title: Persistence of metalaxyl and mancozeb on potato leaves and their residues in tubers.
abstract: The persistence of fungicides on two commercial cultivars of potato was determined under field conditions at Punjab Agricultural University, Ludhiana, Punjab. Initial deposits of mancozeb on potato leaves were found to be 26.9 and 38.7 mg kg(-1), following application of ready mixture of fungicide metalaxyl 8% + mancozeb 64% (Ridomil MZ) at the rate of 1260 and 2520 g a.i. ha(-1), whereas metalaxyl residues were found to be 35.1 and 49.5 mg kg(-1), respectively. The residue level of mancozeb in potato leaves 15 days after application at single and double doze were 19.0 and 27.0 mg kg(-1) showing a loss of 29.6 and 30.3%, whereas the values for metalaxyl at single and double doze were 0.40 and 0.80 mg kg(-1) showing a loss of 98.9 and 98.4%, respectively. Residues of mancozeb and metalaxyl were not detected at 0.04 and 0.02 mg kg(-1) level in potato tubers at harvest (PHI = 53 days) at both the dosages, respectively. The persistence and dissipation of mancozeb with the application of Ridomil MZ followed similar trend as in Indofil M-45. The rate of fungicide dissipation increased with time after application in both the potato cultivars 'Kufri Chandramukhi' and 'Chipsona'. No significant difference was observed on initial deposit, persistence and dissipation of the two molecules between the two potato cultivars.
authors.affiliation: Division of Pathology, S.K. University of Agricultural Sciences and Technology of Kashmir, Shalimar, Sringar, Jammu and Kashmir 191 121, India.
authors.forename: A Alam
authors.initials: AA
authors.lastname: Wani
authors.forename: H S
authors.initials: HS
authors.lastname: Rewal
authors.forename: Sanjay
authors.initials: S
authors.lastname: Sahoo
authors.forename: Balwinder
authors.initials: B
authors.lastname: Singh
authors.forename: J Amad
authors.initials: JA
authors.lastname: Bhat
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives* / Q000032:analysis; D005659:Fungicides, Industrial / Q000032:analysis*; D006801:Humans; D008344:Maneb / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control; D018515:Plant Leaves / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis; D011198:Solanum tuberosum / Q000033:anatomy & histology* / Q000737:chemistry*; D015038:Zineb / Q000032:analysis*
chemical_list: D005659:Fungicides, Industrial; D010573:Pesticide Residues; D012989:Soil Pollutants; D008344:Maneb; C028175:metalaxyl; D000409:Alanine; C013099:mancozeb; D015038:Zineb