Influence of irrigation methods and an adjuvant on the persistence of carbaryl on pakchoi.
Influence of irrigation methods and use of an adjuvant on the persistence of the carbaryl (1-naphthyl N-methylcarbamate) on pakchoi [Brassica rapa L. subsp. chinensis (Rupr.) Olsson] was studied using a commercial enzyme linked immunosorbent assay kit. After applying carbaryl at a.i. 10.6 g L(-1) with or without an adjuvant (Latron B-1956) to leaves, plants were provided water daily by either overhead or basal application. Pesticide residue on leaf tissues was examined immediately after pesticide application and on 2, 4, 6, and 8 d after pesticide application. Use of the adjuvant did not affect the initial deposit of the pesticide, however pesticide persistence was improved with the adjuvant regardless of irrigation. Overhead irrigation contributed to rapid loss of the pesticide by washing carbaryl from the leaf surface. The longest half-life of carbaryl (6.5 d) was detected on plants receiving basal irrigation plus the adjuvant while the shortest half-life (2 d) was observed when plants were treated with overhead irrigation and no adjuvant.
Marutani
Mari
M
Agricultural Experiment Station, College of Natural and Applied Sciences, University of Guam, UOG Station, Mangilao GU 96923. marutani@uog9.uog.edu
Edirveerasingam
Veronica
V
D001673:Biodegradation, Environmental; D001937:Brassica / Q000378:metabolism*; D012721:Carbaryl / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D010573:Pesticide Residues / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D018515:Plant Leaves / Q000737:chemistry; D013997:Time Factors; D014871:Water Microbiology; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*; D014881:Water Supply
D010573:Pesticide Residues; D014874:Water Pollutants, Chemical; D012721:Carbaryl