scholarly journals MANAGEMENT OF POTATO LATE BLIGHT THROUGH HOST PLANT RESISTANCE AND FUNGICIDE USE IN SOUTH OMO ZONE, SNNPR, ETHIOPIA

2017 ◽  
Vol 5 (5) ◽  
pp. 342-348
Author(s):  
Misgana Mitiku ◽  
Yesuf Eshete

The study was carried out in April 2015 at South Ari district, Senmamer kebele of South Omo Zone Southern Nation Nationality People Regional State to test and demonstrate the effects of integrating host resistance and fungicide application for management of potato late blight disease. In this experiment one relatively late blight resistance improved Irish potato variety (Belete) was collected from Holleta Seed producer Association and susceptible local control potato varieties were used. RCBD with four replications (farmers as replication) were used. A recommended rate of CurzateR R WP fungicide was applied while susceptible local variety developed the first blight symptom. GLM procedures were followed to analyze yield, disease incidence and severity. LSD (P<0.01) values were used to separate treatments mean. Total weight of tubers per plot (kg) was show significant difference (P<0.01) among treatments. The highest total weight of tubers per plot (kg) was given by treated belete (T1) (22.625) followed by untreated belete (T3), untreated local (T4) and treated local (T2) (18.525, 11.875and 10.125) respectively (Table 2).  Local potato variety also gave the highest unmarketable tubers weight per plot. The result indicated that there were a significant difference (P<0.01) and (P<0.05) among treatments on late blight incidence and severity respectively. Untreated local variety (T4) showed highest late blight incidence and severity as compare to treated belete variety (T1). The experiment result suggested that application CurzateR R WP fungicide twice on variety belete results in significant reduction on late blight progress, with a corresponding increased tubers yield.

Author(s):  
Manju Evelyn Bi ◽  
Ache NehTeke ◽  
Nkwatoh Therese Ncheuveu ◽  
Bih Nadine Toh

Tomato late blight is an economic disease that causes 100 % yield loss of tomato in Cameroon. The objective of the study was to determine the efficacy of mancozeb and Ocimum gratissimum extract in managing late blight disease in Nadira and Rio-grande tomato varieties. Seedlings of each tomato variety were planted in replicates of three in a complete randomized block design comprising of three treatments (T1 –Ocimum gratissimum extract (1666.7 g/15 L); T2 –Mancozeb (50 g/15 L); T3 –control. Fifty grams of mancozeb (50g) and 1666.7 g of O. gratissimum extract dissolved and mixed with water in a 15 L knapsack sprayer was applied to control tomato late blight from the onset of blight symptoms, at two days intervals, to control Data for the disease incidence, severity, and yield parameters were collected at weekly intervals for four weeks from plants in the middle of the ridges.  Mancozeb and O. gratissimum extract significantly reduced the disease severity of  Nadira and Rio-grande tomato varieties by 0.2., resulting in a mean fruit number of 18.31 and 16.31 fruits and fruit weight of 1.44 g and 1.13 g. There was no significant difference (p =0.05) between plants sprayed with Mancozeb and O. gratissimum extract. The Nadira variety was resistant to the tomato late blight caused by Phytophthora infestans. Thus biopesticides (O. gratissimum) can be effectively used as alternatives to synthetic fungicides (mancozeb) –which pose risks to human and environmental health.


2020 ◽  
Vol 3 (1) ◽  
pp. 28-37
Author(s):  
Rishav Pandit ◽  
Ravi Bhatta ◽  
Pooja Bhusal ◽  
Basistha Acharya ◽  
Subash Subedi ◽  
...  

Developing host resistance is an economic and long-term approach to disease management; however, resistance reactions that differ depending on the genotypes. Potato late blight is the devastating disease caused due to Phytophthora infestans (Mont.) de Bary.  In order to identify late blight resistance in potato genotypes, seven local potato cultivars (Bardiya Rato Local, Bardiya Seto Local, Cardinal, Deukhuri Rato Local, Deukhuri Seto Local, Kailali Local and Khumal Ujjowal) were evaluated in randomized complete block design (RCBD) with three replications during October 2018 to January 2019 on naturally infested soils in Deukhuri, Dang, Nepal. Results showed that significantly the highest disease incidence (99.17%), and the highest disease severity (88%) were found on Cardinal followed by Deukhuri Rato Local (64%), and Deukhuri Seto Local (60%). Potato cultivar namely Khumal Ujjowal was moderately resistant, whereas Deukhuri Rato local and Deukhuri Seto Local were susceptible to late blight disease. Significantly the highest yield (12.67 t ha-1) was produced by Khumal Ujjowal followed by Bardiya Rato Local (10.78 t ha-1) and Bardiya Seto Local (9.40 t ha-1). The disease incidence and Area under disease progressive curve (AUDPC) value was negatively co-related with the tuber yield. The potato cultivar Khumal Ujjowal followed by Bardiya Rato Local were found moderately resistant to late blight disease in Deukhuri conditions. This study suggests that potato cultivar Bardiya Rato Local can be grown for higher tuber production in Dang and similar topographic regions.


2020 ◽  
Vol 3 (1) ◽  
pp. 28-37
Author(s):  
Rishav Pandit ◽  
Ravi Bhatta ◽  
Pooja Bhusal ◽  
Basistha Acharya ◽  
Subash Subedi ◽  
...  

Developing host resistance is an economic and long-term approach to disease management; however, resistance reactions that differ depending on the genotypes. Potato late blight is the devastating disease caused due to Phytophthora infestans (Mont.) de Bary.  In order to identify late blight resistance in potato genotypes, seven local potato cultivars (Bardiya Rato Local, Bardiya Seto Local, Cardinal, Deukhuri Rato Local, Deukhuri Seto Local, Kailali Local and Khumal Ujjowal) were evaluated in randomized complete block design (RCBD) with three replications during October 2018 to January 2019 on naturally infested soils in Deukhuri, Dang, Nepal. Results showed that significantly the highest disease incidence (99.17%), and the highest disease severity (88%) were found on Cardinal followed by Deukhuri Rato Local (64%), and Deukhuri Seto Local (60%). Potato cultivar namely Khumal Ujjowal was moderately resistant, whereas Deukhuri Rato local and Deukhuri Seto Local were susceptible to late blight disease. Significantly the highest yield (12.67 t ha-1) was produced by Khumal Ujjowal followed by Bardiya Rato Local (10.78 t ha-1) and Bardiya Seto Local (9.40 t ha-1). The disease incidence and Area under disease progressive curve (AUDPC) value was negatively co-related with the tuber yield. The potato cultivar Khumal Ujjowal followed by Bardiya Rato Local were found moderately resistant to late blight disease in Deukhuri conditions. This study suggests that potato cultivar Bardiya Rato Local can be grown for higher tuber production in Dang and similar topographic regions.


2016 ◽  
Vol 18 (2) ◽  
pp. 41
Author(s):  
Susiana Purwantisari ◽  
Achmadi Priyatmojo ◽  
Retno Peni Sancayaningsih ◽  
Rina Sri Kasiamdari

Late blight disease caused by Phytophthora infestans, is probably the single most important disease of potatoes worldwide. Infected plants were quickly killed and were difficult for replanting, causing significant losses for the growers. Various control methods were examined including the use of biocontrol agents of Trichoderma spp.  The biocontrol potential of Trichoderma viride against potato late blight pathogen, Phytophthora infestans, were studied  under greenhouse conditions. The research objective was to determine the ability of biocontrol agents Trichoderma viride to delay late blight disease incidence on potato plants in the field. The in vivo experiment was carried out at potato land area located at BALITSA in Cikole Sub District, Lembang District and Bandung Regency. Completely Randomized Design was used with six treatment and five replicates. The treatment tested consist of control (without pathogen fungal and antagonists fungus application too), control (with pathogen fungal application and without antagonist fungal application), chemical fungicide application, antagonist fungal application 2 weeks before planting, application 1 week after planting and both application 2 weeks before and 1 week after planting. Result of the research showed that application of antagonists fungal could delay disease intensity until 14 days. These antagonist could be used as biological agents initials to control leaf blight disease. Key words: Biological control, Potato late blight, Phytophthora infestans, Trichoderma viride


2021 ◽  
Author(s):  
Gebremariam Asaye Emrie ◽  
Merkuz Abera Admassu ◽  
Adane Tesfaye Lema

2020 ◽  
Author(s):  
Yuexin Li ◽  
Degang Zhao

Abstract Background: Late blight seriously threatens potato cultivation worldwide. The severe and widespread damage caused by the fungal pathogen can lead to drastic decreases in potato yield. Although grafting technology has been widely used to improve crop resistance, the effects of grafting on potato late blight resistance as well as the associated molecular mechanisms remain unclear. Therefore, we performed RNA transcriptome sequencing analysis and the late blight resistance testing of the scion when the potato late blight-resistant variety Qingshu 9 and the susceptible variety Favorita were used as the rootstock and scion, respectively, and vice versa. The objective of this study was to evaluate the influence of the rootstock on scion disease resistance and to clarify the related molecular mechanisms.Results: A Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that the expression levels of genes related to plant–pathogen interactions, plant mitogen-activated protein kinase (MAPK) signaling pathways, and plant hormone signal transduction pathways were significantly up-regulated in the scion when Qingshu 9 was used as the rootstock. These genes included late blight response genes encoding calcium-dependent protein kinases (CDPKs), chitin elicitor receptor kinases (CERKs), LRR receptor serine/threonine protein kinases (LRR-LRKs), NPR family proteins in the salicylic acid synthesis pathway, and MAPKs. When Favorita was used as the rootstock, the expression levels of the late blight response genes were not up-regulated in the Qingshu 9 scion, but the expression levels of the genes related to proline metabolism, fatty acid chain elongation, and diterpenoid biosynthesis pathways were down-regulated. Resistance results showed that self-grafting of the susceptible variety and grafting with the resistant variety as the rootstock increased the resistance of the susceptible scion to late blight. However, the resistance was stronger after grafting with the resistant variety as the rootstock. Using the susceptible variety as the rootstock decreased the late blight resistance of the resistant scion.Conclusions: Our results showed that changes to the expression of disease resistance genes in the scion after grafting are associated with late blight resistance. The results provide the basis for exploring the molecular mechanism underlying the effects of rootstocks on scion disease resistance.


2000 ◽  
Vol 11 (5) ◽  
pp. 181-185 ◽  
Author(s):  
K. V. Raman ◽  
Niklaus J. Grünwald ◽  
William E. Fry

2015 ◽  
Vol 26 (2) ◽  
pp. 103-108
Author(s):  
MM Anwar ◽  
A Parveen ◽  
MM Hossain ◽  
NU Mahamud ◽  
RK Roy

Potato cultivars grown in Bangladesh have low levels of general resistance to late blight. As such, most commercial potato farmers rely on fungicide applications for control of Phytophthora infestans, the causal agent of late blight. Management of late blight of potato requires an integrated approach that includes rotation with non-hosts, resistant cultivars, cultural practices, and fungicides. The study on efficacy of some new fungicides against late blight disease of potato was conducted at ARS, Alamnagar Rangpur during rabi season 2010-2011 to select suitable fungicides against late blight of potato. Thirteen different fungicides were tested and all the tested fungicides showed significantly better performance over control. Considering percentage disease incidence T4,T6 and T12 showed better performance than all other treatment. In case of T4,T6 and T12 treatment disease reduction was more than 80 % over control. Significantly the highest tuber yield 25.5 t ha-1was obtained from T3  which was statistically similar to the yield of T2,T5 , T6, T9, T10, T11and T12  treatment whereas the lowest tuber  yield 14.5 t ha-1 was obtained from control treatment. Field experiment was conducted from 2010 to 2011 to investigate the comparative efficacy of the fungicides. In the field, applications of fungicide that preceded the largest incremental increase in disease incidence provided the best control of disease or increased yield.Progressive Agriculture 26 (2): 103-108, 2015


1982 ◽  
Vol 60 (12) ◽  
pp. 2724-2728 ◽  
Author(s):  
B. Bradford ◽  
L. D. Moore ◽  
D. M. Orcutt

‘Nova’ and 'Beefsteak,' cultivars of tomato (Lycopersicon esculentum Mill.), were grown in chambers under light intensities of 240 or 120 μE∙m−2∙s−1. Thirty-five days after seeding, half of the tomato plants were harvested for sterol analysis and the others were inoculated with a tomato race O isolate of Phytophthora infestons (Mont.) de By. Late blight symptoms were assessed 10 days after inoculation from the number of leaves showing disease (disease incidence) and the amount of blighted area of each leaf (percent colonization). Disease incidence and percent colonization were not influenced by light intensity with 'Nova' plants, but 'Beefsteak' plants grown under low light were significantly [Formula: see text] more diseased than those exposed to the higher light intensity. Changes in free sterol, steryl ester, and total sterol concentrations between plants grown under different light intensities were similar for both cultivars. A significant decrease in the steryl glycoside concentration of low light grown 'Beefsteak' plants correlated with increased disease incidence. The possible role of steryl glycosides and their derivatives in late blight disease development is discussed.


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