摘要:

Soil organic matter is frequently associated with reduced herbicide mobility and phytotoxicity. The objective of this study was to determine the effect of lagoon effluent application on runoff and leaching losses of atrazine. Tilted beds, packed with Tifton soil and equipped with runoff and leachate collection funnels, were utilized. Lagoon effluent was applied at three rates, followed by atrazine and bromide application. Simulated rainfall (5 cm h‐1) was applied for two hours, and runoff and leachate were collected. Increasing the rate of effluent application increased runoff flow rate and decreased leaching flow rate. The percentage of atrazine lost in runoff increased with effluent application rate, but the percentage lost to leaching decreased. Therefore, the total atrazine lost was not affected by effluent application rate. However, lagoon effluent application to land can increase the potential for atrazine runoff. Care must be taken to avoid atrazine contamination of surface waters from effluent amended land.

ISSN:0360-1234    

DOI:10.1080/03601239309372812

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This study determined the kinetics of decomposition of atrazine in well water and deionized water refrigerated (4°C) and at slightly above room temperature (30°C.) When water samples containing normal groundwater pHs and dissolved organic carbon levels were brought to a known concentration of atrazine (400 nmol L‐1) and stored 19 weeks, no significant loss in atrazine concentration occurred. First‐order rate constants ranged from ‐2.4 × 10‐3to ‐3.7 × 10‐3weeks‐1. These results indicate that those quality assurance/quality control protocols that require holding times of less than 48 hours in the laboratory prior to extraction should be updated to allow flexibility dependent on the pesticide provided that the appropriate controls and documentation are in place.

ISSN:0360-1234    

DOI:10.1080/03601239309372813

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

An aqueous solution of acephate, an organophosphate systemic insecticide, was painted onto the injured bark of clipped branch tips of white spruce containing fresh cones, at dosage rates of 5 and 10 mg in 0.2 mL. Twelve days later the cones were harvested for residue analysis. Acephate was taken up by the cones from the treated region, and was partly converted into its major metabolite, methamidophos. Contaminated cones were then placed in moist sandy loam and clay loam soils, and also in pond and river water. All samples were incubated for 48 h with gentle agitation. Residues of acephate and methamidophos were measured in soil and water at different intervals up to 45 d, to study persistence.

ISSN:0360-1234    

DOI:10.1080/03601239309372814

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Tests were conducted to determine the effects of fungicides, captafol and chlorothalonil, on microbial and enzymatic activities in sandy loam. The results indicated that when captafol or chlorothalonil was added to the sandy loam, bacterial and fungicidal populations initially decreased with the treatments but recovered rapidly to levels similar to those in the controls. No inhibition on oxidation of soil ammonia or organic sulfur was observed. The fungicide treatments significantly increased oxygen consumption from the decomposition of organic matter indigenous to the soil. Both fungicides suppressed invertase and amylase for 1 day. However, the inhibitory effect disappeared after 2 days. Captafol depressed dehydrogenase for 4 days and recovered to equal to that of control after 7 days. No inhibitory effect on urease and phosphatase was shown with the fungicidal treatments. Although some stimulatory influences of fungicides on microbial and enzymatic activities were found in the soil, in no instance were the effects dramatic or sufficient enough to be considered important to soil fertility.

ISSN:0360-1234    

DOI:10.1080/03601239309372815

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The acute toxicity of two organophosphorus (OP) pesticides, diazinon and malathion toCyprinus carpioandBarilius vagrawas determined. Mortalities and LC50–96 hr values for 8.vagraandC. carpiowere variable. Both juvenile common carp andB. vagrawere extremely sensitive to diazinon. AdultB. vagrawere more sensitive to malathion than were juvenile common carp.

ISSN:0360-1234    

DOI:10.1080/03601239309372816

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Susceptibility of third instar gypsy moth(Lymantria disparL.) toBacillus thuringiensisin the formulated product Foray 48B (Novo Nordisk Bioindustrials, Inc., Danbury, CT) was evaluated. The bioassay technique involved feeding larvae droplets of the formulation sprayed on leaf discs. The amount of leaf material consumed, time to mortality, and weight increase were measured. The LD95was 21.1 International Units (IU)/larvae. After seven days, surviving larvae in the B.thuringiensistreatments weighed significantly less than the untreated larvae (p<0.05). The mean treatment time to mortality ranged between 37.7–45.0 h. No significant difference was found in the percentage of leaf material consumed when larvae were exposed to 1.5 IU, or 11.8 IU per leaf disc.

ISSN:0360-1234    

DOI:10.1080/03601239309372817

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Effects of ionizing radiation on the emergence of locomotor skill, and physical development were studied in laboratory rats (Fisher F‐344 inbred strain). Rats were treated with 3 different doses of radiation (150 rad, 15 rad, and 6.8 rad) delivered on the 20th day of prenatal life. Results indicated that relatively moderate (15 rad) to high (150 rad) doses of radiation had effects on certain locomotion and physical development parameters. Exposure to 150 rad delayed pivoting, cliff‐avoidance, upper jaw tooth eruption, and decreased body weights. Other parameters, such as negative geotaxis, eye opening, and lower jaw tooth eruption were marginally delayed in the 150 rad treated animals. Exposure to 15 rad delayed pivoting and cliff‐avoidance.

ISSN:0360-1234    

DOI:10.1080/03601239309372818

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor