Potato Production Systems Research Articles

Attainable CO2 Emission of Ware Potatoes Under High Yield Conditions in Southern Chile

The objective of the analysis was to calculate the attainable CO2 emissions associated with the production of one ton of potatoes in a high yield environment in southern Chile. Two field experiments were performed. The first field experiment used an optimal sowing date while the second experiment used a late sowing date. In each experiment, treatments were the factorial combination of (i) four N fertilization rates (0, 75, 150 and 250 kg N ha−1) and (ii) four P fertilization rates (0, 150, 300 33 and 450 kg P2O5 ha−1). The Cool Farm Tool – Potato (CFT) was used to calculate the amount of CO2 produced per one ton of potatoes and LINTUL-Potato was used to simulate potential yields. High variations in tuber yields were observed across experiments (90 and 36 t ha−1). The average tuber yield in experiment one (82 t ha−1) was greater than experiment two (51 t ha−1). Tuber yields were not significantly affected by N fertilization in either experiment. In contrast, tuber yield responded (P < 0.01) positively to P fertilization (10–82 %). The gaps between maximum and potential yields simulated in experiments one and two were 4 and 14 %, respectively. In experiment one, the average total CO2 emissions per ton of potatoes were lower than experiment two (41 and 72 kg CO2 eq t−1, respectively). In both experiments the total CO2 emissions were affected (P < 0.01) by both N and P fertilization. We conclude an average CO2 emission of 46 CO2 eq t−1 could be considered an attainable value for potato production systems with high technology intending to improve their carbon footprints in southern Chile.

Economics of organically managed and conventional potato production systems in Atlantic Canada

Khakbazan, M., Henry, R., Haung, J., Mohr, R., Peters, R., Fillmore, S., Rodd, V. and Mills, A. 2015. Economics of organically managed and conventional potato production systems in Atlantic Canada. Can. J. Plant Sci. 95: 161–174. A rotation study was initiated in 2007 in Prince Edward Island (PEI), Canada, to determine the economic effects of converting from conventional potato production to organically managed systems. Seven organically managed rotations, which used various crop combinations to help control pests and soil-borne diseases as well as maintain nutrient levels, were assessed for 2 yr before and 2 yr after organic certification requirements were met in 2009. Each rotation included potato as the main cash crop and at least one other cash crop in a 4-yr rotation and these rotations were compared to a 4-yr conventional rotation. Results indicated that without an organic price premium, significant net revenue losses are expected for most of the seven rotations because of lower yields and high costs. The rotation that included carrots (potato, carrots and mixed peas–oats grain as the cash crops) produced the highest net revenue amongst all rotations studied; however, carrot yield and the net revenue associated with it also showed the greatest variability among all the crops. Organically managed cash crops generated higher net revenues than the conventional potato system only if the average PEI organic price premium was applied. Conventional potato systems produced economic benefits similar to most of the organic rotations when a traditional potato–cereal–green manure rotation was evaluated. The comparison of seven possible rotations provides producers with options if growing organic potatoes.

Seed potato production system in Japan, starting from foundation seed of potato

Potato is one of the staple crops cultivated in upland farming in Japan and is propagated vegetatively by means of tubers. However once infected with diseases, potato yield decreases significantly. And one seed potato can produce approximately only 10 potato tubers. To improve the production system of seed potatoes in Japan, Japanese government established a three-stage propagation system for the production and distribution of healthy and disease-free seed potatoes. The National Center for Seeds and Seedlings (NCSS) has a role for the production of foundation seed potatoes and strictly manages the production in isolated fields that are treated thoroughly to control pests and diseases. Recently though the distribution of foundation seed potatoes is decreasing, the number of varieties of foundation seed potatoes has increased steadily. And new varieties of potato adapted various requirements, including resistance of the golden potato cyst nematode, have been increasing. Therefore, NCSS is introducing a new method of producing minitubers (MnTs) by using hydroponic cultivation greenhouse to increase the efficiency of propagation and to rapidly disseminate these new potato varieties. In this review, we describe a seed potato production system in Japan and the production of foundation seed potatoes as an important role of NCSS.

Sweet Potato Production for Bio-ethanol and Food Related Industry in Indonesia: Challenges for Sustainability

As an underground crop, tuberous root of sweet potato (Ipomoea batatas) is the main economical yield expected from various level of cultivation. Aside rich in carbohydrate, sweet potato root contains vitamin and mineral. The degree of utilization reflects the level of subsistence to commercialization, where the desire or needs can be easily met was defined as prosperity. Supplying continuously the demand of sweet potato for subsistence and commercialization oriented to bio-ethanol and food related industries depend on the sustainable production system. To sustain sweet potato production system, the severe biotic and a-biotic stresses have to be alleviated.

Controls on Nitrate Loading and Implications for BMPs Under Intensive Potato Production Systems in Prince Edward Island, Canada

AbstractPotato production is critical to economy of Prince Edward Island (PEI), but has been linked to increasing groundwater nitrate contamination and anoxic events in estuaries. Given that PEI is entirely groundwater‐dependent for potable water, this has resulted in considerable pressure to find solutions to protect water quality. However, our understanding of the controls on nitrate loading to groundwater, and the consequent potential to mitigate nitrate loading through beneficial management practices (BMPs), is limited. In PEI, flow and nitrate transport in the vadose zone are controlled by the matrix porosity of the till and sandstone, while flow and transport in the saturated zone are controlled by a conductive fracture network with limited storage capacity. Diffusion of nitrate stored in the matrix may introduce a significant time lag between reduced nitrate loading from implementation of BMPs and measureable improvement in groundwater quality. BMPs with potential to mitigate nitrate loading to groundwater through improved nitrogen fertilizer practices in producing potato crops have been identified, but implementation of these practices alone is not sufficient to control nitrate loading due to the economic context of potato production. Additional BMPs for improved potato cropping systems have also been identified; however, reducing the intensity of agricultural production, including the proportion of land in potato production, at the watershed level may be required to meet the drinking water guideline for nitrate in PEI. Given the important role of market forces in determining profitability of crop production, it becomes challenging to modify crop production practices to meet an environmental goal without some additional external incentive or public pressure.

High genotype diversity and lack of isolation by distance in theAlternaria solanipopulations fromChina

A genomic library was used to develop sevenSSRmarkers for studying the population genetics ofAlternaria solani, a pathogenic fungus causing early blight disease of potato and tomato worldwide. Population genetic analysis of 268 isolates ofA. solanisampled from four locations, each representing one of four potato production systems inChina, indicates that theseSSRmarkers are moderately diverse, selectively neutral and possibly unlinked. Population genetic analysis also indicated that genetic variation ofA. solaniinChina is high. About 2/3 of 123 genotypes were detected only once and genotype diversity measured by the standardizedShannon index ranged between 0·82 and 0·92 in the populations. Although clones were detected in multiple populations separated by thousands of kilometres, random association amongSSRloci was found in half of the populations assayed. On average, nearly six copies of genetic material were exchanged among these populations each generation and no isolation by distance was detected. It is hypothesized that the joint effects of cryptic sexual reproduction and human‐mediated gene flow may account for the observed population genetic structure ofA. solaniinChina.

Differentiation of potato ecosystems on the basis of relationships among physical, chemical and biological soil parameters

Boiteau, G., Goyer, C., Rees, H. W. and Zebarth, B. J. 2014. Differentiation of potato ecosystems on the basis of relationships among physical, chemical and biological soil parameters. Can. J. Soil Sci. 94: 463–476. A study of soil physical, chemical and biological properties of five cultivated agro-ecosystems (two conventional potato, two organic potato and one cereal production systems) and two uncultivated agro-ecosystems (pasture and 20-yr abandoned potato field) was carried out at 21 field sites over 3 yr in New Brunswick, Canada. Twenty-four of the initial 42 variables chosen for their significant response to differences among farming systems were used in a principal component analysis to understand their relationships with the agro-ecosystems studied. The chemical, physical and biological soil properties considered contributed to a single dominant factor (PCI) of agricultural soil health representing soil organic matter dynamics. Conventional, uncertified organic and certified organic potato agro-ecosystems were lowest, intermediate and highest, respectively, on the PCI gradient. Conventional potato systems were characterized by high erosion, high soil bulk density, high soil test sulphur and phosphorus and high bacterial counts. Certified organic potato systems formed a separate group with the reference ecosystems (i.e., pasture and abandoned potato field under long-term rejuvenation). This group was characterized by high soil organic carbon, high soil aggregate stability, high soil water-holding capacity and high meso- and macro-fauna counts. The uncertified organic potato production system and organic barley system were characterized by average values, intermediate between conventional and certified organic potato systems. Results confirmed the strong negative impact of intensive cycles of conventional potato production on soil health. The clear separation observed between conventional, uncertified organic and organic potato ecosystems indicates that the positive impact of rotations and other management practices must be sustained over long periods for full rehabilitation of soils previously under intensive potato production. However, results also revealed that fields under organic certified potato production were retaining the properties of undisturbed reference sites such as pastures and abandoned potato fields under long-term rejuvenation.

The potato in Ireland's evolving agrarian landscape and agri-food system

The scale, structure and impacts of food systems in Ireland have changed dramatically over the last several hundred years, predominantly since the mechanisation and intensification of farming began in the late nineteenth century. The transformation of the potato production system, which for the preceding century had dominated the Irish diet, was particularly dramatic. The time from the introduction of the potato c. 1600 to its catastrophic decline in the mid-1800s, represented a period of Irish agriculture distinctly at odds with what came before and after, involving as it did complete dependence on a single crop system. Despite devastating crop losses suffered in the nineteenth century and particularly associated with the Great Famine, the potato remained agriculturally significant in Ireland. From the late 1800s onwards the system underwent a transition towards the highly mechanised, specialised, intensive and market-oriented agri-industrial food systems of today. This new high input-high output system was accompanied by an expansion in environmental impacts extending from local to global scales. This article addresses that transition in the role and impacts of the potato in Ireland, from its introduction to the present day.

Yield Gaps and Ecological Footprints of Potato Production Systems in Chile

In Chile, potatoes are grown in a wide range of ecological zones and levels of technology resulting in wide ranges of crop management and yields. The aim of the present study was to assess yield gaps, resource use efficiencies and foot-printing in different potato cropping zones between 18 and 53° South considering early and late crops, small and large holdings (>10 ha/year) and ware and seed potato crops. Two mathematical tools were used to generate data for comparisons: the light interception and utilization simulator for potato crops (LINTUL-Potato) to calculate potential yields and water need of each system and the Cool Farm Tool – Potato (CFT) to calculate the amount of CO2 associated with the production of 1 ton of potato. Meteorological data for LINTUL-Potato came from official services, and data needed to complete the CFT came from a survey carried out for the 10 sites yielding amounts of inputs and number of operations, potato yields and planting and harvesting dates. The survey yielded 20 cropping systems with an average yield of 31 t ha−1. Yields were related to daily growth rate and not to the length of the growing season. Considerable variation was found in resource-use efficiency and CO2 emission. It was concluded that large farms show a lower land footprint than small farms due to a higher technological level, but while applying more water and fertilizer, they result in higher water and CO2 footprints. Late crops may fetch higher off-season prices but have higher land, water and CO2 footprints. The most suitable potato production systems are the rain-fed summer crops in the South with the lowest footprints. The highest footprints have the irrigated winter crops in the centre of Chile. The subsistence high altitude Andean crop in the utmost North has the highest land footprint but the lowest CO2 emission. The description, analysis and benchmarking of the potato production systems in Chile allow strategies for improving footprints and profitability and yields information about future investments in research, development and production of the crop.

Proceedings from the 2012 PAA Symposium: Potato Phosphorus Management and Utilization for Today and Tomorrow

Sustainable management of phosphorus (P) is a critical component of potato production systems because of a comparatively high plant P requirement, soil reactions that create management challenges, and potential environmental degradation from inappropriate P management. Phosphorus affects potato plant growth in many ways including its effects on plant metabolism, cellular structural components, canopy development, tuber set, nutritional quality, and resistance to some diseases.

Optimizing Phosphorus Fertilizer Management in Potato Production

Management of fertilizer phosphorus (P) is a critical component of potato production systems as potato has a relatively high P requirement and inefficiently uses soil P. Phosphorus promotes rapid canopy development, root cell division, tuber set, and starch synthesis. Adequate P is essential for optimizing tuber yield, solids content, nutritional quality, and resistance to some diseases. Although soil test P is the primary tool for assessing P fertilizer needs, in some areas petiole P analysis has been successfully utilized to guide in-season P applications. Potato has been shown in some studies to respond to fertilizer P at soil test levels considered very high for most other crops (100+ mg kg−1 Bray P1 or Mehlich I or III and 20+ mg kg−1 sodium bicarbonate) especially on medium- to finer-textured soils. Even on high-testing soils, fertilizer P rates for top yields sometimes exceed 150 kg P2O5 ha−1. In addition, many states/provinces continue to recommend half or more of the amount of P in the harvested portion of the crop irrespective of soil test P level. In most situations, few differences are expected among fertilizer P sources; however, high rates of diammonium phosphate (DAP) or urea-phosphate (UAP) should not be band-applied in contact or near the seed piece. Most research determined that fertilizer P was most efficiently used when band-applied at planting (e.g., 5 cm to each side of the seed piece); however, some western USA work on high-pH soils showed increased yields and petiole P levels with preplant broadcast applications. In-season applications with the irrigation water can be successful when the potato roots are sufficiently close to the soil surface; however, most research indicates that P applications are more effective when applied at planting or early in the season. Potato fertilizer phosphorus best management practices include: (1) apply the fertilizer P rate calibrated for local soils; (2) band-apply fertilizer P at least 5 cm from the seed piece, especially on very sandy soils or where DAP or UAP are used; (3) use petiole P tests to determine the need for in-season applications; (4) account for all P sources applied, including animal manures; and (5) utilize the best soil conservation practices to reduce P losses to surface waters.

CARACTERIZACIÓN TECNOLÓGICA PARA LA SOSTENIBILIDAD AMBIENTAL EN PROCESOS PRODUCTIVOS DE PAPA EN ZONAS ALTOANDINAS CAUCANAS

&lt;p&gt;El sistema productivo de la papa en el departamento del Cauca se ha establecido en áreas ambientales estratégicas como los páramos, alterando funciones ecológicas de este sistema como la regulación hídrica, micro-climática y de nutrientes. En el departamento, al ser la papa uno de los renglones más importantes en la economía agraria del Cauca, se viene trabajando para incorporar la gestión ambiental en los procesos de producción agrícola como estrategia de diferenciación y generación de valor agregado; este esfuerzo se ha orientado hacia la caracterización tecnológica con fines de reconversión e incorporación de prácticas sostenibles.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Palabras claves:&lt;/strong&gt; Gestión Ambiental, Papa, Páramo, PML, Tecnologías Rurales.&lt;/p&gt;

Rapeseed rotation, compost and biocontrol amendments reduce soilborne diseases and increase tuber yield in organic and conventional potato production systems

Aims Integrating multiple soil and disease manage- ment practices may improve crop productivity and disease control, but potential interactions and limita- tions need to be determined. Methods Three different potential disease-suppressive management practices, including a Brassica napus (rapeseed) green manure rotation crop, conifer-based compost amendment, and three biological control or- ganisms (Trichoderma virens, Bacillus subtilis, and Rhizoctonia solani hypovirulent isolate Rhs1A1) were evaluated alone and in combination at sites with both organic and conventional management histories for their effects on soilborne diseases and tuber yield. Results Rapeseed rotation reduced all observed soil- borne diseases (stem canker, black scurf, common scab, and silver scurf) by 10 to 52 % in at least one year at both sites. Compost amendment had variable effects on tuber diseases, but consistently increased yield (by 9 to 15 %) at both sites. Biocontrol effects on disease varied, though Rhs1A1 decreased black scurf at the conventional site and T. virens reduced multiple diseases at the organic site in at least one year. Combining rapeseed rotation with compost amend- ment both reduced disease and increased yield, where- as biocontrol additions produced only marginal addi- tive effects. Conclusions Use of these treatments alone, and in combination, can be effective at reducing disease and increasing yield under both conventional and organic production practices.

The influence of organic and conventional fertilisation and crop protection practices, preceding crop, harvest year and weather conditions on yield and quality of potato (Solanum tuberosum) in a long-term management trial

The effects of organic versus conventional crop management practices (fertilisation, crop protection) and preceding crop on potato tuber yield (total, marketable, tuber size grade distribution) and quality (proportion of diseased, green and damaged tubers, tuber macro-nutrient concentrations) parameters were investigated over six years (2004–2009) as part of a long-term factorial field trial in North East England. Inter-year variability (the effects of weather and preceding crop) was observed to have a profound effect on yields and quality parameters, and this variability was greater in organic fertility systems. Total and marketable yields were significantly reduced by the use of both organic crop protection and fertility management. However, the yield gap between organic and conventional fertilisation regimes was greater and more variable than that between crop protection practices. This appears to be attributable mainly to lower and less predictable nitrogen supply in organically fertilised crops. Increased incidence of late blight in organic crop protection systems only occurred when conventional fertilisation was applied. In organically fertilised crops yield was significantly higher following grass/red clover leys than winter wheat, but there was no pre-crop effect in conventionally fertilised crops. The results highlight that nitrogen supply from organic fertilisers rather than inefficient pest and disease control may be the major limiting factor for yields in organic potato production systems.

Use of Biocontrol Organisms and Compost Amendments for Improved Control of Soilborne Diseases and Increased Potato Production

Soilborne potato diseases are persistent problems in potato production and alternative management practices are needed. In this research, biocontrol agents (Bacillus subtilis GB03 and Rhizoctonia solani hypovirulent isolate Rhs1A1) and compost amendments (from different source material), were evaluated alone and in combination, for their potential to reduce soilborne diseases and increase tuber yield over three field seasons in Maine. Both biocontrol organisms reduced multiple soilborne diseases, stem and stolon canker by 20–38 %, black scurf by 30–58 %, and common scab by 10–34 % relative to the nontreated control treatment, and the combination treatment of both biocontrol organisms together provided nominally better control than individual treatments. However, biocontrol treatments had no direct effect on tuber yield. Compost amendments from different sources all increased total and marketable tuber yield substantially (11–37 % and 17–51 %, respectively) relative to nontreated controls. However, except for some reduction of Rhizoctonia canker, compost amendments did not reduce soilborne diseases (black scurf and commons scab) in any year, and resulted in increased levels of common scab in some years (20–45 % increase). The combination compost-biocontrol treatment, although did not perform significantly better than individual component treatments, still provided indications of combined beneficial effects from both component treatments. This research demonstrated the usefulness of these approaches and combinations as additional options for reduction of soilborne diseases and increased tuber yield and can be implemented for enhanced sustainability and productivity in potato production systems.

Economic Potential of Compost Amendment as an Alternative to Irrigation in Maine Potato Production Systems

Potato productivity in the northeastern US has been relatively constant for over 50 years, raising questions about what factors are limiting productivity. Research was initiated in 2004 to identify key constraints to potato productivity by evaluating Status Quo (SQ), Soil Conserving (SC), and Soil Improving (SI) cropping systems under both rainfed and irrigated management, and it was found that addition of compost or irrigation substantially increased yield. In this study, we employed partial budgeting to determine cost differences and their impact on net revenue for these cropping systems. Differences in systems were primarily associated with rotation length, tillage operations, compost and application expenses, and water management practices. When compost (as composted dairy manure) was annually applied at 19 Mg haf-1 and evaluated over the entire 3-year crop rotation cycle, the compost-amended rainfed SI system was more expensive to maintain than the irrigated SC system if compost cost exceeded $3.63 Mg-1. Average marketable yields were used to calculate gross and net revenue for each system. Because average potato yield for the irrigated SQ system (28.4 Mg·ha-1) equaled that in the rainfed SI system (28.3 Mg·ha-1), we were able to compare cost of irrigation versus compost for achieving comparable yield. The compost-amended SI system under rainfed management generated more net revenue from the potato crop than the irrigated SQ system when compost costs were less than $7.42 Mg-1. When compared to the commonly used rainfed SQ system, rainfed SI achieved higher net revenue as long as compost cost was less than $22.95 Mg-1. The rainfed SI system achieved higher net revenue than the irrigated SC system when compost cost was $9.43 Mg-1or less, but generated greater net revenue than the rainfed SC system regardless of compost costs, due to substantially higher yields associated with compost amendment. This investigation demonstrates that compost is a potentially viable substitute to irrigation for potato in the northeastern US; however, such potential is highly dependent on suitable compost sources and application costs.

Effects of different planting systems on yield of potato crop in Kaghan Valley: A mountainous region of Pakistan

Conversion of potato from conventional methods to wide bed planting systems may increase water and nitrogen use efficiency in commercial potato production system by reducing the amount of irrigation water and water applied nitrogen fertilizer bypassing the potato root zone. Potato (Solanum tuberosum L) cv. Desiree was tested against different planting system for yield and yield components at Kaghan, a high mountainous Himalayan region ofPakistan. The experiment was carried out at Himalayan Agricultural Research Station (HARS), Kaghan during the summer season of 2005. The results showed that maximum tuber growth (88.7%), number of stems per plant (3.5), plant expansion (45.5 cm), average number of tubers per plant (10.1) and yield per hectare (12.4 t/ha) were significantly different and higher when potatoes were planted on wide bed and covered with soil from one side. Tallest plants (53.4 cm) were observed when potatoes were sown on the ridges. Maximum number of green potatoes (12.5) and injured potatoes (5.3%) were observed when the tubers were planted following local farmers’ method. Keeping in view the soil type, land slopping, we recommend sowing potatoes on relatively plain wide beds and covering it with soil from one side, for potato cultivation in the area.

Geospatial Evaluations of Potato Production Systems in Maine

Maine consistently ranks in the top ten potato (Solanum tuberosum L.) production areas though yields are substantially lower than the mid- and western USA. Geospatial frameworks help resolve patterns and trends in production environments (at multiple scales) that may enable improvements in adaptive management strategies which enhance yield, increase whole-farm profitability, and foster sustainable land use. Results from geospatial integration of remotely-sensed cropland (2008–2010) and soil datasets for Maine indicate an estimated 61,900 ha in potato production with 62 % and 27 % on prime farmland (PF) and farmland of statewide importance (FSI), respectively. Geospatial analyses of other agri-environmental indicators indicate close to 85 % of these potato production soils are classified as either “potentially highly erodible” (PHEL) or “highly erodible” (HEL). Therefore, at least 52,300 ha require the highest standards in soil conservation practices. Crop rotation patterns for potato, derived from the time-series geo-referenced datasets, help resolve actual cropping practices and facilitated evaluation of the benefits and economic impacts for select alternate crops.

REVIEW ON BROWN ROT (RALSTONIA SOLANACEARUM RACE 3, BIOVAR 2, PHYLOTYPE IIB) EPIDEMIOLOGY AND CONTROL IN THE NETHERLANDS SINCE 1995: A SUCCESS STORY OF INTEGRATED PEST MANAGEMENT

SUMMARY The disease brown rot of potato, caused by the bacterium Ralstonia (Pseudomonas) solanacearum (Rsol), Race 3, biovar 2 (R3b2), was found for the first time in 1992 in a potato field in The Netherlands and caused an outbreak in the warm summer of 1995 that appeared to be connected to use of contaminated irrigation water as in other outbreaks in western Europe at that time. The Dutch Plant Protection Service (PPS) immediately took action and started to test all traded seed for (latent) infections, applied strict control measures upon positive detections, and started an intensive survey of surface water contamination. In later years the control measures and testing procedures for Rsol in different substrates, laid down in an EU Directive, were followed. The PPS also conducted intensive applied research (in cooperation with the University of Wageningen, Plant Research International, and foreign research Institutions, also in the framework of an EU-SMT project on the EU brown rot testing method to unravel the complex epidemiology of the pathogen and to improve its detection and identification. These actions have led over a ca. 15-year period to a drastic reduction, actually a functional eradication (only one single finding in 2009/2010 and 2010/2011), of the disease from the production system. A main factor in the combat was a nation-wide irrigation ban for seed potatoes since 2005. The PPS coordinated two EU-funded projects, where the UK, The Netherlands, Belgium and France assisted Egypt in implementing a brown rot safe potato production system. In this project substantial epidemiological research was conducted. This article wants to be a reflection on the work done and the results obtained by the PPS and has a glance into the future, where it will be indicated that the persisting presence of Rsol in surface water necessitates an enduring alert and actively maintained control and survey system. The main lessons learned are: stay away, if

Abundance of weed hosts as potential sources of onion and potato viruses in western New York

A season-long survey of common weeds was taken near onion and potato fields located within a large vegetable production region in western New York in 2008 and 2009. The objective was to determine the abundance of weed species known as hosts for Iris yellow spot virus (IYSV), a serious pathogen of onion, Potato leafroll virus (PLRV) and Potato virus Y (PVY), which are major pathogens of potato. Ninety-eight weed species were identified, 17 of which are known hosts for IYSV, PLRV and PVY. Common lambsquarters, redroot pigweed, shepherd’s purse, horseweed and dandelion were among the most abundant species known as hosts for these viruses. This information could be useful for studying the role that these weed species have on the epidemiology of the major viruses in onion and potato production systems and for developing future virus management strategies.