Translocation of Oxathiapiprolin in Bell Pepper Plants and Systemic Protection of Plants Against Phytophthora Blight

Abstract

Production of bell pepper is seriously affected by Phytophthora capsici, the causal agent of Phytophthora blight. Limited approaches are available for effective management of the disease. Oxathiapiprolin is a fungicide recently registered in the United States that suppressed P. capsici and reduced Phytophthora blight on bell pepper significantly in our previous studies. It is unknown whether oxathiapiprolin translocates in bell pepper plants systemically after application. Experiments were conducted to determine uptake of oxathiapiprolin by bell pepper plants and its systemic movement in the plant. Quantification of oxathiapiprolin in plant tissues was conducted by high-performance liquid chromatography (HPLC) that detected the compound sensitively and selectively. Percentage of recovery of oxathiapiprolin from plant tissues was calculated by comparing the quantities in plant tissues determined by HPLC with known quantities of the compound added to the plant tissues. Recovery rates of oxathiapiprolin from pepper plant tissues ranged from 87.0 to 119.3%. When oxathiapiprolin was applied to roots of bell pepper plants grown in hydroculture, the compound was detected in the root within 4 h and in the cotyledon, first true leaf, and second true leaf within 8 h. It was detectable in the top new leaf 48 h after application to the root. In greenhouse studies with bell pepper plants grown in pots, oxathiapiprolin was applied as a soil drench at 100 and 400 μg/ml. The compound was detected in the root within 3 days and in the stem and first true leaf within 6 days when applied at 100 μg/ml. It was detected in the root, stem, first true leaf, and top new leaf within 3 days when applied at 400 μg/ml. Phytophthora blight on pepper foliage was significantly reduced when oxathiapiprolin was applied as a soil drench at 100 or 400 μg/ml under greenhouse conditions. This is the first report indicating systemic movement of oxathiapiprolin in pepper plants that provides useful information for designing fungicide application programs for effective management of the disease.

Enantioselective residue analysis of oxathiapiprolin and its metabolite in tea and other crops by ultra‐high performance liquid chromatography–tandem mass spectrometry

“…1003318-67-9, C 24 H 22 F 5 N 5 O 2 S, structure in Figure 1), first discovered and developed by Dupont in July 2012 and listed in 2016, is the first piperidinyl thiazole isoxazoline fungicide exhibiting a moderate to high persistence, and it inhibits the oxysterol binding protein (OSBP) to kill fungi [7,8]. It offers growers new options for controlling black shank, late blight, and downy mildew in potatoes, grapes, citrus, tobacco, and vegetable crops [9][10][11][12][13][14][15][16]. Currently, oxathiapiprolin has been registered for use on tomatoes, cucumbers, peppers, potatoes, grapes, and other crops in China [6], and its typical metabolites are IN-E8S72, IN-WR791, and IN-SXS67 [17].…”

A new strategy for durable control of late blight in potato by a single soil application of an oxathiapiprolin mixture in early season

“…Others showed efficacy of soil drenches with oxathiapiprolin against black shank in tobacco [ 12 ], Phytophthora root rot in citrus [ 14 ] and Phytophthora blight in bell pepper [ 13 ]. No soil drench tests with the above fungicides were reported for potato.…”

“…Protection of the foliage was already detected at 1 day after root treatment, suggesting a rapid acropetal translocation of the compounds from the root. Qu et al [ 13 ] reported that when oxathiapiprolin was applied to the roots of bell pepper plants grown in hydroculture, the compound was detected in the second true leaf within 8 h and in the top new leaf 48 h after application to the root. In potted plants, translocation to the top new leaf was slower, within 3 days after application.…”

“…Soil application of 1mg active ingredient per plant provided durable protection for up to four weeks in tomato against late blight, cucumber against downy mildew and basil against downy mildew. Other researchers demonstrated efficacy of soil drench with oxathiapiprolin against Phytophthora black shank in tobacco [ 12 ] Phytophthora blight in pepper [ 13 ] and Phytophthora root rot in citrus [ 14 ].…”

Assessing the effectiveness of oxathiapiprolin towardsPhytophthora agathidicida, the causal agent of kauri dieback disease

“…It can be applied via foliar sprays, soil applications (e.g. in-furrow) or soil drenches and it is efficiently translocated throughout plant tissues in a variety of horticultural species (Cohen 2015(Cohen , 2020Qu et al 2016b), including perennial tree crops (Gray et al 2020). In addition, oxathiapiprolin has low phytotoxic effects in host tissue.…”