scholarly journals Baseline Sensitivity and Control Efficacy of Pyraclostrobin Against Botryosphaeria dothidea Isolates in China

Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1458-1463 ◽  
Author(s):  
Kun Fan ◽  
Jie Wang ◽  
Li Fu ◽  
Guo Fu Zhang ◽  
Hai Bin Wu ◽  
...  
Keyword(s):  
Control Measure ◽  
Mean Value ◽  
Cross Resistance ◽  
Botryosphaeria Dothidea ◽  
Baseline Sensitivity ◽  
Control Efficacy ◽  
Quinone Outside Inhibitor ◽  
Ring Rot ◽  
Rot Disease ◽  
And Control

Botryosphaeria dothidea is an important fungal pathogen that causes apple ring rot, which can significantly reduce apple yield. Fungicide applications are the main control measure of apple ring rot worldwide. Pyraclostrobin is a quinone outside inhibitor (QoI) fungicide that has yet to be registered for control of B. dothidea in China. Baseline sensitivity of B. dothidea to pyraclostrobin (EC50 of mycelial growth inhibition) was assessed for 97 isolates collected in Shandong Province. The EC50 values ranged from 0.7010 to 7.1378 μg/ml with the mean value of 3.0870 μg/ml and displayed a unimodal frequency distribution. After cultured on fungicide-free PDA medium or on apples for multiple generations, the B. dothidea–resistant isolates (RST) remained resistant to pyraclostrobin, but exhibited similar virulence as the susceptible isolates (ST). Cross-resistance investigation revealed that pyraclostrobin was not cross-resistant to tebuconazole, flusilazole, carbendazim, and iprodione. Field evolution showed that pyraclostrobin at 200 and 250 g a.i./ha provided greater than 80% control efficacy against apple ring rot disease when applied as a therapeutic or preventive fungicide. The efficacy was similar to fungicides that have been registered for apple.

scholarly journals Baseline sensitivity and resistance risk assessment of Valsa mali to pyraclostrobin

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Hao Feng ◽  
Shuai Wang ◽  
Zhaoyang Liu ◽  
Jianqiang Miao ◽  
Mingxia Zhou ◽  
...  
Keyword(s):  
Geographic Location ◽  
Hyphal Growth ◽  
Dry Weight ◽  
Mean Value ◽  
Cross Resistance ◽  
Baseline Sensitivity ◽  
Resistance Risk ◽  
Quinone Outside Inhibitor ◽  
Significant Difference ◽  
Valsa Mali

Abstract Pyraclostrobin, a quinone outside inhibitor (QoI) fungicide, has been registered to control apple tree Valsa canker (AVC) caused by Valsa mali in China. However, there is no data available regarding the resistance risk of V. mali to pyraclostrobin. In this study, the sensitivities of 120 V. mali isolates to pyraclostrobin were detected. The isolates were collected from apple orchards with no application of pyraclostrob at six provinces in China during 2013–2015, and showed similar sensitivity to pyraclostrobin. The EC50 values of these 120 V. mali isolates to pyraclostrobin ranged from 0.0014 to 0.0240 μg/mL, indicating an excellent inhibitory efficacy of pyraclostrobin to the pathogen. The EC50 values were distributed as a unimodal curve with a mean value of 0.0091 μg/mL, and the mean EC50 displayed correlation with geographic location. Meanwhile, three pyraclostrobin-resistant mutants (PR mutants) of V. mali were obtained using fungicide adaption method, with a resistance factor (RF) of 41.0, 56.8 and 22.0, respectively. The mutants showed a stable resistance to pyraclostrobin after 10 transfers on pyraclostrobin-free medium. Comparing with the corresponding parental isolates, the hyphal growth, mycelial dry weight and pathogenicity of PR mutants were significantly reduced, but the number of propagules showed no significant difference. More importantly, no cross-resistance of PR mutants to pyraclostrobin, tebuconazole, difenoconazole, imazalil and thiophanate-methyl was detected. In conclusion, V. mali showed a moderate risk to pyraclostrobin, and pyraclostrobin could be used as an alternative fungicide to control AVC in the field in China.

scholarly journals Evaluating the Sensitivity and Efficacy of Fungicides with Different Modes of Action Against Botryosphaeria dothidea

Plant Disease ◽  
2018 ◽  
Vol 102 (9) ◽  
pp. 1785-1793 ◽  
Author(s):  
Yingying Song ◽  
Lili Li ◽  
Chao Li ◽  
Zengbin Lu ◽  
Xingyuan Men ◽  
...  
Keyword(s):  
Field Trials ◽  
Apple Fruit ◽  
Effective Concentration ◽  
Botryosphaeria Dothidea ◽  
Control Efficacy ◽  
Frequency Distributions ◽  
Considerable Potential ◽  
Ring Rot ◽  
Fungal Plant Pathogen ◽  
The Mean

Botryosphaeria dothidea, the causal agent of apple ring rot, is an important fungal plant pathogen that can cause serious reductions in crop yield, and fungicides still play a crucial role in management. In the present study, the sensitivity of B. dothidea to fludioxonil, fluazinam, and pyrisoxazole was assessed in 162 isolates. Moreover, the protective and curative activity of the three fungicides on detached apple fruit as well as the control efficacy in the field were determined. The results showed that the mean 50% effective concentration (EC50) values (± standard deviation) were 0.01 ± 0.008, 0.04 ± 0.03, and 0.02 ± 0.01 μg ml−1, with individual EC50 values of 0.002 to 0.05, 0.003 to 0.19, and 0.005 to 0.26 μg ml−1 for fludioxonil, fluazinam, and pyrisoxazole, respectively. In addition, the frequency distributions of EC50 values were both unimodal curves. However, significant correlations (P < 0.05) were found between fludioxonil and iprodione, between fluazinam and iprodione, as well as between pyrisoxazole and difenoconazole. In field trials conducted during 2016 and 2017, the control efficacy ranged from 75.91 to 87.41% when fludioxonil was applied at 100 to 150 mg active ingredient (a.i.) kg−1, 81.90 to 85.13% when fluazinam was applied at 400 mg a.i. kg−1, and 77.43 to 80.97% when pyrisoxazole was applied at 400 mg a.i. kg−1. The control efficacy of the fungicides in storage was higher than 60%, with the exception of fluazinam. These results demonstrated that fludioxonil, fluazinam, and pyrisoxazole have considerable potential to control apple ring rot.

Baseline sensitivity and control efficacy of propiconazole against Sclerotinia sclerotiorum

2018 ◽  
Vol 114 ◽  
pp. 208-214 ◽  
Author(s):  
Jun Zhang ◽  
Simin Hu ◽  
Qianru Xu ◽  
Hong You ◽  
Fuxing Zhu
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Baseline Sensitivity ◽  
Control Efficacy ◽  
And Control

Baseline sensitivity and control efficacy of DMI fungicide epoxiconazole against Sclerotinia sclerotiorum

2014 ◽  
Vol 141 (2) ◽  
pp. 237-246 ◽  
Author(s):  
Jin-Li Li ◽  
Xiang-Yang Liu ◽  
Ya-Li Di ◽  
Hong-Jie Liang ◽  
Fu-Xing Zhu
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Baseline Sensitivity ◽  
Control Efficacy ◽  
And Control

Baseline sensitivity and control efficacy of epoxiconazole against Fusarium graminearum in Henan Province, China

2020 ◽  
Vol 157 (4) ◽  
pp. 825-833
Author(s):  
Shengming Liu ◽  
Liuyuan Fu ◽  
Jinpeng Chen ◽  
Shuan Wang ◽  
Jinliang Liu ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Henan Province ◽  
Baseline Sensitivity ◽  
Control Efficacy ◽  
And Control

Baseline sensitivity and control efficacy of fluazinam against Clarireedia homoeocarpa

2020 ◽  
Vol 137 ◽  
pp. 105290
Author(s):  
Jian Hu ◽  
Jiaxuan Wu ◽  
Murong Gu ◽  
Jiamei Geng ◽  
Cheng Guo ◽  
...  
Keyword(s):  
Baseline Sensitivity ◽  
Control Efficacy ◽  
And Control

scholarly journals Baseline Sensitivity of Botrytis cinerea to Pyraclostrobin and Boscalid and Control of Anilinopyrimidine- and Benzimidazole-Resistant Strains by These Fungicides

Plant Disease ◽  
2008 ◽  
Vol 92 (10) ◽  
pp. 1427-1431 ◽  
Author(s):  
C. K. Myresiotis ◽  
G. A. Bardas ◽  
G. S. Karaoglanidis
Keyword(s):  
Electron Transport ◽  
Botrytis Cinerea ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Cross Resistance ◽  
Vegetable Crops ◽  
Baseline Sensitivity ◽  
Transport Chain ◽  
Resistant Strains ◽  
And Control

Fifty-five isolates of Botrytis cinerea collected from vegetable crops were used to determine the pathogen's baseline sensitivity to two new fungicides: boscalid, which inhibits the enzyme succinate dehydrogenase in the electron transport chain, and pyraclostrobin, which blocks electron transport between cytochrome b and cytochrome c1. Measurement of sensitivity to boscalid was based on both inhibition of mycelial growth and spore germination, while measurement of sensitivity to pyraclostrobin was based only on inhibition of spore germination. For both fungicides, the sensitivity distribution was a unimodal curve, with a mean EC50 value (effective concentration that reduces mycelial growth or spore germination by 50%) of 0.033 μg ml-1 for pyraclostrobin and 2.09 and 2.14 μg ml-1 for boscalid based on the inhibition of mycelial growth and spore germination, respectively. No cross-sensitivity relationship was observed between the two fungicides (r = 0.09). In addition, no cross-resistance relationship was observed between these two fungicides with other botryticides: cyprodinil, pyrimethanil, fenhexamid, fludioxonil, and iprodione. Moreover, the control efficacy of the two fungicides was tested against two anilinopyrimidine-resistant and two benzimidazole-resistant isolates, and two of wild-type sensitivity. Both pyraclostrobin and boscalid provided satisfactory control of all six isolates that was independent of the isolate sensitivity to benzimidazoles and anilinopyrimidines. In contrast, carbendazim failed to control sufficiently the benzimidazole-resistant isolates, while cyprodinil failed to provide satisfactory control of the anilinopyrimidine-resistant isolates.

Sign in / Sign up

Export Citation Format

Share Document