Potato Production in China and Norway:Similarities, Differences and Future Challenges

Arne Hermansen & Dianqiu Lu & Greg Forbes

Received: 16 September 2012 /Accepted: 17 September 2012 /Published online: 20 October 2012# EAPR 2012

Keywords China . Diseases . Norway . Pests . Potato production

Potato production—area, yield and use

Potato is the third most important food crop in the world after rice and wheat in terms ofhuman consumption. More than a billion people worldwide eat potato, and global totalcrop production exceeds 300 million metric tons (http://www.cipotato.org/potato).

Potato is also an important crop in Norway and China. Norway has approxi-mately five million inhabitants while China has 1.4 billion inhabitants. Potatoproduction in the two countries is of similar importance relative to their respectivepopulation sizes.

China has the highest production of potato in the world according to figuresfrom FAO in 2009, with 4,753 millionha planted to the crop, which is 25.93%of the total global potato area. China produces 69 million tons of potato, whichis 21% of the total global output of this crop. Due to the adaptability andtolerance of the potato plant to drought, cold climate and infertile soils, it cangrow in most regions in China and is widely grown in almost all provinces. In2010, potato acreage was over 333,000 ha in the following provinces, autono-mous regions and municipalities: Inner Mongolia, Guizhou, Gansu, Sichuan,

Potato Research (2012) 55:197–203DOI 10.1007/s11540-012-9224-7

A. Hermansen (*)Bioforsk—Norwegian Institute for Agricultural and Environmental Research,Plant Health and Plant Protection Division, N-1432 Ås, Norwaye-mail: arne.hermansen@bioforsk.no

D. LuHeilongjiang Academy of Agricultural Sciences, Virus-Free Seedling Research Institute,Harbin 150086, People’s Republic of China

G. ForbesInternational Potato Center, Beijing, People’s Republic of China

Yunnan and Chongqing. The area planted in these locations was 3.377 millionha, accounting for 65% of the total potato area in the country. Because ofdifferences in climate, soil, geography and production management in differentregions, potato cultivars and cultivation methods vary substantially. In China,potato is mainly used for fresh consumption, with only about 10% used forprocessing. There are about 5,000 potato-processing enterprises in the country,among which some 150 are quite large and advanced. The nationwide processingcapacity is around two million tons for starch, 100,000 tons for potato flakes and250,000 tons for French fries.

In 2010, potatoes were grown on 13,212 ha in Norway, resulting in a total ofapproximately 321,000 tons of potatoes and a wholesale value of approximately 73million Euro. If we divide the use of potatoes per capita, 20 kg is used for directconsumption, 25 kg for processed potato products like potato chips and French fries,8 kg for potato flour and glucose and 4 kg for alcohol.

The structure of the potato production in Norway has changed dramatically duringthe last 20 years. The potato-growing area has decreased by approximately 30%, andthe number of growers has decreased by more than 90%; Norway had only 2,765potato growers in 2010. The average potato area per farm was 0.5 ha in 1989 and4.8 ha in 2010.

The potato crop is grown in all counties in Norway including the most northerncounty Finnmark (latitude, 70°N).

Potato Cultivars

According to incomplete statistics, between 1998 and 2009, a total of 165 newvarieties of potato were registered in China, among which 34 were released nationallyand 131 at the provincial level. Potato varieties grown on a large area includedKexing 1, Weiyu 3, Favourite, Mira, Longshu 3, Hui-2, Er-Potato 3, Qingshu 168,Dongnong 303, Hutou and Cooperation 88 (Li et al. 2011). Due to the large potato-growing area and huge regional differences in the natural environment, many varie-ties possess a certain regional adaptability. Currently, few cultivars are suitable forstarch processing and French fries.

About 10 years ago, 50% of the potato area in Norway was cropped withNorwegian-bred cultivars, but now, the area of Norwegian cultivars is down toapproximately 25%. The choice of cultivars has been in favour of those originatingfrom the Netherlands or Denmark. In the 2011 season, Saturna, Asterix, Mandel,Folva and Beate were the most widely used cultivars (Møllerhagen 2012).

Seed Potato Production and Sanitary Regulations

Shoot tip culture is the main approach in China to obtain virus-free seedlings,which are grown in greenhouses or nethouses for mass propagation. Seedpotato is largely produced in the high-latitude and high-altitude areas in thenorth and southwest provinces, but seed production currently is not wellorganized or coordinated. Only 25–30% of the seed potatoes used are quality

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seed. In recent years, more quality seed potatoes have been used due to thegovernment encouraging policy and development of seed production technolo-gy. In order to maintain seed quality, a three-level system for seed potatopropagation is now widely used for virus-free potato production. Seed potatoquality testing is conducted in the Supervision and Testing Center for Virus-Free Seed Potato Quality (STCVSPQ) affiliated to the Chinese Ministry ofAgriculture. However, the seed potato inspection and certification system isfar from perfect, and there is truly no effective seed quality control system andmarket access system in China. In 1987, the Plant Quarantine Rules for PotatoSeed Tuber Producing Areas (GB 7331-87) was issued, and in 2003, the ruleswere revised. In 2000, the State introduced the first national standard for virus-free seed potato ‘Certified Seed Potatoes’ (GB18133-2000), and in 2008, thestandard was revised and has now become a basis for seed quality testing.

In Norway, about 20% of the seed potatoes used are certified. The certifi-cation system is carried out according to a law managed by the NorwegianFood Safety Authority. According to other rules in the same law, importation ofseed potatoes to Norway is not allowed. This is to secure a high plant sanitarystandard. It has been possible to keep this regulation since Norway is not partof the European Union.

Pest and Disease Problems

Fungal and Fungal-Like Diseases

Potato late blight (Phytophthora infestans), early blight (Alternaria solani) andRhizoctonia (Rhizoctonia solani) are the main fungal and ‘fungal-like’ (as P. infestansis an oomycete) diseases of potato in China. Late blight is the most serious anddevastating disease. It occurs in almost all potato-producing areas in the country.Usually, late blight causes an annual loss of 10% to 30%, while in specific locationswhere disease is severe, complete crop loss is possible. Currently, growing resistantcultivars, selection of disease-free seed potato and fungicide application are the mainapproaches for disease control, among which the most effective method is chemicalcontrol. Recently, potato late blight forecasting techniques are being evaluated inseveral locations in the country.

Damages caused by early blight have increased significantly in recent years inChina. The disease occurs in the main potato-growing areas in varying degrees. Thisdisease frequently causes severe production loss (15–30%), while infection rate insome potato plots can be 100%. In some areas, its damage is as serious as that causedby late blight.

With continuous potato in consecutive seasons in the same field, Rhizoctoniadiseases have become quite serious. In China, dry rot of potato (Fusarium spp.) isan important storage disease also having an impact on plant emergence.

The main potato disease in Norway is potato late blight. The yearly cost of thisdisease is about 7–9 million Euro (Sæthre et al. 2006), including both losses andfungicide applications. The gross yield reduction in conventional production isnormally small compared to losses caused by infection in the tubers. Most potato-

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packing companies and some of the potato-processing industries have a ‘zero toler-ance’ to tuber blight. There are several other fungal pathogens that might attack theaboveground potato organs such as Botrytis cinerea, Sclerotinia sclerotiorum, A.solani and Verticillium spp., but these are only occurring sporadically and normallycause minor problems.

There are no other fungal diseases that normally cause yield reduction in Norway.However soil-borne pathogens as R. solani might alter the size distribution of theyield and also cause black scurf. Several other fungal pathogens might also cause skinblemish diseases and reduce tuber quality. Among these, silver scurf caused byHelminthosporium solani is the most prevalent one in Norway (Nærstad et al. 2012).

The two most common postharvest diseases are gangrene (Boeremia foveata) andFusarium dry rot caused by different Fusarium species. Potato wart, caused bySynchytrium endobioticum, has been known in Norway since 1914 and is a quaran-tine disease under regulatory control. Because of these rules and use of mainlyresistant cultivars, this disease has not been found in Norway since 1994.

Bacterial Diseases

Potato bacterial wilt, ring rot, black leg and soft rot are the major bacterial diseases inChina. Bacterial wilt mainly occurs in the southern region of the country while ringrot largely takes place in the northern regions. Due to continuous cropping and use ofinfected seed, the incidence of black leg disease increases year by year. The disease ofsoft rot also causes a huge loss during potato storage.

Ring rot caused by Clavibacter michiganensis subsp. sepedonicus is a quarantinedisease under regulatory control in Norway and has been known in the country since1964 (Perminow et al. 2012). Ralstonia solanacearum causing brown rot is not foundin Norway. Soft rot and black leg caused by Pectobacterium atrosepticum andPectobacterium carotovorum are common bacterial diseases in Norway. Dickeyasolani has so far not been detected in Norway. Common scab caused byStreptomyces spp. is one of the most important scab and scurf diseases in Norway(Nærstad et al. 2012).

Virus Diseases

Virus diseases are the major threats to the quality of the seed potatoes, therebycausing significant yield loss through the process of degeneration. Six different potatoviruses (PVX, PVY, PVS, PVM, PVA and PLRV) are commonly found in potato inChina. According to the data of STCVSPQ (Harbin), in 2010, the following viruseswere found, in descending order of incidence: PVY, PVS, PVM, PLRV, PVX andPVA. Quarantine virus diseases, such as PVV, TBRV, PMTV, TRV, PYDV, were notdetected, although potato spindle tuber viroid (PSTVd) occurred commonly in warepotato-growing areas in northern China.

The aphid-transmitted viruses found in Norway are PVA, PVM, PVS, PVV andPVY. Among these, PVY is the most important potato virus in Norway because of itsprevalence and its potential for high reduction of the yield. The mechanicallytransmitted PVX was common earlier, but is now very rare in the certified seedsystem, but probably still prevalent in old seed stocks.

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In Norway, two soil-borne viruses are common: Potato mop-top virus transmittedby the fungus Spongospora subterranea and Tobacco rattle virus transmitted bystubby-root nematodes (Trichodorus spp. and Paratrichodorus spp.).

Nematodes

Potato cyst nematodes (PCN), including Globodera rostochiensis and G. pallida are agroup of devastating pests on potato and also are important quarantine pests. InChina, they are not found, and the seed potatoes from the infected countries have longbeen banned.

PCN are quarantine organisms under regulatory control in Norway. Themost common species is G. rostochiensis and is found in several of the potato-growing areas in the country. G. pallida is less common. Root lesion nematodescaused by either Pratylenchus penetrans, Pratylenchus crenatus or Pratylenchusfallax are found in all parts of the country (Holgado and Magnusson 2012). Inaddition to yield reduction, P. penetrans also probably interacts with Streptomycesspp. causing scab-like tuber symptoms (Nærstad et al. 2012). Potato rot nematodescaused by Dithylenchus destructor and stubby-root nematodes (Trichodorus andParatrichodorus) are also found in Norway but are of minor importance, except thelatter as vector for Tobacco rattle virus (see above) (Holgado and Magnusson 2012).

Pests

There are several arthropods and other pests in China, including 28 spot ladybug,aphids, whitefly, thrips, mites, leaf miners, potato tuber moth, cutworms, grubs, molecrickets and wireworms. Among them, the first two and soil pests (cutworms, grubs,mole crickets, wireworms) cause the greatest loss of production. Pest damage,although occurring throughout the country, is more serious in the north than in thesouth. Aphids, as vectors for many viruses, are crucial for seed potato virus diseasecontrol. Many aphid-monitoring stations have been established across the country forbetter control.

In Norway, potato leaf hopper (Empoasca vitis) is a common insect in potato in thesouthern part of the country and can sometimes reduce the yield substantially. Aphidsare the most important virus vectors and are found in different potato districts, mainlyin the southern parts of the country. Recently, a survey has started to identify the mostimportant aphid species in important potato districts in Norway (Klingen et al. 2012).

Use of Pesticides Against Pests and Diseases

Chemical application is the primary means to control potato pests and diseases inChina. Development of pest monitoring and forecasting techniques ensures chemicalcontrol of potato pests and diseases efficiently. In some cases, fungicides are usedexcessively, especially for seed production.

Fungicide applications against late blight constitute by far the most important use ofpesticides in potatoes in Norway. On average, for the period 2000–2004, potato fieldswere treated with fungicides 5.6 times per season to control this disease (Sæthre et al.

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2006). For correct timing of applications, a late blight forecasting system is availablefor potato growers via the internet-based system VIPS (www.vips-landbruk.no).

Some Future Challenges for Potato Production

China

Climate Change and Disasters

Due to climate uncertainty across China’s vast territory, environmental stresses and evendisasters such as drought, waterlogging and frost, frequently exert a great impact on potatoproduction. For example, drought occurred in the north in 2009 and in the southwest in2010. Constraints such as drought in the northern region and cold and frost in the centralplains and southern regions should pose major challenges for the future.

Labour Shortage and Low Rate of Mechanization

As China’s urbanization process moves forward, a large portion of rural labourmigrates to cities, drastically reducing the number of rural labourers. This maydisproportionately affect potato production, which is time consuming and labourintensive. Therefore, development of mechanized and simplified cultivation is nec-essary for future potato production. Efforts will be focused on the development of themachinery suitable for the large potato fields in the north and also machinery that isappropriate for small-scale potato production in the southern mountainous regions.

Disease Control

In many regions, potato is a staple crop grown year after year using very limitedpotato cultivars, with very little crop rotation. Such a practice often results inproduction loss due to many of the soil-borne potato diseases mentioned above.Moreover, some of the pathogens develop resistance to chemicals, leading to newchallenges for potato disease control.

Norway

Climate Change and Structural Changes in the Production Will Probably IncreaseQuality Problems

Climate change causing wetter seasons will probably increase problems with diseasessuch as potato late blight. In addition to a possible increase in problems with differentdiseases, mechanical damage of the potato tubers is an important challenge for thepotato business. Mechanical damages are highly associated with inappropriate use ofharvesters. This is often linked to wet conditions during harvest. Soil compaction willalso probably increase in a wetter climate since the size of the tractors and harvestersis steadily increasing related to the increase of the potato area of each farmer. Soilcompaction threatens to reduce yield potential and potato quality.

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Increased Importation of Potatoes Challenges Norwegian Potato Production

Importation of potatoes has increased in the last years, probably due to changes inconsumer preference in favour of small, even-sized potatoes (28–42 mm) for restau-rants and also pre-packed for retail. These tubers normally have better skin qualitythan Norwegian-grown potatoes. The good skin finish of these products also seems tohave resulted in a lower general consumer tolerance for visual defects in potatoes.

Consumption of Potatoes Related to Other Commodities

Norwegian people are eating fewer potatoes; potato consumption reduced by one halfduring the period between 1977 and 2008. It is a challenge to promote potato as animportant staple food in Norway in competition with rice and pasta products. In 2010,potato consumption was challenged by the ‘National Board for Nutrition’, whichsuggested removing potato from the list of ‘healthy’ commodities of vegetable, fruitsand berries. Norwegian potato experts did, however, argue against this by mentioningall the positive nutritional traits of the potato tuber (Molteberg 2011).

References

Holgado R, Magnusson C (2012) Nematodes as a limiting factor in potato production in Scandinavia.Potato Res. doi:10.1007/s11540-012-9209-6

Klingen I, Eklo TS, Spetz CJJ (2012) Begrenset kartlegging av virusoverførende bladlus i potet i Norge i 2011.Bioforsk Report 7(105), 8pp ISBN: 978-82-17-00963-4

Li C, Wang J, Chien DH, Chujoy E, Song B, VanderZaag P (2011) Cooperation-88: a high yielding, multi-purpose, late blight resistant cultivar growing in Southwest China. Am J Potato Res 88(2):190–194

Møllerhagen P (2012) Norsk potetproduksjon 2011. Jord- og plantekultur 2012 (Ed. Strand, E.). BioforskFokus 7(1), 196-199 ISBN: 978-82-17-00870-5

Molteberg EL (2011) Potet – fra « 5 om dagen » til « 5 ganger i uka » ? Jord- og plantekultur 2011 (Ed.Strand, E.). Bioforsk Fokus 6(1), 220-223 ISBN: 978-82-17-00715-9

Nærstad R, Dees MW, Le VH, Holgado R, Hermansen A (2012) Occurrence of skin blemish diseases inNorwegian potato production. Potato Res. doi:10.1007/s11540-012-9221-x

Perminow JIS, Akselsen, ILW, Borowsk, E, Ruden,Ø, Grønås W (2012) Potato ring rot in Norway:Occurrence and control. Potato Res. doi:10.1007/s11540-012-9219-4

Sæthre MG, Hermansen A, Nærstad R (2006). Economic and environmental impacts of the introduction ofWestern flower thrips (Frankliniella occidentalis) and potato late blight (Phytophthora infestans) toNorway. Bioforsk Report 1(64): 35 pp

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