Toxicity of bunamidine

Abstract

Extract

The periodic examination of various occupational groups for serological indicators of infection, toxic agents or genetic factors associated with disease is being increasingly recommended and used by health authorities throughout the world (WHO, 1970 WHO. 1970. Multipurpose serological surveys and WHO serum reference banks. Tech. Rep. Ser. Wld Hlth Org. No. 454,  [Google Scholar]). While an immunological survey can provide information on the prevalence of infection or immune status of populations, it does not necessarily give direct evidence of the prevalence of disease. For this both epidemiological and clinical data are required.     

Aminopyralid Residue Impacts on Potatoes and Weeds

Aminopyralid is used in Alaska to control certain invasive weed species; however it appears to have an extended soil half-life in interior Alaska resulting in carry-over injury in potatoes. Field studies at three experiment stations in Delta Junction, Fairbanks, and Palmer, Alaska were established to determine the dose–response of weeds and above and below ground potato growth to soil-applied aminopyralid (0, 8, 15, 31, 62, and 123 g ae ha^?1) . Both prostrate knotweed and narrowleaf hawksbeard were susceptible to aminopyralid. At Delta Junction and Fairbanks, visual injury of potatoes greater than 25 % was observed at 15 g ae ha^?1 aminopyralid, whereas at Palmer visual injury was greater than 40 % at 8 g ae ha^?1, the lowest rate tested. Potato tuber production was reduced by aminopyralid at rates of 15 g ae ha^?1 and above at both Delta Junction and Palmer. Sub-samples of potato tubers from Delta Junction and Palmer were analyzed for aminopyralid content and grown out to determine if aminopyralid in tubers would reduce subsequent growth. The aminopyralid concentration in potato tubers increased with increasing field application rates, with 30 ppb extracted from tubers grown at the highest application rate (123 g ae ha^?1). All plants grown from daughter tubers except from control plots in Palmer exhibited injury symptoms. The number of emerged shoots, and shoot height decreased with increasing aminopyralid concentrations in the tuber, with injury rates greater than 70 % at 8 g ae ha^?1.     

Surface‐applied insecticide treatments for quarantine control of Japanese beetle,Popillia japonica Newman (Coleoptera: Scarabaeidae), larvae in field‐grown nursery plants

BACKGROUND: Japanese beetles, Popillia japonica Newman, are a quarantine challenge for nursery shipments from infested to non‐infested states. Marathon (imidacloprid) and Discus (imidacloprid + cyfluthrin) are approved preharvest nursery treatments (US Domestic Japanese Beetle Harmonization Plan; DJHP). This study evaluated approved and non‐approved (acephate, carbaryl, clothianidin, dinotefuran, halofenozide, thiamethoxam, trichlorfon) preharvest treatments, optimal rates (labeled 1×, 0.3–0.75× or 2–3×) and optimal timings (June, July, August and September) to control early‐instar (grubs) P. japonica in field nurseries. RESULTS: Most insecticides effectively reduced grub densities, except for acephate, carbaryl and trichlorfon. Clothianidin, thiamethoxam and halofenozide provided grub control equivalent to DJHP standards during most years. Across all test years and timings, percentage grub reductions were: Marathon (1×: 59.2–100; 3×: 78.9–100), Discus (1×: 60.7–100), clothianidin (1×: 96.1–100; 3×: 97.4–100), thiamethoxam (1×: 75.0–100; 3×: 80.0–100), halofenozide (1×: 70.0–100; 3×: 90.0–100) and dinotefuran (1×: 13.2–88.2; 3×: 71.1–93.4). CONCLUSIONS: July application was more consistent and effective than other timings, and higher rates (2× and 3×) did not generally improve grub control. Overall, clothianidin, thiamethoxam and halofenozide (and dinotefuran applied in August) were equivalent to current DJHP standards. These insecticides may be suitable for DJHP Category 2 states, potentially lowering grower costs. Copyright © 2009 Society of Chemical Industry     

Soil dissipation and biological activity of metolachlor and S-metolachlor in five soils

The resolved isomer of metolachlor, S-metolachlor, was registered in 1997. New formulations based primarily on the S-metolachlor isomer are more active on a gram for gram metolachlor basis than formulations based on a racemic mixture of metolachlor containing a 50:50 ratio of the R and S isomers. The labelled use rates of S-metolachlor-based products were reduced by 35% to give equivalent weed control to metolachlor. However, several companies have recently registered new metolachlor formulations with the same recommended use rates for weed control as S-metolachlor. This research was done to compare the soil behaviour and the biological activity of metolachlor and S-metolachlor in different soils under greenhouse and field conditions. Although K(d) ranged from 1.6 to 6.9 across the five soils, there were no differences in the binding of metolachlor and S-metolachlor to soil or in the rate of soil solution dissipation in a given soil. However, both greenhouse and field studies showed that S-metolachlor was 1.4-3-fold more active than metolachlor against Echinochloa crus-galli (L.) Beauv. in five different soils and that S-metolachlor was more active than metolachlor in three Colorado field locations. When the rates of metolachlor and S-metolachlor were adjusted for S isomer concentrations in the formulations, there were no differences between the formulations in field, greenhouse or bioassay studies. Thus herbicidal activity is due to the S isomers, with the R isomers being largely inactive.     

Comparison of efficacy, absorption and translocation of three glyphosate formulations on velvetleaf (Abutilon theophrasti)

Growth analysis, absorption and translocation studies were conducted to compare a 1-aminomethanamide dihydrogen tetraoxosulfate (GLY-A) formulation of glyphosate with two isopropylamine (GLY-IPA-1, GLY-IPA-2) formulations of glyphosate on velvetleaf. The two isopropylamine formulations differed by the presence of a surfactant in the formulation, GLY-IPA-1 containing surfactant whereas GLY-IPA-2 did not. Four- to six-leaf velvetleaf was treated with GLY-A and GLY-IPA-1 and GLY-IPA-2 (0, 50, 67, 89, 119, 158, 280, 420, 560 and 840 g AE ha(-1)) with and without ammonium sulfate (AMS; 20 g L(-1)). GLY-A and GLY-IPA-2 included a non-ionic surfactant (2.5 mL L(-1)) in the spray solution at all herbicide concentrations. No additional surfactant was added to GLY-IPA-1. The IC50 value for GLY-A was 88 g AE ha(-1) compared with 346 and 376 g AE ha(-1) for GLY-IPA-1 and GLY-IPA-2 respectively in the absence of AMS. When AMS (20 g L(-1)) was added to the spray solution, the estimated IC50 values were 143, 76 and 60 g AE ha(-1) for GLY-IPA-1, GLY-IPA-2 and GLY-A respectively. Absorption of 14C-glyphosate into the third leaf of five- to six-leaf velvetleaf was three- to sixfold greater 72 h after treatment (HAT) when applied as GLY-A compared with GLY-IPA-1 and GLY-IPA-2 respectively in the absence of AMS. AMS (20 g L(-1)) increased absorption of 14C-glyphosate in all glyphosate formulations two- to threefold, but differences among the formulations remained. Approximately three- and sixfold more 14C-glyphosate applied as GLY-A had translocated out of the treated leaf compared with GLY-IPA-1 and GLY-IPA-2 respectively by 72 HAT. Adding AMS (20 g L(-1)) increased translocation of 14C-glyphosate out of the treated leaf approximately 2.5-fold for all three formulations. The increased efficacy of GLY-A versus GLY-IPA-1 and GLY-IPA-2 on velvetleaf is due to the greater rate of absorption and subsequent translocation of glyphosate out of the treated leaf. AMS increased the efficacy of all three formulations by increasing absorption and translocation of glyphosate in the plant.     

Attribution of explanatory factors for change in soil organic carbon density in the native grasslands of Inner Mongolia,China

The variation in soil organic carbon density(SOCD) has been widely documented at various spatial and temporal scales. However, an accurate method for examining the attribution of explanatory factors for change in SOCD is still lacking. This study aims to attribute and quantify the key climatic factors, anthropogenic activities, and soil properties associated with SOCD change in the native grasslands of Inner Mongolia, China, by comparing data between the 1960s and the 2010s. In 2007 and 2011, we resampled 142 soil profiles which were originally sampled during 1963–1964 in the native grasslands of Inner Mongolia. SOCD was determined in A horizon(eluvial horizon) of the soil. We selected the explanatory factors based on a random forest method, and explored the relationships between SOCD change and each of the explanatory factors using a linear mixed model. Our results indicated that the change in SOCD varied from the east to the west of Inner Mongolia, and SOCD was 18% lower in the 2010s than in the 1960s. The lower SOCD in the 2010s may primarily be attributed to the increasing in mean annual water surface evaporation, which explained approximately 10% and 50% of the total variation and explainable variation in the change in SOCD, respectively. The sand content of the soil is also a significant explanatory factor for the decrease in SOCD, which explained about 4% and 21% of the total variation and explainable variation in the change in SOCD, respectively. Furthermore, the collection of quantitative information on grazing frequency and duration may also help to improve our understanding of the anthropogenic factors that govern the change in SOCD.