back to Country Profiles

For further information on Potato Production  click here

1. Late blight occurrence and LB severity by major production area in the country. What crops were affected (tomato, potato, others)? Disease sources (seed, cull piles, volunteer plants, soil)?

Data for 2002²

In Wallonia, the southern highlands, the initial inoculum pressure was again very high. The high level of infection at the end of 2001 probably resulted in many blighted tubers (seed, waste piles, volunteers). The winter was again relatively mild enabling potatoes to survive in the soil and develop into volunteer (first symptoms observed 15 June) plants in 2002. In this part of the country uncovered dumps (first symptoms observed 15 May), home gardens and early potatoes under plastic are also important sources of primary inoculum. The weather conditions were very conducive for LB from mid June till the end of august. At mid July, it was possible to find symptoms in most of commercial crops; some case of severe attacks appeared but generally, the conditions were good for the application of fungicides.  In September, the conditions for harvesting were optimal. Heavy rains in the end of August were very favourable to the tuber infection.

In Flanders, the northern region, late blight was first observed on a dump pile (29 April). More lesions were observed in the first half of May — all on dump piles. From 21 March until the end of April, weather conditions were dry and sunny, suitable for early planting, but not for late blight. The end of April and beginning of May were wetter and more suitable for the disease (some attacks were observed), but the rest of May until half of June was only moderately favorable for the disease. Moreover, spraying conditions were good and the crops could be effectively protected with protectant treatments. High temperatures combined with high humidity and rainfall after 15 June caused light but widespread attacks of late blight. From then on until the end of August, weather conditions were mostly favourable for a high to very high disease pressure.

2. LB impact (foliar damage, yield losses, tuber rot occurrences)?

Data for 2002²

In Flanders, September was relatively dry, leading to good conditions for crop lifting. However, a considerable degree of tuber rot and tuber blight was observed later in the storage season. The very high rainfall during the second half of August led to a higher incidence of tuber rot and tuber blight than initially expected.  

3. Fungicide use (amounts, types, etc.)?

Data for 2002²

In Flanders blight was controlled in cultivar Bintje with an average of 13 applications. In July more than 60% of the applications was made with cymoxanil or dimethomorph containing products. Almost no phenylamides were used. Towards the end of August, crop senescence was already considerable and a lot of fields died off naturally. Fentin containing products were on average sprayed more than 4 times.

The numbers of sprays were estimated as 11-13 in 2001 in both Wallonia and Flanders. In 2002 sprays increased to 12 to 14 in Flanders and 12 to 16 in Wallonia.

4. Other LB control measures (resistant cultivars, forecast systems, none)?

Forecasting systems based on the disease forecasting model of Guntz-Divoux are used both in Flanders and Wallonia. Automatic weather stations provide meteorological data. Farmers are also advised on fungicide use and cultivar susceptibility in order to reduce protection for the more resistant culitvars.

5. LB control effectiveness (fungicide or host resistance failures)?  

Data for 2002²

One case of rapid destruction of Gasore was reported in mid July. Gasore is grown only in the private backyards and for small size tubers special productions for industry.

6. Pathogen strains (mating type, fungicide resistance, virulence factors, etc)?

In a study during 1995 one A2 mating type isolate was found in a commercial potato field and it was resistant to metalaxyl. The other nine isolates studied were of the A1 mating type. Using Glucose-6 phosphate isomerase and Peptidase allozyme analysis, two genotypes were determined for the A1 isolates: Gpi 90/100, Pep 83/100 (60%) and Gpi 90/100, Pep 100/100. The A2 isolate allozyme genotype was Gpi 90/100, Pep 100/100. The most common virulence pattern was 1.3.4.7.10.11.

In studies in Wallonia during the 1999, 2000 and 2001 cropping seasons (see table below) about one of five isolates was found to belong to the A2 mating type, 17%, 18% and 20% respectively. Resistance to metalaxyl is widespread and appears early at the beginning of the growing season. The majority of the pathotypes are complex.

Table 1. Resistance to metalaxyl, mating type and virulence of Phytophthora infestans isolates, Wallonia, 1999, 2000 and 2001 cropping seasons.

7. Disease risks and/or major needs?

8. Any publications on late blight in the country?  

Ducattillon C. 2000. Late blight warning in Hainaut: advising and application of potato varieties sensitivity. pp 156–158: in: Schepers H (ed), Proceedings of the Workshop on the European network for development of an Integrated Control Strategy of potato late blight, 29 September – 2 October 1999, Oostende, Belgium, PAV-Report no. 6. Applied Research for Arable Farming and Field Production of Vegetables, Lelystad, Netherlands.

Goeminne M, Vanderhaverbeke P and Ampe G. 1997. Experiences with late blight warning services in Flanders. pp 52–60 in: Bouma E and Schepers H T A M (eds), Proceedings of the Workshop on the European network for development of an Integrated Control Strategy of potato late blight, 30 September – 3 October 1996, Lelystad, The Netherlands, PAV-Report no. 1. Applied Research for Arable Farming and Field Production of Vegetables, Lelystad, Netherlands.

Haine D and Michelante D. 2002. Late blight populations in Wallonia in 2000: mating type, metalaxyl resistance, pathotypes and aggressiveness. pp 243–252 in: Westerdijk C E and Schepers H T A M (eds), Proceedings of the Sixth Workshop of an European Network for development of an Integrated Control Strategy of potato late blight, 26–30, September 2001 , Edinburgh, Scotland, PPO-Special Report no. 8. Applied Plant Research BV, Wageningen, Netherlands.

Hansen J G, Kleinhenz B, Jörg E, Wander J G N, Spits H G, Dowley L, Rauscher E, Michelante D, Dubois L and Steenblock T. 2002. Results of validation trials of Phytophthora DSSs in Europe, 2001. pp 231–242 in: Westerdijk C E and Schepers H T A M (eds), Proceedings of the Sixth Workshop of an European Network for development of an Integrated Control Strategy of potato late blight, 26–30, September 2001 , Edinburgh, Scotland, PPO-Special Report no. 8. Applied Plant Research BV, Wageningen, Netherlands.

Hansen J G, Kleinhenz and Jörg E. 2001. Results of validation trials of Phytophthora DSS in Europe in 2000. pp 23–38 in: Westerdijk K and Schepers H T A M (eds), Proceedings of the Workshop on the European network for development of an Integrated Control Strategy of potato late blight, 6–10 September 2000, Munich, Germany, PAV-Special Report no. 7. Applied Research for Arable Farming and Field Production of Vegetables, Lellystad, Netherlands

Heremans B and Lamart G. 2000. Genetic structure of the late blight population in Belgium. pp 55–60 in: Schepers H (ed), Proceedings of the Workshop on the European network for development of an Integrated Control Strategy of potato late blight, 29 September – 2 October 1999, Oostende, Belgium, PAV-Report no. 6. Applied Research for Arable Farming and Field Production of Vegetables, Lelystad, Netherlands.

Kleinhenz B and Jörg E. 2000. Results of Validation Trials of Phytophthora DSS in Europe in 1999. pp 180–190 in: Schepers H (ed), Proceedings of the Workshop on the European network for development of an Integrated Control Strategy of potato late blight, 29 September – 2 October 1999, Oostende, Belgium, PAV-Special Report no. 6. Applied Research for Arable Farming and Field Production of Vegetables, Lelystad, Netherlands.

Lebreton, L. Duvauchelle, S. Andrivon, D. 1996. Occurrence in France and Belgium of A2 mating type isolates of Phytophthora infestans in 1995. Abstracts of conference papers, posters and demonstrations, 13th Triennial Conference of the European Association for Potato Research, 14–19 July 1996, Veldhoven, The Netherlands.

Michelante D, Haine D, Verlaine A. 2003. Validation of integrated control strategies including Guntz-Divoux based DSSs and cultivars. pp 73–79 in: Westerdijk C E and Schepers H T A M (eds). Proceedings of the 7^th Workshop on the European network for development of an integrated control strategy of potato late blight, 2–6 October 2002, Poznan, Poland, PPO-Special Report no. 9. Applied Plant Research BV, Wageningen, The Netherlands.

Michelante D, Rossion L, Deveux L and Rolot J.-L. 2001. Mating types, metalaxyl resistance and pathotypes of Phytophthora infestans in Wallonia – 1999. pp 265–269 in: Westerdijk K and Schepers H T A M (eds), Proceedings of the Workshop on the European network for development of an Integrated Control Strategy of potato late blight, 6–10 September 2000, Munich, Germany, PAV-Special Report no. 7. Applied Research for Arable Farming and Field Production of Vegetables, Lelystad, Netherlands.

Michelante D, Rolot R L and Verlaine A. 2000. Integrated control of late blight in conventional and organic potato production using warnings and cultivars resistance: results 1998–1999. pp 191–200 in: Schepers H (ed), Proceedings of the Workshop on the European network for development of an Integrated Control Strategy of potato late blight, 29 September – 2 October 1999, Oostende, Belgium, PAV-Report no. 6. Applied Research for Arable Farming and Field Production of Vegetables, Lelystad, Netherlands

Michelante D, Rolot J L and Verlaine A. 1999. Late blight forecast and control in Wallonie. pp 283–289 in: Schepers H and Bouma E (eds), Proceedings of the Workshop on the European network for development of an Integrated Control Strategy of potato late blight, 9–13 September 1998, Uppsala, Sweden, PAV-Report no. 5. Applied Research for Arable Farming and Field Production of Vegetables, Lelystad, Netherlands.

Rolot J-L, Michelante D and Verlaine A. 1998. Discussion on validity of decision support system for potato late blight in Wallonia. pp 111–124 in: Schepers H and Bouma E (eds), Proceedings of the Workshop on the European network for development of an Integrated Control Strategy of potato late blight, 24–27 September 1997, Carlow Ireland, PAV-Report no. 3. Applied Research for Arable Farming and Field Production of Vegetables, Lelystad, Netherlands.

Rolot J L, Verlaine A and Meeus P. 1997. Potato late blight: Development of a warning service at the “station de haute Belgique”. pp 25–43 in: Bouma E and Schepers H T A M (eds), Proceedings of the Workshop on the European network for development of an Integrated Control Strategy of potato late blight, 30 September – 3 October 1996, Lelystad, The Netherlands, PAV-Report no. 1. Applied Research for Arable Farming and Field Production of Vegetables, Lelystad, Netherlands

9. Is tuber blight an increasing problem?

Yes

 
Contact: David Michelante, Agricultural Research Center, Wallonia, Belgium (michelante(at)cra.wallonie.be)

[2] Schepers, H T A M. 2003. The development and control of Phytophthora infestans in Europe in 2002. pp 9–22 in: Westerdijk C E and Schepers H T A M (eds), Proceedings of the Seventh Workshop of an European Network for development of an Integrated Control Strategy of potato late blight, 2–6, October 2002 , Pozan, Poland, PPO-Special Report no. 9. Applied Plant Research BV, Wageningen, Netherlands. Information regarding the late blight epidemic in 2002 in Belgium provided by D. Haine and P. Vanhaverbeke.