Soil fumigation. IV.—Sorption of ethylene dibromide on soils at field capacity

1957 ◽  
Vol 8 (3) ◽  
pp. 137-142 ◽  
Author(s):  
F. Call
Weed Science ◽  
1975 ◽  
Vol 23 (3) ◽  
pp. 191-194 ◽  
Author(s):  
A. G. Ogg

Three years of field experiments showed that Canada thistle. [Cirsium arvense (L.) Scop.] could be controlled with deeply injected soil fumigants without covering the soil with a tarpaulin. The degree of control depended on the kind of fumigant, the rate of application, and the depth of injection. Weed control with fumigants usually improved as the rate of application and depth of injection increased. The most effective treatment was 1,3-dichloropropene at 560 kg/ha injected to a depth of 46 cm. Good to excellent control of Canada thistle was also obtained with 1,3-dichloropropene at 280 kg/ha injected either 23 or 46 cm and ethylene dibromide at 160 kg/ha and chloropicrin + ethylene dibromide at 20 + 55 kg/ha injected at 46 cm. Results with ethylene dibromide and chloropicrin + ethylene dibromide were more erratic than with 1,3-dichloropropene. Increasing the percentage of chloropicrin in the combination reduced the control of Canada thistle.


1953 ◽  
Vol 31 (3) ◽  
pp. 277-308 ◽  
Author(s):  
R. N. Wensley

Microbiological studies involving the use of three soil fumigants, methyl bromide, a propane–propene mixture, and ethylene dibromide, established a biological basis for the evaluation of soil fumigants as fungicides, bactericides, and actinomycides and provided quantitative and qualitative data from which the efficacy of each fumigant was rated as high, medium, low, and poor in each capacity and permitted a study of the significance of population trends. Due emphasis was placed on the two factors, concentration of the fumigant and the period of confined exposure, by determining the value of each factor required to produce, under controlled conditions of temperature and soil moisture, a 90% reduction in numbers of each microbiological group. Methyl bromide proved to be the most effective fumigant in all three capacities while ethylene dibromide formulations were least effective. The concentrations of, and exposure periods to, ethylene dibromide and the propane–propene mixture required to give satisfactory reduction of the three microbiological populations are considered high and neither fumigant is recommended as a fungicide, bactericide, or actinomycide. However, ethylene dibromide proved to be more effective than methyl bromide against root-knot nematodes and is recommended for use in this capacity. Soil fumigation effectively altered the microbiological balance in favor of fungi that were normally suppressed by a predominance of aspergilli and penicillia. Of four physiological groups of bacteria studied, nitrifiers and cellulose decomposers were most severely reduced in numbers by methyl bromide fumigation. The actinomycetes showed a greater tolerance of fumigation than either the fungi or bacteria.


1980 ◽  
Vol 60 (2) ◽  
pp. 177-184 ◽  
Author(s):  
J. L. TOWNSHEND ◽  
V. A. DIRKS ◽  
C. F. MARKS

Three southwestern Ontario soils differing in texture were studied for penetration of the nematicide ethylene dibromide. A 3 × 2 × 2 factorial experiment was used that permitted evaluation of the effects of temperature, bulk density and moisture level in all combinations on response to the fumigant. The coursest soil (Fox loamy sand) showed the most rapid penetration, with moisture level, temperature and their interactions having the greatest effect on fumigant movement. On a medium-textured soil (Vineland silt loam) the degree of penetration was dependent on moisture, temperature and bulk density, with relatively small interaction effects, suggesting that effective fumigation depends upon careful soil management and timeliness of application. On the fine-textured soil (Lincoln clay) the fumigant did not move in the soil, regardless of edaphic factors, thereby explaining the difficulty of using fumigation to control nematodes on clay. The development of factorial methods and statistical techniques to study several variables concurrently should lead to more specific and effective methods of soil fumigation.


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