Showing papers by "International Potato Center published in 2012"

Introduction of β-carotene-rich orange sweet potato in rural Uganda resulted in increased vitamin A intakes among children and women and improved vitamin A status among children

Abstract: Vitamin A deficiency (VAD) persists in Uganda and the consumption of β-carotene-rich orange sweet potato (OSP) may help to alleviate it. Two large-scale, 2-y intervention programs were implemented among Ugandan farmer households to promote the production and consumption of OSP. The programs differed in their inputs during year 2, with one being more intensive (IP) and the other being reduced (RP). A randomized, controlled effectiveness study compared the impact of the IP and RP with a control on OSP and vitamin A intakes among children aged 6-35 mo (n = 265) and 3-5 y (n = 578), and women (n = 573), and IP compared with control on vitamin A status of 3- to 5-y-old children (n = 891) and women (n = 939) with serum retinol 30 percentage points) and women (>25 percentage points) (P < 0.01), with no differences between the IP and RP groups of children (P = 0.75) or women (P = 0.17). There was a 9.5 percentage point reduction in prevalence of serum retinol <1.05 μmol/L for children with complete data on confounding factors (n = 396; P < 0.05). At follow-up, vitamin A intake from OSP was positively associated with vitamin A status (P < 0.05). Introduction of OSP to Ugandan farming households increased vitamin A intakes among children and women and was associated with improved vitamin A status among children.

A large-scale intervention to introduce orange sweet potato in rural Mozambique increases vitamin A intakes among children and women

Abstract: β-Carotene-rich orange sweet potato (OSP) has been shown to improve vitamin A status of infants and young children in controlled efficacy trials and in a small-scale effectiveness study with intensive exposure to project inputs. However, the potential of this important food crop to reduce the risk of vitamin A deficiency in deficient populations will depend on the ability to distribute OSP vines and promote its household production and consumption on a large scale. In rural Mozambique, we conducted a randomised, controlled effectiveness study of a large-scale intervention to promote household-level OSP production and consumption using integrated agricultural, demand creation/behaviour change and marketing components. The following two intervention models were compared: a low-intensity (1 year) and a high-intensity (nearly 3 years) training model. The primary nutrition outcomes were OSP and vitamin A intakes by children 6-35 months and 3-5·5 years of age, and women. The intervention resulted in significant net increases in OSP intakes (model 1: 46, 48 and 97 g/d) and vitamin A intakes (model 1: 263, 254 and 492 μg retinol activity equivalents/d) among the younger children, older children and women, respectively. OSP accounted for 47-60 % of all sweet potato consumed and, among reference children, provided 80 % of total vitamin A intakes. A similar magnitude of impact was observed for both models, suggesting that group-level trainings in nutrition and agriculture could be limited to the first project year without compromising impact. Introduction of OSP to rural, sweet potato-producing communities in Mozambique is an effective way to improve vitamin A intakes.

Sweetpotato Viruses: 15 Years of Progress on Understanding and Managing Complex Diseases.

Abstract: Sweetpotato is a member of the morning glory family that is thought to have originated in Central or South America but also has a secondary center of diversity in the southwest Pacific islands. It is grown in all tropical and subtropical areas of the world and consistently ranks among the 10 most important food crops worldwide on the basis of dry weight produced, yielding about 130 million metric tons per year on about 9 million hectares. Sweetpotato is an important crop for food security. It has been relied on as a source of calories in many circumstances. Vines and/or storage roots can be used for direct human consumption or animal feed. Growing awareness of health benefits attributed to sweetpotato has stimulated renewed interest in the crop. Orange-fleshed cultivars, a source of vitamin A, were introduced to developing countries with hope that they would replace the white-flesh varieties and help alleviate vitamin A deficiencies. In East Africa, sweetpotato virus disease, which is caused by the synergistic interaction of the whitefly-transmitted crinivirus and the aphid-transmitted potyvirus, can cause losses of 80 to 90% in many high-yielding genotypes. During the past 15 years, as molecular methods have been adopted, much has been learned about the composition of the sweetpotato virus complexes, the effects of virus diseases on production systems, the biology of the virus–plant interaction, and management approaches to sweetpotato virus diseases. This article is intended to summarize what has been learned since earlier reviews, integrate knowledge gleaned from experiences in tropical and temperate production systems, and suggest courses of action to develop sustainable management programs for these diseases.

Phenotyping for drought adaptation in wheat using physiological traits

Abstract: Wheat (Triticum spp) is one of the first domesticated food crops. It represents the first source of calories (after rice) and an important source of proteins in developing countries. As a result of the Green Revolution, wheat yield sharply increased due to the use of improved varieties, irrigation, pesticides, and fertilizers. The rate of increase in world wheat production, however, slowed after 1980, except in China, India, and Pakistan. Being adapted to a wide range of moisture conditions, wheat is grown on more land area worldwide than any other crop, including in drought prone areas. In these marginal rain-fed environments where at least 60 m ha of wheat is grown, amount and distribution of rainfall are the predominant factors influencing yield variability. Intensive work has been carried out in the area of drought adaptation over the last decades. Breeding strategies for drought tolerance improvement include: definition of the target environment, choice and characterization of the testing environment, water stress management and characterization, and use of phenotyping traits with high heritability. The use of integrative traits, facilitated by the development and application of new technologies (thermal imaging, spectral reflectance, stable isotopes) is facilitating high throughput phenotyping and indirect selection, consequently favoring yield improvement in drought prone environments.

Typical patterns of smallholder vulnerability to weather extremes with regard to food security in the Peruvian Altiplano

Abstract: Smallholder livelihoods in the Peruvian Altiplano are frequently threatened by weather extremes, including droughts, frosts and heavy rainfall. Given the persistence of significant undernourishment despite regional development efforts, we propose a cluster approach to evaluate smallholders’ vulnerability to weather extremes with regard to food security. We applied this approach to 268 smallholder households using information from two existing regional assessments and from our own household survey. The cluster analysis revealed four vulnerability patterns that depict typical combinations of household attributes, including their harvest failure risk, agricultural resources, education level and non-agricultural income. We validated the identified vulnerability patterns by demonstrating the correlation between them and an independently reported damage: the purchase of food and fodder resulting from exposure to weather extremes. The vulnerability patterns were then ranked according to the different amounts of purchase. A second validation aspect accounted for independently reported mechanisms explaining smallholders’ sensitivity and adaptive capacity. Based on the similarities among the households, our study contributes to the understanding of vulnerability beyond individual cases. In particular, the validation strengthens the credibility and suitability of our findings for decision-making pertaining to the reduction of vulnerability.

Using Host Resistance to Manage Potato Late Blight with Particular Reference to Developing Countries

Abstract: Potato late blight may be controlled by several approaches including host resistance. Unfortunately, efforts to date to use host resistance have led to limited successes and many failures as pathogen populations have rapidly evolved to overcome resistance or durably resistant varieties have had limited adoption. Several problems hinder diffusion of resistant cultivars, including a rapidly evolving pathogen population, market preferences, association of resistance with late maturation, and methodological issues such as inaccurate phenotyping and insufficient communication among researchers, the latter particularly in developing countries. New technologies and approaches that improve the identification and adoption of resistant varieties are discussed, including biotechnology, enhanced conventional breeding, pathogen monitoring, improved phenotyping, and better research collaboration.

Improving Seed Health and Seed Performance by Positive Selection in Three Kenyan Potato Varieties

Abstract: Selecting seed potatoes from healthy-looking mother plants (positive selection) was compared with common Kenyan farmer practice of selection from the harvested bulk of potatoes (farmer selection) in 23 farmer-managed trials. Positive selection assured lower incidences of PLRV (39%), PVY (35%) and PVX (35%). Positive selection out-yielded farmer selection irrespective of the agro-ecology, crop management, soil fertility, variety and quality of the starter seed, with an overall average of 30%. Regression analysis showed a relation between lower virus incidence and higher yield for the varieties. The paper discusses the consequences for seed system management in African countries. Furthermore possible additional effects of positive selection are discussed and further research is suggested. The paper concludes that positive selection can benefit all smallholder potato producers who at some stage select seed potatoes from their own fields, and should thus be incorporated routinely in agricultural extension efforts.

Large-scale evaluation of potato improved varieties, genetic stocks and landraces for drought tolerance.

Abstract: Potato production worldwide is strongly affected by water stress, either because of insufficient rainfall or due to inadequate irrigation. Improving drought tolerance is consequently becoming a priority for potato breeders, particularly in the perspective of climate change. In the present study, a set of 918 accessions from CIP world potato collection was evaluated under field conditions with full irrigation and deficit irrigation, on the desertic coast of Peru. The set included improved varieties, genetic stocks and landraces. The subset of landraces comprised accessions from the species Solanum ajanhuiri Juz. & Bukasov, Solanum curtilobum Juz. & Bukasov, Solanum juzepczukii Bukasov and Solanum tuberosum L. S. tuberosum L. included non Andean accessions of the ssp. Chilotanum as well as accessions belonging to the Andean cultivar groups Andigenum, Chaucha, Goniocalyx, Phureja and Stenotomum. Under both drought and irrigated treatments, significant differences were found for tuber yield, tuber number and tuber weight among subsets, cultivar groups and accessions. On average, improved varieties and advanced bred lines yielded more under both deficit and well-irrigated conditions than did landraces, while variation for drought susceptibility was greater in landraces and genetic stocks than in improved varieties. Within the subset of landraces, the species Solanum juzepczukii Bukasov exhibited the lowest average values and highest variation for drought susceptibility. A high proportion of accessions combining low drought susceptibility and high irrigated yield were found in Andean landraces, and particularly in the species Solanum curtilobum Juz. & Bukasov in the S. tuberosum L. cultivar groups Stenotomum, Andigenum and Chaucha. The differences observed among species and cultivar groups were not directly related to their eco-geographic distribution. The polyploid species and cultivars groups appeared more drought tolerant than the diploid ones. The study evidenced the interest of Andean landraces as potential sources of drought tolerance in potato breeding programs.

Precipitation Characteristics of the South American Monsoon System Derived from Multiple Datasets

Abstract: TheSouthAmericanmonsoon system(SAMS) isthemostimportant climaticfeature in South America and is characterized by pronounced seasonality in precipitation during the austral summer. This study compares several statistical properties of daily gridded precipitation from different data (1998‐2008): 1) Physical Sciences Division (PSD), Earth System Research Laboratory [1.08 and 2.58 latitude (lat)/longitude (lon)]; 2) Global Precipitation Climatology Project (GPCP; 18 lat/lon); 3) Climate Prediction Center (CPC) unified gauge (CPC-uni) (0.58 lat/lon); 4) NCEP Climate Forecast System Reanalysis (CFSR) (0.58 lat/lon); 5) NASA Modern-Era Retrospective Analysis for Research and Applications (MERRA) reanalysis (0.58 lat/0.38 lon); and 6) Tropical Rainfall Measuring Mission (TRMM) 3B42 V6 data (0.258 lat/lon). The same statistical analyses are applied to data in 1) a common 2.58 lat/lon grid and 2) in the original resolutions of the datasets. Alldatasetsconsistentlyrepresentthelarge-scalepatternsoftheSAMS.Theonset,demise,anddurationof SAMS are consistent among PSD, GPCP, CPC-uni, and TRMM datasets, whereas CFSR and MERRA seem to have problems in capturingthe correct timing of SAMS. Spectral analyses show that intraseasonal variance is somewhat similar in the six datasets. Moreover, differences in spatial patterns of mean precipitation are small among PSD, GPCP, CPC-uni, and TRMM data, while some discrepancies are found in CFSR and MERRA relative to the other datasets. Fitting of gamma frequency distributions to daily precipitation shows differences in the parameters that characterize the shape, scale, and tails of the frequency distributions. This suggests that significant uncertainties exist in the characterization of extreme precipitation, an issue that is highly important in the context of climate variability and change in South America.

Single copy nuclear gene analysis of polyploidy in wild potatoes ( Solanum section Petota )

Abstract: Recent genomic studies have drastically altered our knowledge of polyploid evolution. Wild potatoes (Solanum section Petota) are a highly diverse and economically important group of about 100 species widely distributed throughout the Americas. Thirty-six percent of the species in section Petota are polyploid or with diploid and polyploid cytotypes. However, the group is poorly understood at the genomic level and the series is ideal to study polyploid evolution. Two separate studies using the nuclear orthologs GBSSI and nitrate reductase confirmed prior hypotheses of polyploid origins in potato and have shown new origins not proposed before. These studies have been limited, however, by the use of few accessions per polyploid species and by low taxonomic resolution, providing clade-specific, but not species-specific origins within clades. The purpose of the present study is to use six nuclear orthologs, within 54 accessions of 11 polyploid species, 34 accessions of 29 diploid species of section Petota representing their putative progenitors, and two outgroups, to see if phenomena typical of other polyploid groups occur within wild potatoes, to include multiple origins, loss of alleles, or gain of new alleles. Our results increase resolution within clades, giving better ideas of diploid progenitors, and show unexpected complexity of allele sharing within clades. While some species have little diversity among accessions and concur with the GBSSI and nitrate reductase results, such as S. agrimonifolium, S. colombianum, S. hjertingii, and S. moscopanum, the results give much better resolution of species-specific progenitors. Seven other species, however, show variant patterns of allele distributions suggesting multiple origins and allele loss. Complex three-genome origins are supported for S. hougasii, and S. schenckii, and one of the ten accessions of S. stoloniferum. A very unexpected shared presence of alleles occurs within one clade of S. verrucosum from Central America, and S. berthaultii from South America in six polyploid species S. demissum, S. hjertingii, S. hougasii, S. iopetalum, S. schenckii, and S. stoloniferum. Our results document considerable genomic complexity of some wild potato polyploids. These can be explained by multiple hybrid origins and allele losses that provide a clear biological explanation for the taxonomic complexity in wild potato polyploids. These results are of theoretical and practical benefit to potato breeders, and add to a growing body of evidence showing considerable complexity in polyploid plants in general.

Use of Phosphonate to Manage Foliar Potato Late Blight in Developing Countries.

Abstract: Twenty phosphonate products found in the agrochemical market in Ecuador and Peru were evaluated in bioassays for the control of foliar potato late blight, caused by Phytophthora infestans. Eight phosphonate products were evaluated in 16 field experiments done in Peru, Ecuador, Kenya, and Nepal. A meta-analysis across locations involving 71 combinations of potato genotype by site and year demonstrated a significant relationship between phosphonate application rate and efficacy for controlling late blight on potato foliage. The meta-analysis revealed that phosphonate rates of approximately 2.5 g a.i./liter provided efficacy similar to that of the conventional contact fungicides mancozeb and chlorothalonil used at similar rates. At rates higher than 2.5 g a.i./liter, the efficacy of phosphonate was superior to the contact fungicides. Overall, late blight control by phosphonate appeared relatively stable in field experiments across locations. An analysis of field experiments and 64 combinations of potato genotype by site and year showed no correlation between the susceptibility level of potato genotypes and efficacy of phosphonates. The cost of both phosphonate compounds and contact fungicides varied greatly among the countries of the field study; however, in Kenya, control with phosphonate was clearly less expensive than with mancozeb.

Conditional QTL underlying resistance to late blight in a diploid potato population.

Abstract: A large number of quantitative trait loci (QTL) for resistance to late blight of potato have been reported with a “conventional” method in which each phenotypic trait reflects the cumulative genetic effects for the duration of the disease process. However, as genes controlling response to disease may have unique contributions with specific temporal features, it is important to consider the phenotype as dynamic. Here, using the net genetic effects evidenced at consecutive time points during disease development, we report the first conditional mapping of QTL underlying late blight resistance in potato under five environments in Peru. Six conditional QTL were mapped, one each on chromosome 2, 7 and 12 and three on chromosome 9. These QTL represent distinct contributions to the phenotypic variation at different stages of disease development. By comparison, when conventional mapping was conducted, only one QTL was detected on chromosome 9. This QTL was the same as one of the conditional QTL. The results imply that conditional QTL reflect genes that function at particular stages during the host–pathogen interaction. The dynamics revealed by conditional QTL mapping could contribute to the understanding of the molecular mechanism of late blight resistance and these QTL could be used to target genes for marker development or manipulation to improve resistance.

Drought Impacts Mineral Contents in Andean Potato Cultivars

Abstract: Mineral micro- and macronutrients in tubers of 21 Andean potato cultivars were investigated in a field trial under control and drought conditions. Mineral concentrations in potato tubers were highly variable between genotypes; some were significantly and positively correlated with each other, the most noteworthy associations being Na-Ca, Mn-Mg and Zn-Fe, in both control and drought-stressed plants. Overall, increasing yields are related to decreased concentrations of some nutrients, albeit some higher-yielding cultivars also displayed important concentrations of nutrients in their tubers. The most striking result was the increase in the concentration of the majority of the analysed cations in a large number of cultivars in response to water depletion; some of them, such as K, may be related to water homeostasis and/or to sucrose loading and unloading in phloem sap. Tuber mineral concentrations were not related to drought tolerance in terms of tuber productivity. Interestingly, yield loss under drought was not correlated with yield potential under control conditions. Identification of cultivars such as 703264 and 701106 able to maintain good yield stability in association with high mineral contents under water deprivation is of particular interest, especially in view of the importance of potato as a staple crop and the expansion of its cultivation to non-optimal cultivation areas in the context of changing climatic conditions.

Developing Integrated Pest Management for Potato: Experiences and Lessons from Two Distinct Potato Production Systems of Peru

Abstract: Potato (Solanum tuberosum L.) is cultivated in diverse agroecosystems, which may harbor different insect pests; accordingly, potato farmers need to have appropriate site-specific pest control solutions. We developed Integrated Pest Management (IPM) strategies for potato production systems of the high Andes and the coast of Peru. This required considering all economically important pests and developing technological innovations to replace farmers’ pesticide applications with equal efficacy. Examples are the use of plastic barriers that effectively prevent infestations of migrating Andean potato weevils (Premnotrypes spp.), the use of attract-and-kill for managing potato tuber moths [Phthorimaea operculella (Zeller), Symmetrischema tangolias (Gyen.)], or the rational use of insecticides to control flea beetles (Epitrix spp.) in the Andean highlands, or the leafminer fly [Liriomyza huidobrensis (Blanchard)] and the bud midge [Prodiplosis longifila (Gagne)] in the coastal lowlands. Moreover, the resilience of potato agroecosystems can be increased through augmentation strategies for natural enemies at the field level and inoculative biological control to recuperate species lost through the intensive use of pesticides. Potato IPM showed clear economic and ecological benefits at pilot sites. Strong public-private partnerships will be crucial for technology delivery, and well-trained field advisors are required to support the specific needs of farmers to adopt IPM.

From Mao to McDonald’s: Emerging Markets for Potatoes and Potato Products in China 1961–2007

Abstract: China is not only the world’s largest producer of potatoes, but also its largest consumer. This article uses a value chain framework, FAO times-series data and a review of the literature to estimate and then interpret growth rates for the different uses of potatoes in China over the last five decades. It singles out changes in government policy, production, per capita incomes, and consumer tastes and preferences to explain the rise in consumption of potatoes as food and the decline in their use as feed. The paper also notes the negligible importance of imports as a percentage of the total volume of potatoes consumed and the emerging influence of various private sector initiatives before reassessing past projections of future utilization levels. It concludes by highlighting opportunities for industry and identifying some key topics for future research.

Complete genome sequence of a potyvirus infecting yam beans (Pachyrhizus spp.) in Peru

Abstract: In 2010, yam beans in a field trial in Peru showed viral disease symptoms. Graft-transmission and positive ELISA results using potyvirus-specific antibodies suggested that the symptoms could be the result of a potyviral infection. Small interfering RNA (siRNA) were extracted from one of the samples and sent for high-throughput sequencing. The full genome of a new potyvirus could be assembled from the resulting siRNA sequences, and it was sufficiently different from other sequences to be considered a member of a new species, which we have designated Yam bean mosaic virus (YBMV). Sequence similarity suggests that YBMV has also been detected in yam beans in Indonesia.

Limits to Growth or Growth to the Limits? Trends and Projections for Potatoes in China and Their Implications for Industry

Abstract: While output for potatoes in China averaged nearly 73 million metric tonnes in 2008–2010, the trends for production, area, and yield have been far more volatile than suggested in earlier studies. A new set of estimated growth rates for potato production in China during the last five decades based on FAO times series data found that periods of rapid expansion were then followed by ones of stagnation and decline. Although increases in potato output have been impressive, China’s share of both regional and global production has declined in recent years as a result. This paper analyses these and other dimensions to the evolution of potato production in China during the last half century by synthesizing previous research before reassessing alternative future projections, highlighting opportunities for industry, and identifying some key topics for future research.

The Enigma of Solanum maglia in the Origin of the Chilean Cultivated Potato, Solanum tuberosum Chilotanum Group1

Abstract: The Enigma of Solanum maglia in the Origin of the Chilean Cultivated Potato, Solanum tuberosum Chilotanum Group. Landrace potato cultivars occur in two broad geographic regions: the high Andes from western Venezuela south to northern Argentina (Solanum tuberosum Andigenum Group, “Andigenum”), and lowland south-central Chile (S. tuberosum Chilotanum Group, “Chilotanum”), with a coastal desert and 560 km between southernmost populations of Andigenum and Chilotanum. Unlike Andigenum landraces, Chilotanum landraces are adapted to long days and carry a 241 base pair plastid DNA deletion. However, Andigenum and Chilotanum landraces are morphologically similar. We investigated a hypothesis that Chilotanum landraces arose from Solanum maglia, a rare tuber-bearing species found in Chile and Argentina. This hypothesis was formulated first based on morphological analyses of starch grains of extant and preserved (12,500 years before present) S. maglia, and on putative sympatry of extant S. maglia and Chilotanum landraces. Our new starch grain analyses fail to support this hypothesis; we could find no evidence of current sympatric distributions, and S. maglia lacks the 241-bp plastid deletion. However, microsatellite data group all accessions of S. maglia exclusively with Chilotanum, which is supported by our previous observation at the single locus of the waxy gene. These results could be interpreted in various ways, but all explanations have problems. One explanation is that S. maglia is a progenitor of Chilotanum. However, the plastid deletion in Chilotanum but not S. maglia cannot be easily explained. Another explanation is that Chilotanum was formed by hybridization between S. maglia and pre-Chilotanum, but this conflicts with prior cladistic analyses. These new data shed light on aspects of this question and highlight various evolutionary scenarios, but the origin of Chilotanum and the involvement of S. maglia in its origin remain an enigma.

First report of Sweet potato leaf curl virus infecting sweet potato in Argentina

Abstract: We report the complete nucleotide sequence of a begomovirus infecting sweet potato in the Northeastern region of Argentina. Sequence comparisons indicated that the isolate under study has the highest nucleotide sequence identity (93.6 %) with Sweet potato leaf curl virus Puerto Rico. According to the current taxonomic criteria for bego- movirus classification the Argentinean isolate would corre- spond to a new strain of Sweet potato leaf curl virus.

Detection of bacterial wilt infection caused by Ralstonia solanacearum in potato ( Solanum tuberosum L.) through multifractal analysis applied to remotely sensed data

Abstract: Potato bacterial wilt, caused by the bacterium Ralstonia solanacearum race 3 biovar 2 (R3bv2), affects potato production in several regions in the world. The disease becomes visually detectable when extensive damage to the crop has already occurred. Two greenhouse experiments were conducted to test the capability of a remote sensing diagnostic method supported by multispectral and multifractal analyses of the light reflectance signal, to detect physiological and morphological changes in plants caused by the infection. The analysis was carried out using the Wavelet Transform Modulus Maxima (WTMM) combined with the Multifractal (MF) analysis to assess the variability of high-resolution temporal and spatial signals and the conservative properties of the processes across temporal and spatial scales. The multispectral signal, enhanced by multifractal analysis, detected both symptomatic and latently infected plants, matching the results of ELISA laboratory assessment in 100 and 82%, respectively. Although the multispectral method provided no earlier detection than the visual assessment on symptomatic plants, the former was able to detect asymptomatic latent infection, showing a great potential as a monitoring tool for the control of bacterial wilt in potato crops. Applied to precision agriculture, this capability of the remote sensing diagnostic methodology would provide a more efficient control of the disease through an early and full spatial assessment of the health status of the crop and the prevention of spreading the disease.

Land use and climate change adaptation strategies in Kenya

Abstract: Climate variability and change mitigation and adaptation policies need to prioritize land users needs at local level because it is at this level that impact is felt most. In order to address the challenge of socio-economic and unique regional geographical setting, a customized methodological framework was developed for application in assessment of climate change vulnerability perception and adaptation options around the East African region. Indicators of climate change and variability most appropriate for the region were derived from focused discussions involving key informants in various sectors of the economy drawn from three East African countries. Using these indicators, a structured questionnaire was developed from which surveys and interviews were done on selected sample of target population of farming communities in the Mt. Kenya region. The key highlights of the questionnaire were vulnerability and adaptation. Data obtained from respondents was standardized and subjected to multivariate and ANOVA analysis. Based on principle component analysis (PCA), two main vulnerability categories were identified namely the social and the bio-physical vulnerability indicators. Analysis of variance using Kruskal-Wallis test showed significant statistical variation (P ≤ 0.05) in the perceived vulnerability across the spatial distribution of the 198 respondents. Three insights were distinguished and were discernible by agro-ecological zones. Different vulnerability profiles and adaptive capacity profiles were generated demonstrating the need for prioritizing adaptation and mitigation efforts at local level. There was a high correlation between the bio-physical and social factor/livelihood variables that were assessed.

Explaining Andean Potato Weevils in Relation to Local and Landscape Features: A Facilitated Ecoinformatics Approach

Abstract: Background Pest impact on an agricultural field is jointly influenced by local and landscape features. Rarely, however, are these features studied together. The present study applies a “facilitated ecoinformatics” approach to jointly screen many local and landscape features of suspected importance to Andean potato weevils (Premnotrypes spp.), the most serious pests of potatoes in the high Andes. Methodology/Principal Findings We generated a comprehensive list of predictors of weevil damage, including both local and landscape features deemed important by farmers and researchers. To test their importance, we assembled an observational dataset measuring these features across 138 randomly-selected potato fields in Huancavelica, Peru. Data for local features were generated primarily by participating farmers who were trained to maintain records of their management operations. An information theoretic approach to modeling the data resulted in 131,071 models, the best of which explained 40.2–46.4% of the observed variance in infestations. The best model considering both local and landscape features strongly outperformed the best models considering them in isolation. Multi-model inferences confirmed many, but not all of the expected patterns, and suggested gaps in local knowledge for Andean potato weevils. The most important predictors were the field's perimeter-to-area ratio, the number of nearby potato storage units, the amount of potatoes planted in close proximity to the field, and the number of insecticide treatments made early in the season. Conclusions/Significance Results underscored the need to refine the timing of insecticide applications and to explore adjustments in potato hilling as potential control tactics for Andean weevils. We believe our study illustrates the potential of ecoinformatics research to help streamline IPM learning in agricultural learning collaboratives.

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

Abstract: Potato is the third most important food crop in the world after rice and wheat in terms of human consumption. More than a billion people worldwide eat potato, and global total crop production exceeds 300 million metric tons (http://www.cipotato.org/potato). Potato is also an important crop in Norway and China. Norway has approximately five million inhabitants while China has 1.4 billion inhabitants. Potato production in the two countries is of similar importance relative to their respective population sizes. China has the highest production of potato in the world according to figures from 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, which is 21% of the total global output of this crop. Due to the adaptability and tolerance of the potato plant to drought, cold climate and infertile soils, it can grow in most regions in China and is widely grown in almost all provinces. In 2010, potato acreage was over 333,000 ha in the following provinces, autonomous regions and municipalities: Inner Mongolia, Guizhou, Gansu, Sichuan, Potato Research (2012) 55:197–203 DOI 10.1007/s11540-012-9224-7

Tackling Challenges to Farmers’ Health and Agro-Ecosystem Sustainability in Highland Ecuador

Abstract: Over the last half century, agricultural “modernization” has transformed ­smallholder potato and horticultural production systems on the once fertile slopes of the Ecuadorian Andes (Sherwood 2009). Striving to maintain outputs, farms and fields dotted across the mountainous landscape have increasingly used external inputs (machinery, contract labour, fertilizers, and pesticides).

How did Flowering Plants Learn to Avoid Blind Date Mistakes

Abstract: Self-incompatibility (SI) is a common form of genetically-controlled mate-selection that prevents mating between closely related plants of the same species SI occurs in about half of all flowering plant species It has been studied extensively in the Papaveraceae (poppy), Brassicaceae (Arabidopsis, cabbage etc), Solanaceae (potato, tomato etc), Plantaginaceae (snapdragon) and Rosaceae (apple, cherry and peach etc) The self-recognition inherent in self-incompatibility has similarities with animal and plant immunity systems giving rise to speculation that the systems are related Both systems display balancing selection, ‘self/nonself’ recognition, high polymorphism, high specificity and there are also some similarities in the rejection mechanisms deployed in the two systems Whether these systems have diverged from a common predecessor is discussed, however similarities may be driven more by biological problems and the available molecular machinery to solve them than by an evolutionary relationship

Life Histories and Fitness of Two Tuber Moth Species Feeding on Native Andean Potatoes

Abstract: In the inter-Andean valleys of central Peru, two species of tuber moth, Phthorimaea operculella (Zeller) and Symmetrischema tangolias (Gyen), often occur simultaneously in stored potatoes. Traditional farming communities in the region produce a variety of native potatoes for local consumption. These include Solanum tuberosum subsp. andigena, the presumed predecessor of commercial potatoes, S. tuberosum subsp. tuberosum. In this study, we examined resistance against P. operculella in ten native Peruvian potato varieties (Casa blanca, Chispiadita, Madre de vaca, Mamaco negro, Misha, Chorisa, Mamaco rosado, Occa papa, Vacapa jayllo, and Yana tornasol). We also compared resistance in the first five of these varieties against S. tangolias. Varieties with pigmented periderms showed moderate resistance (30–40% against P. operculella in Mamaco negro, Mamaco rosado, and Yana tornasol and 55% against S. tangolias in Mamaco negro). All the other varieties were susceptible to both moth species. Small tubers tended to be the most resistant to the attack by both moths; however, this was not related to the availability of food for developing larvae, since pupal weight and development time were unaffected by the size of tubers. Similar responses by the two moths to native potatoes indicate that tuber resistance could be used to control the complex of tuber moths that damage potatoes in the Andes. We suggest that native potatoes, which are often easily introgressed with commercial potatoes, are a potential source of resistance against tuber moths.