Toxicity of mancozeb, chlorothalonil, captan, fluopyram, boscalid, and difenoconazole toDidymella applanataisolates from Serbia

Abstract

Field isolates of Didymella applanata, the causal agent of spur blight of raspberry, were evaluated in vitro for their sensitivity to mancozeb, chlorothalonil, captan, fluopyram, boscalid and difenoconazole. A total of 10 isolates, collected during 2013 at five localities in the major raspberry growing region in Serbia, and characterized as copper hydroxide, dithianon, and tebuconazole (sensitive), pyraclostrobin (sensitive or highly resistant) and fluazinam (sensitive or moderately resistant), were used in this study. The EC50 values for the isolates ranged from 1.33 to 2.88 mg L(-1) for mancozeb, from 3.18 to 6.65 mg L(-1) for chlorothalonil, from 15.75 to 24.69 mg L(-1) for captan and from 1.80 to 8.20 mg L(-1) for fluopyram. The narrowest range of EC50 values was recorded for difenoconazole (0.23-0.49 mg L(-1)), whereas the widest range was obtained for boscalid (4.49-49.25 mg L(-1)). The calculated resistance factors showed that all D. applanata isolates were sensitive to mancozeb, chlorothalonil, captan, and difenoconazole. Four isolates were moderately resistant to boscalid, while three of them were also moderately resistant to fluopyram. This finding of moderately resistant isolates to these SDHI fungicides indicates a possible cross-resistance which should be clarified in further investigations.

Constraining Evolution of Alternaria alternata Resistance to a Demethylation Inhibitor (DMI) Fungicide Difenoconazole

“…Difenoconazole has been used to control many cereal, vegetable and fruit diseases including potato early blight in China since 1998 and ∼10% of its global production is sold in Chinese markets recent years 1 ,2 (Zheng et al, 2013). However, this observation is consistent with previous results showing that difenoconazole is still effective in controlling many plant pathogens such as A. solani , Rhizoctonia cerealis , Colletotrichum capsici , Didymella applanata , and Ceratocystis fimbriata (Reuveni and Sheglov, 2002; Gopinath et al, 2006; Mirkovic et al, 2015; Wang et al, 2016; Scruggs et al, 2017) and suggests that there is a low risk of developing difenoconazole resistance in many plant pathogens (Hamada et al, 2011; Fonseka and Gudmestad, 2016).…”

Effect of Mancozeb on Mustard (Brassica juncea L.): An In-vitro study

“…It was also reported that higher dose of Mancozeb have negative effect on plant growth and activity of mycorrhizal symbiosis (Saleh 2006, Chaurasia 2014. According to Kackar et al (1997) and Mirkovic et al (2015) chronic oral feeding of Mancozeb has produced dose dependent toxicity and death of animal by structural and functional changes like significant increase in thyroid, body weight ratio and histopathological changes. Easton et al (2001) reported that by the effect of Mancozeb fungicide novel proteins being induced and stress were increased.…”

Establishment of an EC50 database of pesticides using a Vibrio fischeri bioluminescence method

“…Pesticide toxicity can be determined using several methods based on various types of microorganisms, such as Didymella applanata , Vibrio fischeri , Selenastrum apricornotum and Daphnia magna. For instance, the Daphnia magna motility assay has been used to determine pesticide toxicity . In this study a toxicity test using the bioluminescent bacteria Vibrio fischeri was chosen because it is widely used, quick, and easy to perform …”