Epidemiology and Integrated Control of Potato Late Blight in Europe

Abstract

Phytophthora infestans, the causal agent of late blight, is a major threat to potato production in northwestern Europe. Before 1980, the worldwide population of P. infestans outside Mexico appeared to be asexual and to consist of a single clonal lineage of A1 mating type characterized by a single genotype. It is widely believed that new strains migrated into Europe in 1976 and that this led to subsequent population changes including the introduction of the A2 mating type. The population characteristics of recently collected isolates in NW Europe show a diverse population including both mating types, sexual reproduction and oospores, although differences are observed between regions. Although it is difficult to find direct evidence that new strains are more aggressive, there are several indications from experiments and field epidemics that the aggressiveness of P. infestans has increased in the past 20 years. The relative importance of the different primary inoculum sources and specific measures for reducing their role, such as covering dumps with plastic and preventing seed tubers from becoming infected, is described for the different regions. In NW Europe, varieties with greater resistance tend not to be grown on a large scale. From the grower's perspective, the savings in fungicide input that can be achieved with these varieties are not compensated by the higher (perceived) risk of blight. Fungicides play a crucial role in the integrated control of late blight. The spray strategies in NW Europe and a table of the specific attributes of the most important fungicides in Europe are presented. The development and use of decision support systems (DSSs) in NW Europe are described. In The Netherlands, it is estimated that almost 40% of potato growers use recommendations based on commercially available DSS. In the Nordic countries, a new DSS concept with a fixed 7-day spray interval and a variable dose rate is being tested. In the UK, commercially available DSSs are used for c. 8% of the area. The validity of Smith Periods for the new population of P. infestans in the UK is currently being evaluated.

Can Precision Agriculture Increase the Profitability and Sustainability of the Production of Potatoes and Olives?

“…In this mode, a decision is made when (if at all) to perform an operation, for example to control weeds [16,17], to control late blight [18], or to control plant parasitic nematodes [9].…”

The Effect of Growth Regulators and a Biostimulator on the Health Status, Yield and Yield Components of Potatoes (Solanum tuberosum L.)

“…Yield losses caused by early blight are generally estimated at 20%, but they can reach 70-80% in unprotected potato farms (Soleimani and Kirk 2012) (Kapsa and Hansen 2004). Crop losses can also be minimized by cultivating potato cultivars that are more resistant to pathogens (Cooke et al 2011). Potato cultivars with colored flesh contain 2 to 10 times more phenolic acids than traditional cultivars with yellow flesh (Brown 2005;Hamouz et al 2010;Ezekiel et al 2013;Bellumori et al 2017), and they are more resistant to stressors, including pathogens (Tierno and Ruiz de Galarreta 2016).…”

Effect of the spray volume adjustment model on the efficiency of fungicides and residues in processing tomato

“…However, this study cannot confirm directly this thesis. Studies on other crops (Walklate et al, 2003;Dammer et al, 2008;Llorens et al, 2011), including potato (Cooke et al, 2011) indicate that crop and canopy characteristics modify the fungicide rate per leaf surface area unit and could affect fungicide efficiency.…”

“…Various studies showed a close relation between meteorological parameters of ambient air and PLB incidence on potato and tomato (Harrison, 1992;Sharma 2000). However, foliage abundance, agrotechnique, including crop irrigation, influence the meteorological conditions inside canopy, hence PLB potential (Olanya et al, 2007;Cooke et al, 2011). On the other hand, host resistance diminished PLB risk (Duvauchelle & Dubois, 2001).…”