back to Country Profiles

This map displays primary areas of potato cultivation, based on area and yield data provided by province (four where significant potato cultivation occurs) by the Statistics Division, Ministry of Economic Affairs and Statistics, Government of Pakistan for the cropping year 2002 – 2003.

Punjab Province is by far the center of most potato production, accounting for over 100,000 hectares of a national total 115,000 hectares total cultivation. Within Punjab Province, cultivation is distributed with the greatest concentrations assigned to the districts of Sahiwal, Sialkot, Okara, Lahore, Jhang, and Kasur. Distribution to areas north of Punjab is assigned to areas below 3,000 meters above sea level.

 
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)?  

Late blight occurs on the plains of Punjab and the North West Frontier Province and, more recently, in the Balluchistan area and northern Pakistan, where the microclimate was previously considered unfavorable for development of the disease. The potato production areas are divided into 8 agro-ecological zones and LB is common in zones 2 to 6 [see map on following page] and very rare or absent in zones 1, 7, and 8 [See map on following page]. A late blight epidemic is not to be expected every season and depends on the coincidence of the optimal range of temperatures and sufficient rain. This usually occurs in the second half of the growing season.

The disease is primarily tuber borne, other sources are not unconfirmed.

                                 Potato production agro-ecological zones of Pakistan                         

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

Under favorable climatic conditions the epidemic can destroy the foliage within one month. The loss in yield varies mostly between 0–50 percent, but can be as high as 100 percent.

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

Late blight can be effectively controlled if contact fungicides are sprayed starting before the onset of the epidemic i.e., about 50–80 days after planting, at weekly intervals up to two weeks before harvest. This intervention is usually very economical resulting in marginal rates of returns of 200–1300 percent. Farmers have adopted this technology very well. More recently systemic fungicides like metalaxyl and other related compounds are being widely used now in various formulations for late blight control.

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

Research on the use of botanicals for late blight management has shown promising results. Among various neem based products, neem-seed oil was found very potent under in-vitro and green house tests.

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

While metalaxyl resistant isolates have been found throughout the potato-growing regions, intermediate isolates are more frequently detected.

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

The presence of both A1 and A2 mating types and resistance to metalaxyl is now reported. Race structure studies have indicated a high degree of genetic diversity in the population of P. infestans in different potato production areas. The P. infestans physiological races have three to four avirulence genes. The avirulence genes detected are R1, R3, R4 and R7. Genotypes of P. infestans that are unable to infect the potato differentials (for determining the presence of avirulence genes) have been identified. Of the isolates 75% had intermediate resistance to metalaxyl, 22.5% were resistant and 2.5% were sensitive.  

7. Disease risks and/or major needs?

All commercial varieties in use are susceptible to late blight.

8. Any publications on late blight in the country?  

I. Ahmad, J. I. Mirza, S. Batool. 2002. Metalaxyl Resistance in Pakistani Population of Phytophthora infestans (abstract). pp 129 in: Lizárraga C (ed), Late blight: Managing the global threat. Proceedings of the Global Initiative on Late Blight Conference, Hamburg, Germany, 11–13 July 2002. International Potato Center, Lima, Peru.

I. Ahmad, S. Batool, J. I. Mirza. 2002. Distribution of Mating Types of Phytophthora infestans in Pakistan (abstract). pp 129 in: Lizárraga C (ed), Late blight: Managing the global threat. Proceedings of the Global Initiative on Late Blight Conference, Hamburg, Germany, 11–13 July 2002. International Potato Center, Lima, Peru.

S. Iram, I. Ahmad, S. Batool, S. Masood. Protein profiles of Phytophthora infestans isolates collected from potato production zones of Pakistan (abstract). pp 136 in: Lizárraga C (ed), Late blight: Managing the global threat. Proceedings of the Global Initiative on Late Blight Conference, Hamburg, Germany, 11–13 July 2002. International Potato Center, Lima, Peru.

GILB Annual Report 2000. 2001. pp 7–9 GILB Linkage Groups, Southwest Asia. International Potato Center (CIP), Lima, Peru.

9. Is tuber blight an increasing problem?

Yes it is a problem.

10. Other comments

All commercial varieties in use are susceptible to late blight. New genetic stocks have been screened for late blight resistance and encouraging results obtained. Some clones from the International Potato Center (CIP) were found resistant and are being further tested for release as varieties

Contact: Iftikhar Ahmad, Crop Disease Research Institute, National Agricultural Research Centre  (NARC), Islamabad, Pakistan. Email: iftahmad(at)isb.paknet.com.pk

Links to World Potato Atlas (WPA)

http://research.cip.cgiar.org/confluence/display/wpa/Pakistan