Effects of cuticular waxes on permeation of fungicides azoxystrobin and chlorothalonil into apples

Abstract

Time-dependent permeation characteristics of two fungicides azoxystrobin and chlorothalonil into apples were investigated in the presence and absence of the cuticular waxes. Either apple samples which were subjected to waxremoving treatment or not (raw) were individually submerged in each dilution solution of the tested fungicides for a short time, and some of each submerged sample were then washed in running tap water. All apple samples were incubated under controlled conditions and collected sequentially after 1, 24, and 48 h. The collected apple samples were divided into four tissue parts before fungicide residue analysis: peel, pulp-1, pulp-2, and pulp-3. Most residues of azoxystrobin (70.7-86.4%) in apples were present in the peel, and the residual extents in the pulps increased by removal of cuticular waxes. By washing treatment, 52.3-69.2% of azoxystrobin residues in raw apples were removed. Meanwhile, all chlorothalonil residues were determined in the peel of apples, and their concentrations slightly increased by wax removal. However, significant chlorothalonil residues (84.5-91.1%) were removed by washing the apple surface. Results in this study may be extensively utilized as basic data to understand characteristics of cuticular permeation and translocation of fungicides applied on fruit crops.

Determination of Modified QuEChERS Method for Chlorothalonil Analysis in Agricultural Products Using Gas Chromatography–Mass Spectrometry (GC-MS/MS)

“…Moreover, chlorothalonil is known to be used in post-harvest treatment as a chemical control agent [29]; thus, it is expected that it can be used to yield high detection rate in apples. However, the results of one study indicated that residual chlorothalonil was significantly removed from the apple surface after washing [30]. Watermelons and cucumbers are classified as cucurbits, and chlorothalonil is used to protect against gummy stem blight, powdery mildew, and anthracnose infections [31].…”

“…These five products were analyzed to confirm the presence of non-detected target pesticides and used for method validation. Agricultural products for the monitoring of chlorothalonil were collected from Seoul (47), Busan (43), Incheon (35), Daegu (31), Daejeon (24), Suwon (20), Ulsan (20), Gwangju (20), Cheongju (16), Changwon (18), Wonju (14), Jeju (12), Jeonju (10), and an online market (30) in Republic of Korea. A total of 15 commodities were selected for monitoring, and 340 samples were collected from local markets: vegetables (154), fruits (91), potatoes (47), cereals (34), and legumes (14).…”

Interaction between Six Waxy Components in Summer Black Grapes (Vitis vinifera) and Mancozeb and Its Effect on the Residue of Mancozeb

“…It also reduces the infestation of some pests and diseases [7] and enhances the mechanical strength of grape peel [8]. However, some studies have proposed that the waxy layer structure on the surface of fruits may provide a way for hydrophobic pesticides to penetrate plant tissues [9,10].…”

“…However, some experiments yield the opposite results. For example, the concentration of azoxystrobin in washed apples was lower in samples with wax removed than in samples without wax extracted from the cuticle [9]. Pesticide residues on citrus and waxed apples are primarily concentrated in the epidermal wax [28,29], which is thought to be because those pesticides may dry on the surface or bind to the wax outside the peel and then adhere to the peel, thus remaining nonremovable in the wash treatment [30].…”

Dynamic changes in wax and cutin compounds and the relationship with water loss in 'Red Fuji' and 'Golden Delicious' apples during shelf life

“…The cuticle characteristics of apples can be affected by various factors, such as the plant cultivar, treatment with 1‐methylcyclopropene (1‐MCP) and storage conditioning, (Matas et al ., 2011; Hwang et al ., 2019). However, most of these studies focused on a specific duration of storage or a single developmental stage (Lara et al ., 2019), and little is known about changes in combined wax and cutin compounds in postharvest apple fruit.…”