nematicidal treatments significantly reduced infection during this period and subsequently increased yield. However, during the second month after transplanting, infection in plots treated with O-ethyl S,S-dipropyl phosphorodithioate (V-C 9-104) and a mixture of 80% chlorinated C₃ hydrocarbons + 20% methyl isothioeyanate (DD + MENCS) was not significantly different from infection in untreated plots. After 3 months, root-knot indices in plots treated with V-C 9-104, DD + MENCS, O,O-diethyl O-[p-(methylsulfinyl) phenyl] phosphorothioate (B-25141), and 1,3-dichloropropene, 1,2-dichloropropane (DD) were not significantly different from those in untreated plots; reduced infection was present only in plots treated with ethylene dibromide (EDB) and 2-methyl-2 (methylthio) propionaldehyde O-(methylcarbamoyl) oxime (aldicarb). At the end of harvest (4 months after transplanting), root-knot indices in all plots were essentially equal.     

Control of Heterodera schachtii with Foliar Application of Nematicides

Foliar applications of ethyl 4-(methylthio)-m-tolyl isopropylphosphoramidate (phenamiphos) or S-methyl 1-(dimethylcarbamoyl)-N-[(methylcarbamoyl)oxy] thioformimidate (oxamyl) retarded infection of sugarbeets by the sugarbeet nematode, Heterodera schachtii under greenhouse conditions. Maximum nematode control was obtained when treatments were applied previous to, or at the time of, inoculation of plants with the nematode. Consecutive foliar applications inhibited nematode development, with four applications giving greatest inhibition of maturation. A treatment with either phenamiphos or oxamyl at 2,000 μg/ml (ppm) resulted in the greatest increase in plant growth, and 4,000 μg/ml gave the best nematode control. A treatment of 4,000 μg/ml of either phenamiphos or oxamyl was phytotoxic. However, this was due to container confinement of the chemical since phytotoxicity at this rate has not been observed under field conditions.     

Pinto Bean Yield Increased by Chemical Control of Pratylenchus spp.

Pinto bean yields and Pratylenchus spp. (nematode) population densities are reported for field plots pro-plant treated with nematicides in 1966 and 1968. Vidden-D (1,3-dichloropropene, 1,2-dichloropropane and related chlorinated hydrocarbons), Vortex (20% methyl isothioeyanate plus 80% chlorinated Ca-hydrocarbons), Telone PBC (80% dichloropropenes, 15% chloropicrin, and 5% propargyl bromide), Dasardt (0,0-Diethyl 0-[p-(methylsulfmyl)phenyl] phosphorothioate, and Dowfume MC-2 (98% methyl bromide plus 2% chloropierin) were used in 1966. Vorlex, Dasanit, and D-D (1,3-dichloropropene, 1,2-dichloropropane and related chlorinated hydrocarbons) were each used at two rates in 1968.Fumigated plot yields ranged 32-56% higher than control plots in 1966 and 11-80% higher in 1968. Significant yield increases were obtained for all fumigants except Telone PBC in 1966. In 1968 significant increases were obtained from use of the high rate (374 liters/ha) of Vorlex and low rate (8.4 liters/ha) of Dasanit. There was an inverse relationship between yield and numbers of Pratylenchus spp./g root on four sampling dates in 1968. A correlation coefficient of -.39 (P ≤ 0.05) was obtained for samples taken 36 days after planting and -.52 (P ≤ 0.01) for samples taken 30 days later. There was no significant correlation between yield and numbers of Pratylenchus spp. recovered from the soil.     

Control of potato cyst-nematodes, Heterodera rostochiensis and H. pallida, in sandy, peaty and silt loam soils by oximecarbamate and organophosphate nematicides

Small amounts (5.6 or n-2 kg a.i./ha) of aldicarb or oxamyl, incorporated in the soil before potatoes were planted in spring, controlled potato cyst-nematodes (Heterodera rostochiensis and H. pallida) on susceptible cultivars equally well in sandy, peaty and silt loam soils. In soils treated with either nematicide, nematode numbers increased little or decreased; in untreated soils nematode numbers increased greatly. In contrast organophosphate nematicides, similarly applied, fenamiphos (proposed BSI common name for O-ethyl-O-(3-methyl-4-methylthiophenyI)-isopropylamido-phosphate), ethoprophos (proposed BSI common name for (O-ethyl S, 5-dipropyl phos-phorodithioate), CGA 12223 (O, O-diethyl O-[i-isopropyl-5-chloro-i,2,4-triazoIyl-(3)] phosphorothioate) and Dowco 275 (O, O-diethyl O-(6-fluoro-2 pyridyl) phosphorothioate), were ineffective at one or more of the experimental sites. Potato yields were greatly increased by oximecarbamate or organophosphate nematicides only in soils heavily infested with the nematodes.     

Desulfuration of Dialkyl Thiophosphoric Acids by a Pseudomonad

A strain of Pseudomonas acidovorans used the organophosphorus pesticide breakdown products, ionic O,O-diethyl phosphorothioate and ionic O,O-diethyl phosphorodithioate, as sulfur sources. The growth yields from the thiophosphates and sulfate were 3.6 to 4.1 kg of protein per mol of sulfur. Elemental sulfur and sulfide also served as sulfur sources but gave lower growth yields.     

Salicylanilide diethyl phosphates as cholinesterases inhibitors

Based on the presence of dialkyl phosphate moiety, we evaluated twenty-seven salicylanilide diethyl phosphates (diethyl [2-(phenylcarbamoyl)phenyl] phosphates) for the inhibition of acetylcholinesterase (AChE) from electric eel (Electrophorus electricus L.) and butyrylcholinesterase (BChE) from equine serum. Ellman’s spectrophotometric method was used. The inhibitory activity (expressed as IC₅₀ values) was compared with that of the established drugs galantamine and rivastigmine. Salicylanilide diethyl phosphates showed significant activity against both cholinesterases with IC₅₀ values from 0.903 to 86.3 μM. IC₅₀s for BChE were comparatively lower than those obtained for AChE. All of the investigated compounds showed higher inhibition of AChE than rivastigmine, and six of them inhibited BChE more effectively than both rivastigmine and galantamine. In general, derivatives of 4-chlorosalicylic acid showed enhanced activity when compared to derivatives of 5-halogenated salicylic acids, especially against BChE. The most effective inhibitor of AChE was O-{5-chloro-2-[(3-bromophenyl)carbamoyl]phenyl} O,O-diethyl phosphate with IC₅₀ of 35.4 μM, which is also one of the most potent inhibitors of BChE. O-{5-Chloro-2-[(3,4-dichlorophenyl)carbamoyl]phenyl} O,O-diethyl phosphate exhibited in vitro the strongest inhibition of BChE (0.90 μM). Salicylanilide diethyl phosphates act as pseudo-irreversible cholinesterases inhibitors.     

Corn Response to Subsoiling and Nematicide Application

A 2-year field study evaluated the influence of subsoiling and nematicide application, alone and in combination, on the growth and yield of field corn in a sandy soil in north-central Florida. The field had a 25-30-cm-deep tillage pan (plowpan) and was infested with Belonolaimus longicaudatus, Hoplolaimus galeatus, Trichodorus christei, and Pratylenchus spp. Subsoiling increased corn yield both years, and the residual effect of subsoiling in the first year increased yields in the second year. Preplant application of DD injected in-row increased yields and reduced nematode populations. At-planting applications of DD injected in-row and carbofuran in-furrow or in a band were less effective than subsoiling in increasing yields and reducing nematode numbers. Interactions between subsoiling and nematicide treatments occurred in the second year.     

Managing Nematode Population Densities on Tomato Transplants Using Crop Rotation and a Nematicide

Millet, milo, soybean, crotalaria, and Norman pigeon pea were used in conjunction with clean fallow and a nematicide (fensulfothion) for managing nematode populations in the production of tomato transplants (Lycopersicon esculentum Mill.). Glean fallow was the most effective treatment in suppressing nematode numbers. After 2 years in tomato, root-knot nematodes increased in numbers to damaging levels, and fallow was no longer effective for complete control even in conjunction with fensulfothion. After 4 years in tomato, none of the crops used as summer cover crops alone or in conjunction with fensulfothion reduced numbers of root-knot nematodes in harvested tomato transplants sufficiently to meet Georgia certification regulations. Milo supported large numbers of Macroposthonia ornata and Pratylenchus spp. and crotalaria supported large numbers of Pratylenchus spp. Millet, milo, soybean, crotalaria, and pigeon pea are poor choices for summer cover crops in sites used to produce tomato transplants, because they support large populations of root-knot and other potentially destructive nematodes.     

Control of the Lance Nematode,Hoplolaimus galeatus,on 'Tifdwarf' Bermudagrass by Chemical Dips

Dipping of bare-rooted ''Tifdwarf'' bermudagrass sprigs in 1000 ppm of the 2,4-dichlorophenyl ester of methanesulfonic acid plus 2150 ppm 1,2-dibromo-3-chloropropane or in 1000 ppm ethyl 4-(methylthio)-m-tolyl isopropyl phosphoramidate for 30 min eliminated Hoplolaimus galeatus (Cobb) Thorne. No phytotoxic effect was observed and bermudagrass growth was improved.     

Com Yield Increases Relative to Nonfumigant Chemical Control of Nematodes

Corn yields were measured after application of nematicides in 16 experiments, mostly in medium-to-heavily textured soil, at 12 locations in Iowa during 1973-1976. The average maximum yield increase in plots treated with nematicides was 21% over yields in untreated plots. Yields were correlated negatively with nematode numbers or nematode biomass in nearly all comparisons. Correlations of nematode numbers in the soil with yield averaged -0.56 for Helicotylenchus pseudorobustus, -0.45 for Hoplolaimus galeatus, -0.51 for Pratylenchus spp., and -0.64 for Xiphinema americanum. Correlation coefficients for numbers of nematodes in the roots and yield averaged -0.63 for Pratylenchus spp. and -0.56 H. galeatus. Correlation coefficients for yield and total number of nematodes averaged -0.65 in roots and -0.55 in soils. Negative correlations also were greater for comparisons of yield with total parasitic-nematode biomass than with numbers of individual nematodes of a species or total numbers of parasitic nematodes.     

Synthèse de trithioorthocarbonates de pyranosides par thermolyse de bis(dithiocarbonates)

The thermal decomposition of methyl 4,6-O-benzylidene-2,3-di-O-[(methylthio)-thiocarbonyl]-α-d-glucopyranoside afforded methyl 4,6-O-benzylidene-2-thio-α-d-mannopyranoside 3-O,2-S-(S,S-dimethyl trithioorthocarbonate) and methyl 4,6-O-benzylidene-3-thio-α-d-allopyranoside 2-O,3-S-(S,S-dimethyl trithioorthocarbonate) in good yield. This decomposition can be generalized to 1,3-diols derived from sugars. Thus methyl 2,3-di-O-methyl-4,6-di-O-[(methylthio)thiocarbonyl]-α-d-glucopyranoside afforded in the same way the corresponding trithioorthocarbonates, following a regioselective process. The structures of these trithioorthocarbonates are confirmed by spectral and chemical proofs.     

DPMA,a deoxypodophyllotoxin derivative,induces apoptosis and anti-angiogenesis in non-small cell lung cancer A549 cells

We found that the deoxypodophyllotoxin derivative, 2,6-dimethoxy-4-(6-oxo-(5R,5aR,6,8,8aR,9-hexahydrofuro[3′,4′:6,7]naphtho[2,3-d][1,3]dioxol-5-yl)phenyl ((R)-1-amino-4-(methylthio)-1-oxobutan-2-yl)carbamate (DPMA), exhibited superior cytotoxicity compared with etoposide. In this study, we investigated the mechanism of action of DPMA. DPMA exhibited anti-proliferative activity and induced apoptosis in A549 cells in a dose- and time-dependant manner. DPMA inhibited microtubule formation and induced expression of Bax, cleaved caspase-3, p53 and ROS, and inhibited Bcl-2 expression. DPMA also affected cyclinB1, cdc2 and p-cdc2 expression, inducing cell cycle arrest. DPMA also inhibited tube formation of VEGF-induced human umbilical vein endothelial cells. These studies demonstrate that DPMA inhibits p53/cdc2/Bax signaling, thereby inhibiting cell growth/angiogenesis and inducing apoptosis.     

The synthesis of antigenic determinants for yeast d-mannan,and a linear (1→6)-α-d-gluco-d-mannan,and their protein conjugates

2-O-Benzoyl-3,4,6-tri-O-benzyl-1-O-tosyl-d-mannopyranose and 2,3,4-tri-O- benzyl-6-O-(N-phenylcarbamoyl)-1-O-tosyl-d-glucopyranose were allowed to react with partially blocked 2-[4-(p-toluenesulfonamido)phenyl]ethyl α-d-manno- and -gluco-pyranosides. Disaccharides having α-d-Manp-(1→2)-α-D-Manp, α-d-manp-(1→6)-α-d-Manp, α-d-Manp-(1→6)-α-d-Manp, and α-d-Glcp-(1→6)-α-d-Manp structures, and a branched trisaccharide having the structure α-d-Manp-(1→2)-[α-d-Manp-(1→6)]-α-d-Manp were synthesized. The oligosaccharides were deblocked with sodium in liquid ammonia to give glycopyranosides having a free primary aromatic amine which were converted into isothiocyanate derivatives with thiophosgene. The functionalized oligosaccharides were then coupled to bovine serum albumin to give protein conjugates.     

Synthesis and pharmacological studies of new pyrazole analogues of podophyllotoxin

The pyrazole analogues of podophyllotoxin were synthesized by the chalcone route. This route attracts the attention because of its simple operating conditions and easy availability of the chemicals. Initially, benzylideneacetophenones (chalcones) were prepared in high yields by Claisen-Schmidt reaction of acetophenones with 4-(methylthio)benzaldehyde. The cyclopropyl ketones were prepared in good yields by the reaction of chalcones with trimethylsulfoxonium iodide. Tetralones were prepared in good yields by the Friedel-Craft’s intramolecular cyclization reaction of cyclopropyle ketones in the presence of anhyd. stannic chloride and acetic anhydride. The tetralones on formylation to give substituted hydroxylmethylene tetralones. Condensation of substituted hydroxylmethylene tetralones with hydrazine hydrate afforded target compounds. The structures of the synthesized compounds were confirmed by IR, ¹H NMR and Mass spectral technique. The title compounds were screened for their antimitotic and antimicrobial activities. Among the synthesized compounds cyclopropyl ketones and pyrazole analogues of podophyllotoxin, compound 7-(methylthio)-5-(4-(methylthio)phenyl)-4,5-dihydro-² H-benzo[g]indazole is more active than 5-(4-(methylthio)phenyl)-4,5-dihydro-² H-benzo[g]indazole, 7-methyl-5-(4-(methylthio)phenyl)-4,5-dihydro-² H-benzo[g]indazole, 7-methoxy-5-(4-(methylthio)phenyl)-4,5-dihydro-² H-benzo[g]indazole and the key intermediate tetralones in 100, 200 and 400 ppm at 12, 18 and 24 h and also showed very good activity against screened bacteria and fungi compared to their standard.     

Laboratory and field tests in 1966-67 on chemical control of wireworms (Agriotes spp.)

Of sixteen compounds applied to soil in laboratory tests, azinphos-ethyl, P2188 (O,O-diethyl S-chloromethyl phosphorothiolothionate), ‘Dursban’ (O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate), P1973 (S-(N-methoxycarbonyl-N-methylcarbamoylmethyl) dimethyl phosphorothiolothionate), B77488 (O,O-diethylphosphorothioate O-esterwith phenylglyoxylonitrile oxime) and R42211 (O,O-diethyl O-(2-diethylamino-6-methyl-pyrimidin-4-yl) phosphorothioate) killed wireworms when first tested, but in second tests with the same soils only ‘Dursban’, P2188 and B77488 did so. Treating seeds with ‘Dyfonate’ (O-ethyl S-phenyl ethyl phosphonodithioate) or with ethion/γ-BHC mixtures killed few wireworms. Three field trials compared the organophosphorus insecticides ‘Dursban’, ‘Dyfonate’ and phorate with organochlorine standards. In trials with barley and potatoes the standard was 3 lb a.i./acre (3·36 kg/ha) of aldrin. The organophosphorus compounds increased plant stands of barley almost as much as aldrin, although they killed fewer wireworms; and they protected fewer potato tubers from wireworm damage. The third trial compared the organophosphorus compounds with 0·5 lb a.i./acre (0·56 kg/ha) γ-BHC sprayed on a site drilled with sugar beet seed dressed with dieldrin. The γ-BHC increased plant stands almost as much as did 3 lb a.i./acre of the organophosphorus insecticides, and killed as many wireworms.     

Spatial Distribution of Plant-Parasitic Nematodes in Semi-Arid Vitis vinifera Vineyards in Washington

The most commonly encountered plant-parasitic nematodes in eastern Washington Vitis vinifera vineyards are Meloidogyne hapla, Mesocriconema xenoplax, Pratylenchus spp., Xiphinema americanum, and Paratylenchus sp.; however, little is known about their distribution in the soil profile. The vertical and horizontal spatial distribution of plant-parasitic nematodes was determined in two Washington V. vinifera vineyards. Others variables measured in these vineyards included soil moisture content, fine root biomass, and root colonization by arbuscular mycorhizal fungi (AMF). Meloidogyne hapla and M. xenoplax were aggregated under irrigation emitters within the vine row and decreased with soil depth. Conversely, Pratylenchus spp. populations were primarily concentrated in vineyard alleyways and decreased with depth. Paratylenchus sp. and X. americanum were randomly distributed within the vineyards. Soil water content played a dominant role in the distribution of fine roots and plant-parasitic nematodes. Colonization of fine roots by AMF decreased directly under irrigation emitters; in addition, galled roots had lower levels of AMF colonization compared with healthy roots. These findings will help facilitate sampling and management decisions for plant-parasitic nematodes in Washington semi-arid vineyards.     

Synthesis of phenyl O-α-l-fucopyranosyl-(1→2)-O-β-d-galactopyranosyl-(1→3)-2-acetamido-2-deoxy-α-d-galactopyranoside

phenyl 2-acetamido-2-deoxy-4,6-O-(p-methoxybenzylidene)-3-O-[4,6-O-(p-methoxybenzylidene)-β-d-alactopyranosyl]-α-d-galactopyranoside (3) was prepared from phenyl 2-acetamido-2-deoxy-4,6-O-(p-methoxybenzylidene)-3-O-(2,3,4,6-tetra-O-acetyl-β-d-galactopyranosyl)-α-d-galactopyranoside by zemplén deacetylation, followed by reaction with p-methoxybenzaldehyde in the presence of anhydrous zinc chloride. The selective benzoylation of 3 gave the 3′-benzoate which, on condensation with 2,3,4-tri-O-benzyl-α- l-fucopyranosyl bromide under catalysis by halide ion, afforded a crystalline trisaccharide from which the title trisaccharide was obtained by debenzoylation followed by catalytic hydrogenolysis.     

Seasonal Population Dynamics of Selected Plant-Parasitic Nematodes on Four Monocultured Crops

Seasonal fluctuations in field populations of Meloidogyne incognita, Pratylenchus zeae, P. brachyurus, Criconemoides ornatus, Trichodorus christiei, and Helicotylenchus dihystera on monocultured corn, cotton, peanut, and soybean were determined monthly for 4 yr. Population densities of M. incognita were greater in corn and cotton plots than in peanut and soybean plots from July until January. Those of Pratylenchus spp. were greater on corn and soybean than on cotton and peanut during all months except May and June. C. ornatus populations were greater on corn and peanut than on cotton and soybean during all months. C. ornatus on corn and peanut was more numerous in July than in other months. There was no significant increase in populations of T. christiei, except on corn in June. H. dihystera was greater in cotton and soybean plots than in corn and peanut plots from August through December.