scholarly journals Efficacy of fungicide mixtures for the management of Phytophthora infestans (US-1) on potato

2010 ◽  
Vol 90 (1) ◽  
pp. 19-29 ◽  
Author(s):  
F.N. Muchiri ◽  
R.D. Narla ◽  
O.M. Olanya ◽  
R.O. Nyankanga ◽  
E.S. Ariga
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Tuber Yield ◽  
Severe Disease ◽  
Resistance Management ◽  
Foliar Blight ◽  
Progress Curve ◽  
Fungicide Mixtures ◽  
Spray Regimes ◽  
Disease Pressure

Fungicide application strategies (timing, frequency, rates and mixtures) are important for the control and resistance management of potato late blight caused by Phytophthora infestans. The efficacy of fungicide mixtures consisting of fenamidone + mancozeb and propamocarb HCL + mancozeb at various rates and in spray regimes containing metalaxyl and mancozeb was evaluated for late blight control (US-1) at four locations in Kenya. Propamocarb HCL + mancozeb significantly (P < 0.05) reduced foliar blight compared with mancozeb and the untreated control under moderate to severe disease pressure. Disease severity was significantly lower following application of propamocarb HCL + mancozeb at a rate of 4L ha-1 than at rates of 2L and 3L ha-1 in 1999 and 2000, but it was not significantly lower following applications at a rate of 3L ha-1 in 2000 and 2001. There were no significant differences in mean final late blight score among the three rates of 0.9, 1.0 and 1.1 kg ha-1 of fenamidone + mancozeb. All fungicide mixtures and application sequences significantly reduced the area under the disease progress curve and final late blight scores as compared with the unprotected control. Total and marketable tuber yield significantly (P < 0.05) increased in all fungicide-treated plots.

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

Plant Disease ◽  
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.

scholarly journals Field efficacy of mandipropamid for the control of potato late blight

2010 ◽  
Vol 25 (2) ◽  
pp. 157-161
Author(s):  
Emil Rekanovic ◽  
Milos Stepanovic ◽  
Milan Stevic ◽  
Ivana Potocnik ◽  
Biljana Todorovic ◽  
...  
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Potato Late Blight ◽  
Field Trials ◽  
High Efficacy ◽  
Highly Effective ◽  
Field Efficacy ◽  
Disease Pressure

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.

scholarly journals Classifying the Relative Host Reaction in Potato Cultivars and Breeding Lines to the US-8 Strain of Phytophthora infestans in Minnesota

Plant Disease ◽  
2003 ◽  
Vol 87 (8) ◽  
pp. 983-990 ◽  
Author(s):  
J. C. Jenkins ◽  
R. K. Jones
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Rank Correlation ◽  
The United States ◽  
Spearman Rank Correlation ◽  
Breeding Lines ◽  
Spearman Rank ◽  
Progress Curve ◽  
Tuber Blight ◽  
The Us

A total of 32 commercial cultivars grown in the United States and 15 potato breeding lines and non-U.S. cultivars were evaluated at Rosemount, MN for their reaction to the US-8 strain of Phytophthora infestans. Commercial red-, russet-, and white-skinned cultivars tested in the commercial cultivar trial (COMC) in 1996 and 1997 were susceptible (S) to moderately susceptible (MS) to this organism, except for Elba, which ranked as moderately resistant (MR). Yellow-fleshed cvs. Hertha, Santé, and Agria were screened in the late blight nursery (LB1) in 1997 and 1998 and classified as S to MS while Island Sunshine, Brador, and Aziza were classified as MR. The Scottish breeding line G6582-3 and U.S. breeding lines A90586-11, AWN86514-2, AWN85624-5, B0692-4, B0718-3, and B0767-2 were classified as resistant (R). Comparison among entries was based on the area under the disease progress curve (AUDPC). Spearman rank correlation for AUDPC in the 1996 and 1997 COMC trials at 14 to 18 days after inoculation (r = 0.65, P < 0.01) was greater than any other interval tested. The Spearman rank correlation for AUDPC in the 1997 and 1998 LB1 trials at 14 to 18 days after inoculation was r = 0.87, P < 0.01 and increased only slightly in successive assessment dates, suggesting that, in Minnesota, effective evaluation of the foliar infection of late blight can occur at 18 days after inoculation or later. The average tuber blight incidence for the COMC trials at harvest was 10.0% in 1996 and 9.7% in 1997. The average tuber blight incidence for the LB1 trials at harvest was 4.3% in 1997 and 14.6% in 1998. Pearson correlations between tuber blight incidence and foliar disease for the COMC trials was very low; however, for the LBl trials, it was significant in both 1997 (r = 0.53, P < 0.01) and 1998 (r = 0.53, P < 0.01). Asymptomatic tubers harvested from the COMC trials developed additional tuber blight when stored 28 days at ambient temperatures and still more when stored for another 5 months at 5°C. Surviving tubers of nine entries were planted in field trials during 1997 and 1998 to determine if plants that develop from tubers exposed to P. infestans could manifest late blight in the subsequent season. Late blight failed to develop throughout the trials in either year.

scholarly journals Protection of Susceptible Potato Cultivars Against Late Blight in Mixtures Increases with Decreasing Disease Pressure

2006 ◽  
Vol 96 (7) ◽  
pp. 777-783 ◽  
Author(s):  
F. Pilet ◽  
G. Chacón ◽  
G. A. Forbes ◽  
D. Andrivon
Keyword(s):  
Late Blight ◽  
Potato Cultivar ◽  
Progress Curve ◽  
Late Blight Disease ◽  
Natural Pressure ◽  
Blight Disease ◽  
Disease Pressure ◽  
Moderately Resistant ◽  
The Impact ◽  
Cultivar Mixtures

Cultivar mixtures can reduce potato late blight severity on susceptible cultivars. While alternating rows of susceptible and resistant cultivars would be more acceptable than random mixtures for commercial use, they increase the genotype unit area, which is an unfavorable factor for mixture efficiency, and have been minimally efficient when disease pressure is high. The effects of disease pressure on the performance of alternating rows of cultivars possessing various types and levels of resistance were investigated in 2000 and 2001 near Quito, Ecuador, where natural pressure of late blight is high. The experiments included the highly susceptible cvs. Cecilia in 2000 and LBr37 in 2001, as well as C114 (moderately resistant) and PAN (highly resistant), planted as pure stands and as the three possible two-way combinations. Different disease pressures were obtained with three spraying schedules of a contact fungicide: nontreated, one spray every second week, and one spray weekly. The area under the disease progress curve (AUDPC) on the susceptible cultivar was 0 to 20% less in mixed than in pure plots when no fungicide was applied, 13 to 26% less with a biweekly application of fungicide, and 32 to 53% less with a weekly application. These values are comparable to those obtained in previous experiments in smaller plots with designs maximizing the distance between susceptible plants. No significant differences in mixture performance were observed according to the resistant cultivar included. Effects on yield were minimal, because of the impact of factors other than late blight. Disease pressure therefore appears as a major factor conditioning the efficiency of potato cultivar mixtures against late blight.

Limiting Fungal Foliar Diseases on Carrots for Organic and Conventional Markets

2020 ◽  
Vol 21 (3) ◽  
pp. 217-223
Author(s):  
Irene Donne ◽  
Douglas S. Higgins ◽  
Elizabeth Brisco-McCann ◽  
Mary K. Hausbeck
Keyword(s):  
Production Systems ◽  
Management Strategies ◽  
Field Trials ◽  
Copper Hydroxide ◽  
Foliar Diseases ◽  
Foliar Blight ◽  
Progress Curve ◽  
Conventional Production ◽  
Alternaria Dauci ◽  
Disease Pressure

Michigan ranks fourth in carrot production for the combined fresh and processing markets. Fungal foliar diseases caused by Alternaria dauci and Cercospora carotae occur annually in the state, causing blighted and weakened leaves and petioles. Our objective was to update current disease management strategies for both organic and conventional production by testing Organic Materials Review Institute (OMRI)–approved and conventional fungicides against C. carotae and A. dauci. Field trials conducted in 2015 and 2016 found that the copper-based fungicides (copper hydroxide and copper hydroxide/copper oxychloride) were the only OMRI-approved products that, as indicated by relative area under the disease progress curve (rAUDPC) data, consistently limited foliar blight. In field trials of conventional fungicides, all treatments limited symptomatic foliar area and protected petiole health compared with the control in both years with one exception: propiconazole was similar to the control in 2016 for petiole health and in 2015 for rAUDPC values. During 2016 when disease pressure was high, pyraclostrobin/fluxapyroxad outperformed iprodione, pyraclostrobin, azoxystrobin/propiconazole, and cyprodinil/fludioxonil for the control of foliar blight. Yields differed significantly among conventional treatments only in 2016. In plots sprayed with pyraclostrobin/boscalid, pyraclostrobin/fluxapyroxad, chlorothalonil, and boscalid had higher yields than penthiopyrad, iprodione, and propiconazole. These results can contribute to management strategies for C. carotae and A. dauci in organic or conventional production systems.

scholarly journals Evaluation of potato (Solanum tuberosum L.) genotypes for resistance to late blight at Sinana Southeastern Ethiopia

2016 ◽  
Vol 6 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Getachew Asefa ◽  
Wassu Mohammed ◽  
Tesfaye Abebe
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Agricultural Research ◽  
Solanum Tuberosum L ◽  
Block Design ◽  
Severity Index ◽  
High Yield ◽  
Mean Values ◽  
Progress Curve ◽  
Moderately Resistant

Late blight caused by Phytophthora infestans (Mont.) de Bary, is one of the most significant constraints to potato production in Bale high lands and other regions of Ethiopia. Hence, this requires to develop high yielding and late blight resistant varieties. Therefore, this study was conducted to determine host resistance of potato against Phytophthora infestans in order to develop late blight resistant/tolerant genotypes. The experiment was laid out in randomized complete block design with three replications at Sinana Agricultural Research Center during 2014 main cropping season. The genotypes showed highly significant (P<0.01) differences for all the characters studied. Genotypes exhibited wide ranges of mean values for all characters. The highest total tuber yield (46.1 t ha-1) was obtained from the advanced clone, CIP-392640.524 followed by Belete (41 t ha-1). Late blight appeared early on farmer's cultivar Kellacho (48 days after planting) and late on advanced clones CIP- 399062.102(74 days after planting). Percent severity index (PSI) and area under disease progress curve (AUDPC) ranged from 33.91 to 91.67% and 105 to 2370, respectively. Eleven newly introduced clones and the released variety "Belete" recorded PSI 33 to 39.7% and AUDPC 105 to 264.1. Hence, these genotypes can be categorized as moderately resistant. The study revealed the presence of considerable variability in tested genotypes for economically important traits and the higher chance of selecting genotypes with high yield and moderately resistant to late blight. However, it appears that further evaluation of genotypes across seasons and locations to identify genotypes that could be released as varieties seem to be quite pertinent.Int. J. Agril. Res. Innov. & Tech. 6 (1): 21-25, June, 2016

scholarly journals Evaluasi Resistensi dan Daya Hasil Enam Klon Harapan Kentang Transgenik Terhadap Serangan Penyakit Hawar Daun (Evaluation of Resistance to Late Blight and Tuber Yield of Six Potential Potato Transgenic Clones)

2019 ◽  
Vol 28 (1) ◽  
pp. 41
Author(s):  
NFN Kusmana ◽  
Alberta Dinar Ambarwati
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Tuber Yield ◽  
Potato Crop ◽  
Transgenic Potato ◽  
Yield Component ◽  
Experimental Unit ◽  
Plant Vigor ◽  
Main Plot ◽  
Rb Gene

<p>Penyakit hawar daun (Phytophthora infestans) merupakan salah satu penyakit utama pada tanaman kentang. Kerusakan yang berat akibat penyakit hawar daun dapat menyebabkan kehilangan hasil panen sampai 80%. Gen pembawa ketahanan terhadap penyakit hawar daun dikenal dengan nama gen RB dan telah berhasil dimasukkan ke dalam genom kentang dan menghasilkan kentang transgenik. Tujuan penelitian untuk menguji ketahanan enam klon kentang transgenik terhadap serangan penyakit hawar daun (P. infestans) dan daya hasil. Penelitian dilakukan di Lapangan Uji Terbatas Desa Citere, Kecamatan Pangalengan, Kabupaten Bandung, 1.400 m di atas permukaan laut. Rancangan percobaan menggunakan rancangan petak terpisah, dengan petak utama perlakuan tidak disemprot fungisida dan disemprot fungisida dua kali seminggu dan anak petak 10 genotipe kentang yang terdiri atas enam hibrida kentang transgenik, satu genotipe kentang transgenik Katahdin SP951 sebagai pembanding resisten dan tiga varietas pembanding rentan kentang nontransgenik Granola, Atlantic, dan Katahdin. Jumlah ulangan tiga kali dengan populasi tanaman terdiri atas 50 tanaman/plot. Pengamatan dilakukan terhadap vigor tanaman, insiden serangan hawar daun, dan komponen hasil. Hasil pengamatan menunjukkan bahwa untuk vigor tanaman tidak terjadi interaksi serta antarperlakuan tidak berbeda nyata. Genotipe yang resisten terhadap hawar daun adalah klon 20, 27, 65, dan 66 setara dengan kontrol positif Katahdin SP951 dan nyata lebih resisten dari varietas pembanding Granola, Atlantic, dan Katahdin. Klon yang resisten terhadap hawar daun menampilkan hasil yang tinggi pada plot tidak disemprot fungisida, sementara pada plot disemprot fungisida 20 kali semua genotipe menampilkan hasil optimalnya. Tingkat kehilangan hasil mencapai 18,8–84,4%. Genotipe dengan intensitas serangan hawar daun tinggi memiliki tingkat kehilangan hasil yang juga tinggi. Klon 20 dan 27 menampilkan daya hasil yang relatif tinggi dengan penundaan penggunaan fungisida 7 minggu setelah tanam.</p><p><strong>Keywords</strong></p><p>Genotipe; <em>P. infestans; Solanum tuberosum</em> L</p><p><strong>Abstract</strong></p><p>Late blight (Phytophthora infestans) is one of main potato diseases. Due to severe damage to late blight potato, crop will be cause lost of harvest up to 80%. Gene carriers of resistance to late blight known as the RB gene and have been incorporate into the genom of potato and produce transgenic potato. The objective of the research was to test six advanced transgenic potato clones for resistance to late blight (Phytophthora infestans). The research was conducted at Confined Field Trial at Citere Village, Pangalengan District Bandung (1,400 m above sea level). The experimental design was split plot. The main plot was spray with fungicides twice/week and was replicated three times. Subplot were 10 potato genotypes, consists of six transgenic potato hybrids, transgenic Katahdin SP951 as resistant check and three varieties of nontransgenic as susceptible check, i.e. Granola, Atlantic, and Katahdin.  An experimental unit consists of 50 plants/plot, every treatment with three replicates. Plant observed were plant vigor, intensity of late blight damage, tuber yield component, and lost of yield. The result showed that there were no interaction of plant vigor and also all the treatmens were not significantly different. Transgenic potato clones of 20, 27, 65, 66, and Katahdin SP951 were resistant to late blight compare to check varieties of Granola, Atlantic, and Katahdin. The highest yielding at none spraying of fungicides were obtained from the resistance clones. Whereas,  on the 20 sprayed fungicides all of  the clones were high yielding. Tuber yield lossed ranged from 18,8–84,4%, the susceptible genotypes were also showed high losses. Clones 20 and 27 showed reletive high yielding and can be delayed application fungicides for period of 7 weeks after planting. </p>

scholarly journals RESISTANCE EVALUATION ON POPULATIONS OF CROSSES BETWEEN TRANSGENIC POTATO KATAHDIN RB AND NON-TRANSGENIC ATLANTIC AND GRANOLA TO LATE BLIGHT (Phytophthora infestans) IN CONFINED FIELD TRIAL

2011 ◽  
Vol 12 (1) ◽  
pp. 33 ◽  
Author(s):  
Alberta Dinar Ambarwati ◽  
Muhammad Herman ◽  
Agus Purwito ◽  
Sientje Mandang Sumaraw ◽  
Hajrial Aswidinnoor
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Resistance Gene ◽  
Field Trial ◽  
Transgenic Potato ◽  
Solanum Bulbocastanum ◽  
Resistance Level ◽  
Progress Curve ◽  
Resistance Score ◽  
Confined Field Trial

Late blight resistance gene (RB gene) isolated from Solanum bulbocastanum, is a broad resistance gene against all races of Phytophthora infestans. The gene was transformed into Katah-din event SP904 and SP951 using Agrobacterium tumefaciens and these transgenic plants have been crossed with susceptible potato cultivars Atlantic and Granola. Populations of the crosses have been molecularly characterized for the integration of the RB transgene. The study aimed to evaluate the resistance of the populations of crosses between transgenic Katahdin RB  and susceptible non-transgenic parents (Atlantic and Granola) to late blight in a confined field trial at Pasir Sarongge, Cianjur, West Java. A total of 84 clones originated from four popula-tions were evaluated for resistance to late blight. These included 22 clones of Atlantic x transgenic Katahdin SP904, 16 clones of Atlantic x transgenic Katahdin SP951, 19 clones of Granola x transgenic Katahdin SP904, and 27 clones of Granola x transgenic Katahdin SP951. Observations of the late blight infection were conducted when late blight symptoms were detected, i.e. at 56, 60, 63, 70, and 77 days after planting (DAP). The result showed there were high variations in the resistance level of all the 84 clones tested. Clones of crosses between susceptible parents (Atlantic or Granola) and resistant parents (transgenic Katahdin SP904 or Katahdin SP951) showed a similar pattern based on the area under disease progress curve (AUDPC) value, i.e. 377.2 greater than the AUDPC of the resistant parents (180.1), but smaller than that of the susceptible parents (670.7). Observation at 77 DAP resulted four resistant potato clones having resistance score of 7.0-7.6, higher than the transgenic parents Katahdin SP904 (4.6) and Katahdin SP951 (6.8), i.e. clone B8 (Atlantic x transgenic Katahdin SP951) with resistance score of 7.6 and clones B26 (Atlantic x transgenic Katahdin SP951), C183 (Granola x transgenic Katahdin SP904), and D89 (Granola x transgenic Katahdin SP951) with resistance score of 7. These four transgenic potato resistant clones need to be further developed as promising potato clones to late blight.<br /><br />

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