Bioassay for validation of metalaxyl persistence to control Phytophthora palmivora infection in durian
1
Issued Date
2023-01-01
Resource Type
ISSN
19825676
eISSN
19832052
Scopus ID
2-s2.0-85177094647
Journal Title
Tropical Plant Pathology
Rights Holder(s)
SCOPUS
Bibliographic Citation
Tropical Plant Pathology (2023)
Suggested Citation
Phetkhajone S., Siriwattanakul U., Putaporntip N., Pichakum A., Songnuan W. Bioassay for validation of metalaxyl persistence to control Phytophthora palmivora infection in durian. Tropical Plant Pathology (2023). doi:10.1007/s40858-023-00621-5 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/91167
Title
Bioassay for validation of metalaxyl persistence to control Phytophthora palmivora infection in durian
Author's Affiliation
Other Contributor(s)
Abstract
Metalaxyl is the most widely used fungicide to control Phytophthora diseases. A detached leaf bioassay was developed to quantify metalaxyl efficacy using metalaxyl-sensitive (CbP01) and metalaxyl-resistant (CbP03) isolates of Phytophthora palmivora as biological indicators. The linearity of pathogen growth on metalaxyl-treated leaves ranged from 1.6–200 ppm. This assay was applied to determine metalaxyl efficacy on durian leaf after foliar spraying and soil drenching at concentrations of 2 and 4 g/l. Metalaxyl applied as foliar spray inhibited the growth of CbP01 up to 80% for 30 days after application and up to 62–65% inhibition 60 days after application. Soil drenching strongly inhibited the growth of both CbP01 and CbP03 isolates with inhibition greater than 90% for at least 60 days after application. Although soil drenching was more effective than foliar spraying in controlling P. palmivora, soil drenching with 4 g/l metalaxyl resulted in seedling death within 15 days after application. This simple bioassay to evaluate the efficacy and persistence of metalaxyl in planta is beneficial for designing and optimizing metalaxyl application with maximum efficiency and minimum negative impacts on human health and the environment.