Potato Late Blight and Tuber Yield: Results from 30 Years of Field Trials

The efficacy of mandipropamid (Revus 250 SC) in controlling Phytophthora infestans in potato was evaluated in field trials. The efficacies of Revus 250 SC in comparison with standard fungicides Quadris (azoxystrobin) were tested in several localities in Serbia (Kasarske Livade, Valjevska Kamenica and Opovo) in 2007 and 2008. Both of the tested fungicides exhibited high efficacy in controlling potato late blight. The differencies in the efficacy of Revus 250 SC (96.3- 99.2%) and Quadris (94.1-95.5%) were insignificant. Our experiments showed that the investigated fungicide was highly effective against P. infestans even under high disease pressure.

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Antagonistic activity of Bacillus velezensis SDTB038 against Phytophthora infestans in potato

Plant Disease ◽

10.1094/pdis-08-20-1666-re ◽

2020 ◽

Author(s):

Haohao Yan ◽

Yue Qiu ◽

Shuai Yang ◽

Yongqiang Wang ◽

Kaiyun Wang ◽

...

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Chemical Properties ◽

Good Control ◽

Potato Late Blight ◽

Field Trials ◽

Bacillus Velezensis ◽

High Concentration ◽

Control Effect ◽

Epidemic Disease

Potato late blight is a severe and highly epidemic disease caused by Phytophthora infestans that can affect all parts of the plant. This study mainly screened antagonistic strains for good control of potato late blight and identified strain SDTB038 as Bacillus velezensis according to its morphological and chemical properties and the 16S rRNA, gyrA and gyrB gene sequences. This antagonistic strain achieved good control of potato late blight in greenhouses and fields and promoted potato plant growth. Two-year field trials (2018, 2019) showed that B. velezensis SDTB038 can be used to reduce food losses caused by late blight, achieving late blight reductions of 40.79% (2018) and 37.67% (2019). In two-year field trials, the control effects of the highest concentrations of fluopimomide and B. velezensis SDTB038 were better than those of the other treatments. The control effect of 85 g ha-1 fluopimomide and B. velezensis SDTB038 and that of 170 g ha-1 fluopimomide alone showed no significant differences. These field results indicate that a low concentration of fungicide and a high concentration of SDTB038 can be effective in controlling potato late blight. Foliar detection showed that lipopeptides (LPs) have an inhibitory effect on P. infestans. The amplification of LP genes revealed surfactin (srfAB, srfAC) and fengycin (fenB) genes in SDTB038, but only surfactin production by B. velezensis SDTB038 was observed by UPLC-Q-TOF-MS analysis. Therefore, the strain B. velezensis SDTB038 can produce secondary metabolites that help potato plants resist late blight development, can effectively inhibit the infection of potato leaves by P. infestans, and has potential value for development as a biological pesticide against potato late blight.

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Resistance to Phytophthora infestans Clonal Lineage US-23 in Potato Cultivars and Its Relationship with Early Blight Resistance and Tuber Yield

Plant Disease ◽

10.1094/pdis-03-21-0594-re ◽

2021 ◽

Author(s):

Weiya Xue ◽

Kathleen G. Haynes ◽

Xinshun Qu

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Early Blight ◽

Tuber Yield ◽

Late Blight Resistance ◽

Field Trials ◽

Potato Cultivars ◽

Blight Resistance ◽

Clonal Lineage ◽

Progress Curve

Resistance to late blight, caused by Phytophthora infestans clonal lineage US-23, in 217 old and modern potato cultivars was evaluated in field trials in 2016 and 2017 in Pennsylvania. Significant differences in resistance were found among these cultivars (P < 0.0001). Significant interaction between cultivars and environments was found (P < 0.0001). The values of relative area under the disease progress curve ranged from 0 to 0.5841 in 2016 and from 0 to 0.5469 in 2017. Broad-sense heritability of late blight resistance was estimated to be 0.91 with a 95% confidence interval of 0.88 to 0.93. Cluster analysis classified the cultivars into 5 groups: resistant, moderately resistant, intermediate, moderately susceptible, and susceptible. Thirty cultivars showing resistance and 32 cultivars showing moderate resistance were identified. The 217 cultivars were also evaluated for foliar maturity, tuber yield and resistance to early blight, caused by Alternaria solani. A few cultivars with late blight resistance independent of late maturity were found. Late blight resistance and early blight resistance were positively correlated, and 17 cultivars possessed resistance to both diseases. Yield tradeoff associated with late blight resistance was not observed among the cultivars in the absence of disease pressure.

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Efficacy of fungicide combinations, phosphoric acid and plant extract from stinging nettle on potato late blight management and tuber yield

Archives of Phytopathology and Plant Protection ◽

10.1080/03235408.2012.676818 ◽

2012 ◽

Vol 45 (12) ◽

pp. 1449-1463 ◽

Cited By ~ 1

Author(s):

R. Nyankanga ◽

M. Njogu ◽

J. Muthomi ◽

M. Olanya

Keyword(s):

Phosphoric Acid ◽

Late Blight ◽

Plant Extract ◽

Tuber Yield ◽

Potato Late Blight ◽

Stinging Nettle ◽

Late Blight Management

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FUNGICIDE APPLICATION FREQUENCIES FOR POTATO LATE BLIGHT (Phytophthora infestans) MANAGEMENT IN THE DOMINICAN REPUBLIC

HortScience ◽

10.21273/hortsci.40.3.888f ◽

2005 ◽

Vol 40 (3) ◽

pp. 888f-889

Author(s):

Bielinski M. Santos ◽

James P. Gilreath ◽

Persio R. Rodriguez

Keyword(s):

Dominican Republic ◽

Late Blight ◽

Potato Late Blight ◽

Field Trials ◽

Marketable Yield ◽

Cost Component ◽

Fungicide Application ◽

The Cost ◽

Application Programs ◽

Cost Components

Field trials were conducted in Constanza, Dominican Republic to determine the most effective fungicide application programs against potato late blight, and the cost component associated to those programs. Fungicide programs were: a) chlorothalonil (1.0 kg a.i./ha) every 5, 8, 11, 14 or 17 days; b) chlorothalonil rotated with metalaxyl (1.5 kg a.i./ha) every 5, 8, 11, 14 or 17 days; c) mancozeb (1.5 kg a.i./ha) every 8 days (grower standard); and d) a nontreated control. Examined data indicated that the highest `Granola' marketable tuber weights were obtained with the rotation of metalaxyl and chlorothalonil applied every 5, 8 or 11 days (14, 9 or 6 applications/season). This same rotation every 5 or 8 days (14 or 9 applications/season) was the most effective controlling late blight. There was no correlation between disease severity and marketable yield. For the cost components, the fungicide rotation applied every 11 days reduced application costs by 29%, in comparison with applications every 8 days.

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Host Diversity Can Reduce Potato Late Blight Severity for Focal and General Patterns of Primary Inoculum

Phytopathology ◽

10.1094/phyto.2000.90.12.1307 ◽

2000 ◽

Vol 90 (12) ◽

pp. 1307-1312 ◽

Cited By ~ 42

Author(s):

K. A. Garrett ◽

C. C. Mundt

Keyword(s):

Late Blight ◽

Tuber Yield ◽

Statistical Significance ◽

Experimental System ◽

Potato Late Blight ◽

Management Tools ◽

Host Diversity ◽

Progress Curve ◽

Single Genotype ◽

Diversity Effects

The use of host diversity as a tool for management of potato late blight has not been viewed as promising in the past. But the increasing importance of late blight internationally has brought new consideration to all potential management tools. We studied the effect of host diversity on epidemics of potato late blight in Oregon, where there was little outside inoculum. The experimental system consisted of susceptible potato cv. Red LaSoda and a highly resistant breeding selection, inoculated with local isolates of US-8 Phytophthora infestans. Potatoes were grown in single-genotype plots and also in a mixture of 10 susceptible and 26 resistant potato plants. Half of the plots received inoculation evenly throughout the plot (general inoculation) and half received an equal quantity of inoculum in only one corner of the plot (focal inoculation). The area under the disease progress curve (AUDPC) was greater in single genotype stands of susceptible cv. Red LaSoda inoculated throughout the plot than with stands inoculated in one focus. The host-diversity effect on foliar late blight was significant in both years of the investigation; the AUDPC was reduced by an average of 37% in 1997 and 36% in 1998, compared with the mean disease level for the potato genotypes grown separately. Though the evidence for influence of inoculum pattern on host-diversity effects was weak (P = 0.15), in both years there was a trend toward greater host-diversity effects for general inoculation. Statistical significance of host-diversity effects on tuber yield and blight were found only in one of the two years. In that year, tuber yield from both the resistant and susceptible cultivar was increased in mixtures compared with single genotype stands and tuber blight was decreased in mixtures for susceptible cv. Red LaSoda.

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