Metalaxyl resistance, mating type and pathogenicity of Phytophthora infestans in Uganda

Mukalazi, J.; Adipala, E.; Sengooba, T.; Hakiza, J. J.; Olanya, Modesto; Kidanemariam, H. M.

doi:10.1016/s0261-2194(00)00145-9

Cited by 50 publications

(23 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ineffectiveness of metalaxyl in Peru may be somewhat masked by mixture with a contact fungicide and this may explain why it is still used. Indeed, metalaxyl-M and the former metalaxyl are still used in other locations where research has demonstrated insensitivity in the pathogen population (Mukalazi et al 2001). Field experiments are needed to relate the results of laboratory and greenhouse studies to practical performance of metalaxyl-M.…”

Section: Discussionmentioning

confidence: 99%

Resistance to metalaxyl-M and cymoxanil in a dominant clonal lineage of Phytophthora infestans in Huánuco, Peru, an area of continuous potato production

2009

View full text Add to dashboard Cite

Fifty-eight isolates of Phytophthora infestans were evaluated in vitro and on detached leaves of potato for their sensitivities to metalaxyl-M and cymoxanil. The isolates belonged to the clonal lineage, EC-1, which is dominant on potato in Peru and Ecuador. All isolates were collected in Huánuco, Peru, an area of year-round potato production, where the potential for development of fungicide resistance is high. All isolates were resistant to metalaxyl-M, with in vitro EC 50 values ranging from 468.30-813.57 mg l −1 . In contrast, we found no evidence for resistance to cymoxanil for which in vitro EC 50 values ranged from 0.03-1.11 mg l −1 . Resistance to each fungicide was also evaluated for five isolates in a detached leaf assay in which the fungicide was sprayed on the leaf surface prior to inoculation. With metalaxyl-M, the range of EC 50 values was 158.85-828.29 mg l −1 , similar to that for the in vitro assay. For cymoxanil, EC 50 values ranged from 1.41 to 2.31 mg l −1 , which was higher than in the in vitro assay but still two orders of magnitude lower than the concentration applied by farmers in the field.

show abstract

Section: Discussionmentioning

confidence: 99%

Resistance to metalaxyl-M and cymoxanil in a dominant clonal lineage of Phytophthora infestans in Huánuco, Peru, an area of continuous potato production

2009

View full text Add to dashboard Cite

show abstract

“…Systemic fungicides can reach deeper parts of the host plant and they remain active longer. Applications of systemic fungicides are made beginning 60 days after planting with up to 3 applications at 10-day intervals (Deahl et al, 1993;Mukalazi et al, 2001;Mantecon, 2007). In addition to contact and systemic fungicides, local and acropetal penetrants are also used which for some protective barriers on and with penetration to host tissues (Jung et al, 2007).…”

Section: Nature and Mode Of Activitymentioning

confidence: 99%

Late Blight of Potato (Phytophthora infestans) I: Fungicides Application and Associated Challenges

Majeed

Muhammad

Ullah

et al. 2017

Turkish JAF Sci.Tech.

View full text Add to dashboard Cite

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.

show abstract

“…After the leaflets had dried (1 h) they were then inoculated using the method described by Mukalazi et al (2001). One drop (50 µL, 2×10 4 spores/mL) of sporangial suspension was applied to the midrib of the leaflet using a Pasteur pipette.…”

Section: Inhibition Of P Infestans On Detached Leafletsmentioning

confidence: 99%

“…As a consequence, there are currently only a few tomato and potato varieties that are moderately resistant to late blight. Metalaxyl resistance has been observed in Cameroon (Fontem et al, 2005) and elsewhere (Lee et al, 1999;Mukalazi et al, 2001). Other control measures such as cultural and physical methods have been found to be of low efficiency, high cost and difficult to implement in an Article published by EDP Sciences and available at http://www.agronomy-journal.org or http://dx.doi.org/10.1051/agro:2008036 extensive area, especially in developing countries (Schippers, 2004).…”

Section: Introductionmentioning

confidence: 98%

High efficacy of extracts of Cameroon plants against tomato late blight disease

Goufo

Mofor

Fontem

et al. 2008

Agron. Sustain. Dev.

View full text Add to dashboard Cite

-The classical protection of tomato plants against the late blight disease caused by the fungi Phytophthora infestans involves the use of synthetic fungicides. However, such a practice raises two major issues. First, synthetic fungicides are toxic substances that are a threat to the ecosystem. Second, the efficiency of synthetic fungicides is decreasing due to the development of fungicide resistance by the fungi. In addition, there is growing concern from consumers about food contamination due to heavy reliance on toxic and persistent chemicals in plant protection strategies. Therefore, there is a necessity to evaluate the efficacy of alternative compounds. Biologically active products occur in plants for protection against pests, pathogens and other plants. Such compounds could be valuable as biopesticides for controlling plant diseases because they are biodegradable and selective in their activities. In that context, we conducted laboratory and greenhouse experiments to assess the efficacy of nine extracts of native plants of Cameroon in controlling P. infestans. Sporangial germination was determined after 24 h of incubation on 1.5% water agar medium at 18• C in the dark. Lesion size, and late blight latency and severity were assessed on 7-8-week-old detached leaflets and whole tomato plants incubated in the greenhouse for 7 days. Our results showed that Cupressus benthamii and Vetiveria zizanioides extracts were the most effective preparations, leading to 23% and 35% inhibition of sporangial germination, respectively, and to 86% and 77% disease reduction. A clear relationship between disease latency and disease severity was established. The identification of C. benthamii and V. zizanioides extracts as potential alternate compounds for late blight control is a major step in the process of replacing harmful pesticides. Using these biopesticides in combination with other established disease management practices could help control late blight in a more sustainable and environmentally friendly way. plant extracts / Phytophthora infestans / late blight / tomato / antifungal activity / disease suppression / biopesticide

show abstract

Metalaxyl resistance, mating type and pathogenicity of Phytophthora infestans in Uganda

Cited by 50 publications

References 19 publications

Resistance to metalaxyl-M and cymoxanil in a dominant clonal lineage of Phytophthora infestans in Huánuco, Peru, an area of continuous potato production

Resistance to metalaxyl-M and cymoxanil in a dominant clonal lineage of Phytophthora infestans in Huánuco, Peru, an area of continuous potato production

Late Blight of Potato (Phytophthora infestans) I: Fungicides Application and Associated Challenges

High efficacy of extracts of Cameroon plants against tomato late blight disease

Contact Info

Product

Resources

About