Date of Award


Document Type


Degree Name

Master of Science

Degree Discipline



The effect of the herbicide cotoran (l,l-Dimethyl-3-(a,a,a,a-trifluoro- m-tolyl)urea on growth of A. flavus was studied in soil and liquid cultures.

The fungus was grown in modified czapek's solution containing herbicide concentrations of 1, 5, 10 and 20 ppm, plus a herbicide-free check. In another experiment, the fungus was established in flasks of sterilized sandy loam soil, and Cotoran was applied to provide concentrations of 1, 5, 10 and 20 ppm of oven-dry soil.

In liquid culture, growth of Aspergillus flavus was revealed by increased mycelial dry weight, relating to increased concentration of the herbicide. Total CO2 production by the fungus in the flasks of herbicide treated soil increased with time at concentrations of 1, 5, 10 and 20 4fg per g of soil.

Utilization of inorganic phosphorus was not significantly affected by the concentrations of the herbicide. Total acid production revealed a pattern similar to CO2 production pattern.

The study suggested that field-rate concentrations of the herbicide as indicated by the manufacturers would not stimulate the growth of Aspergillus flavus in natural field soil; whereas, higher concentrations stimulated the CO2 production in soil culture and increased dry weights of mycelium in liquid culture.

Committee Chair/Advisor

B. K. Chopra

Committee Member

T. P. Dooley

Committee Member

J.E. Berry

Committee Member

V. M. Doctor

Committee Member

J. W. Echols


Prairie View Agricultural And Mechanical College


© 2021 Prairie View A & M University

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

Date of Digitization


Contributing Institution

John B Coleman Library

City of Publication

Prairie View





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