scholarly journals Foliar Fungicides as Protective Seed Piece Treatments for Management of Late Blight of Potatoes

Plant Disease ◽  
1999 ◽  
Vol 83 (3) ◽  
pp. 265-268 ◽  
Author(s):  
Mary L. Powelson ◽  
Debra A. Inglis

Fungicides receiving Section 18 emergency exemptions for management of the foliar phase of late blight of potato were evaluated as protective treatments for control of tuberborne inoculum of Phytophthora infestans in greenhouse and field studies. Three Section 18 products, Acrobat MZ (dimethomorph + mancozeb), Curzate M-8 (cymoxanil + mancozeb), and Tattoo C (propamocarb hydrochloride + chlorothalonil), when applied to the seed piece prior to inoculation with P. infestans, significantly (P ≤ 0.05) increased sprout emergence, compared with the inoculated water control. Of the three Section 18 products, Curzate M-8 was frequently the most effective. The increase in plant emergence with the protective seed piece treatment was seen with cultivars that differ in susceptibility to late blight, two genotypes (US-8 and US-11) of P. infestans, zoospore and sporangial inocula, and at different inoculation sites on the seed piece. In greenhouse studies, percent emergence with the protective seed piece treatments averaged 74% for cv. White Rose and 44% for cv. Shepody, compared with 9 and 8% for the inoculated water control of the respective cultivars. In field studies, when inoculum was placed either adjacent to or 4 cm away from the sprout, plant emergence of the inoculated water control was 12 and 36%, respectively. Application of the fungicides to the seed piece prior to inoculation increased emergence by an average of 700 and 212% for the respective inoculation sites. There was no evidence for translocation of the fungicides to the emerging foliage in concentrations high enough to prevent foliar infection from airborne inoculum of P. infestans. Control of tuberborne inoculum of P. infestans with appropriate seed piece treatments will result in an increase in plant emergence and improved crop uniformity.

2008 ◽  
Vol 34 (1) ◽  
pp. 86-87 ◽  
Author(s):  
Bernardo A. Halfeld-Vieira ◽  
Reginaldo S. Romeiro ◽  
Ann Mounteer ◽  
Eduardo S.G. Mizubuti

The capacity of two bacteria isolated from the tomato phylloplane to control late blight (Phytophthora infestans) was investigated in the field, and compared against the effectiveness of spraying with the fungicide chlorothalonil (1.5 g a.i. L-1) or water (control). A 55% reduction in late blight intensity was observed in the leaves of the middle of the plant and 62% in those of the upper leaves when using the antagonist UFV-STB 6 (Novosphingobium capsulatum) as compared to the control. Isolate UFV-IEA 6 (Bacillus cereus) was able to reduce disease intensity by 55%, but only in the upper leaves of the tomato plants. Treatment with isolate UFV-STB 6 also led to a significant reduction in the percentage of fruits with late blight symptoms. The results demonstrate the potential of these two bacteria in controlling this disease.


Plant Disease ◽  
1998 ◽  
Vol 82 (4) ◽  
pp. 434-436 ◽  
Author(s):  
K. D. Marshall-Farrar ◽  
M. McGrath ◽  
R. V. James ◽  
W. R. Stevenson

Late blight of potato (Solanum tuberosum), caused by Phytophthora infestans, recently reappeared in Wisconsin and was a significant production problem in 1994. P. infestans isolates collected in Wisconsin from 1993 to 1995 were characterized for the following traits: mating type, sensitivity to metalaxyl, and allozyme genotype for Glucose-6-phosphate isomerase (Gpi). Characterization of these isolates revealed that a new, more aggressive population (A2 mating type, metalaxyl resistant, and Gpi genotype 100/111/122) is displacing the old population (A1 mating type, metalaxyl sensitive, and Gpi genotype 86/100) in Wisconsin.


Author(s):  
Abdul Majeed ◽  
Zahir Muhammad ◽  
Zabeeh Ullah ◽  
Rafi Ullah ◽  
Habib Ahmad

Potato (Solanum tuberosum L.) has been remained an important agricultural crop in resolving global food issues through decades. The crop has experienced enormous growth in terms of production throughout the world in recent decades because of improvement in agricultural mechanization, fertilizers application and irrigation practices. Nevertheless, a significant proportion of this valuable crop is still vulnerable to losses due to prevalence of different viral, bacterial, fungal and nematodes infestations. Late blight, caused by Phytophthora infestans (Mont.) de Bary, is one of the most threatening pathogenic diseases which not only results in direct crop losses but also cause farmers to embrace huge monetary expenses for disease control and preventive measures. The disease is well known for notorious ‘Irish Famine’ which resulted in drop of Irish population by more than 20% as result of hunger and potato starvation. Globally, annual losses of crop and money spend on fungicides for late blight control exceeds one trillion US dollars. This paper reviews the significance of late blight of potato and controlling strategies adopted for minimizing yield losses incurred by this disease by the use of synthetic fungicides. Advantages and disadvantages of fungicides application are discussed.


2017 ◽  
Vol 29 (2) ◽  
pp. 281
Author(s):  
Khalid Naveed ◽  
Nasir A. Rajputt ◽  
Sajid A. Khan ◽  
Arbab Ahmad

Phytophthora infestans is a destructive pathogen that causes late blight of potato worldwide. Several sexually and asexually reproducing lineages of the pathogen have been identified and new lineages are more virulent as compared to their parental lineages. A new highly aggressive clonal lineage EU13_A2 has spread into potato fields of Europe, Africa and Asia in place of the older lineages. In North America, 24 clonal lineages US1to US24 have been identified. Despite of sexual reproduction, the overall population of P. infestans in potato and tomato fields is dominated by asexual lineages. Breeding has been done to transfer 'R' genes into commercial potato cultivars through classical breeding and by pyramiding of genes. Defender is the only potato cultivar that has foliar and tuber resistance to late blight. Genetically modified potato with RB gene from Solanum bulbocastanum has been developed but it lacks tuber resistance to disease. This review discusses population structure of P. infestans worldwide and breeding efforts to produce late blight resistant potato.


2016 ◽  
Vol 8 (3) ◽  
pp. 1302-1305
Author(s):  
S. Dey ◽  
A. Chakraborty

An experiment was carried out to find out the influence of such agronomic practices on severity of the disease and to seek a proper cultural practice for management late blight of potato (Phytophthora infestans). The experimental results showed that the severity of late blight disease could be minimized by reducing the depth of irrigation (i.e. ¼ of irrigation channel). It was observed that the disease severity could be minimized by increasing the row-to-row and plant-to-plant spacing (60 × 25 cm). It was also observed that when less than recommended dose of nitrogenous fertilizer (200 Kg N/ha) along with slightly more than recommended dose of phosphorus and potassium fertilizer (200 Kg P2O5/ha and 250 Kg K2O/ha) was applied, severity and spread of the disease was found to be under check. Therefore, for better management of late blight of potato the proper agronomic practices should be integrated with the application of fungicides. This will not only reduce the number of sprays but also reduces the health hazards owing to application of fungicides.


Sign in / Sign up

Export Citation Format

Share Document