HPLC Determination of Linuron Residues in Asparagus Following Pre- And Early Postemergence Applications

Abstract

cBSSNe, A. J. 1990. HPLC determination of linuron residues in asparagus following pre-and postemergence applications. Can. J. Plant Sci. 70: 591-597 ' lna2-yr study, residues of the herbicide linuron were determined by HPLC in aspafagus which had been treated at two sites in British Columbia with both post-and preemergence applications at 1.1 and 2.2 kgha-l . Maximum linuron residues detected in p.""-l".g"n"e iamples were in the order of 10 pg kg -r , whereas maximum^residues inihe postemergence samples were grearer than 400 pg k8-'. Recoveries Weeds, which not only compete with the crop for light, nutrients and water but may also harbor or increase the incidence of insect and disease problems, are a major problem Can. J. Plant (Apr. 1990) for asparagus growers (Mapplebeck and Tiessen 1983). Studies with preemergence applications of linuron -N-methoxy-N-methylurea l, a herbicide used to control germinating and newly established broad-leaved weeds and grasses' showed no injury to established asparagus at application rates up to 2.0 kg ha-' (Freeman 1985. 1986: O'Sullivan and Bouw 1983 (COL2, Fig. 1), and a guard column, 23-mm x 3.9-mm i.d. (G, Fig. 1

Residue analysis of garlic (Allium sativum L.) cloves following a postemergence application of linuron

“…ha-l, and at a pressure of 275 The sample extraction and subsequent partitioning into methylene chloride were as described by Cessna (1990) (Cessna 1988(Cessna , 1990 permitted analysis of linuron using the techniques of column switching (Cessna 1988(Cessna , 1990) and backflushing the first analytical column (Cessna and Caldwell 1988 …”