An appraisal of five methods for the measurement of the fungal population in soil treated with chlorothalonil

• Published in: Pest management science 2000-05, Vol.56 (5), p.431-440
• Main Authors: Vieira, Rosana F, Silva, Célia M M S, Maia, Aline H N, Fay, Elisabeth F, Coelho, Kátia C
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; chlorothalonil; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; ergosterol; Fundamental and applied biological sciences. Psychology; fungi population; fungicide; living hyphal length; microbial biomass C
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/(SICI)1526-4998(200005)56:5<431::AID-PS157>3.0.CO;2-U

An experiment was carried out in a greenhouse with the aim of determining an acceptable method to quantify the fungal population in a soil treated with the fungicide chlorothalonil. Doses of the fungicide ranging from 12 to 96 µg AI g−1 soil were applied and microbial biomass carbon (C), soil ergosterol content, living hyphal length, as well as counts of total and cellulolytic fungi colonies, were measured 1, 2, 3, 4 and 5 weeks after application. At the end of 16 weeks a new evaluation was done using the three first methods. The microbial biomass C was the least sensitive parameter and, on balance, the living hyphal length was the most sensitive parameter for demonstrating effects of chlorothalonil on the fungal population. Some problems related to the efficiency of the ergosterol content and living hyphal length measurements in the evaluation of the effect of the fungicide on the fungal microflora are discussed, as is the need to compare short‐term (0–5 weeks after treatment) with longer‐term (16 weeks) results. © 2000 Society of Chemical Industry