Analysis of competitive and comparative advantages of potato production in Indonesia.

Fundamental issues in sustainable development of competitive potato production in Indonesia are production and distribution inefficiencies. This study aims to examine the potato production competitiveness through competitive and comparative analyses as well as evaluating the impacts of government policy on potato production. This study employs Policy Analysis Matrix (PAM) to analyse the cross-section data collected from six regencies in Indonesia. Potato production in Indonesia was profitable privately and socially. The highest value of competitive advantage was indicated by PCR value in the dry season in Wonosobo Regency, Central Java Province. The lowest values were found in Bandung Regency. Highest comparative advantage was revealed in Tanah Karo Regency, North Sumatra Province, during the rainy season. Highest comparative advantage was found in Bandung Regency, West Java Province, in the dry season. However, the social profit was lower than the private profit indicating the potato farmers dealt with disincentives due to imperfect market. It implies that increasing domestic potato production will be more profitable rather than import. The policy makers need to evaluate the recent policies on input and output markets as well as the supply chain of potato to cope with imperfect markets in order to increase farmers' income.

Quantifying risk factors associated with light-induced potato tuber greening in retail stores.

Light conditions in retail stores may contribute to potato greening. In this study, we aimed to develop a potato tuber greening risk rating model for retail stores based on light quality and intensity parameters. This was achieved by firstly exposing three potato varieties (Nicola, Maranca and Kennebec) to seven specific light wavelengths (370, 420, 450, 530, 630, 660 and 735 nm) to determine the tuber greening propensity. Detailed light quality and intensity measurements from 25 retail stores were then combined with the greening propensity data to develop a tuber greening risk rating model. Our study showed that maximum greening occurred under blue light (450 nm), while 53%, 65% and 75% less occurred under green (530 nm), red (660 nm) and orange (630 nm) light, respectively. Greening risk, which varied between stores, was found to be related to light intensity level, and partially explained potato stock loss in stores. Our results from this study suggested that other in-store management practices, including lighting duration, average potato turnover, and light protection during non-retail periods, likely influence tuber greening risk.

Agronomic and Economic Interactions between Sidedressed Nitrogen and Potassium Fertilizations on Atlantic Potato

Abstract Nitrogen (N) and potassium (K) in potato crop planting synergistically increase tuber yield, but there are no studies on this interaction in sidedressing. In two experiments with 'Atlantic' potato combinations of four N rates (0, 50, 100, and 150 kg ha-1) with four K2O rates (0, 100, 200, and 300 kg ha-1) were applied in sidedressing in a 4×4 factorial scheme with three replications in a completely randomized design. Adjacent commercial fields were sampled to economic comparisons with experimental results. Significant interaction between N and K sidedressing rates with tuber yields increase also was confirmed and classified as Liebig-synergism. Compared to the isolated N and K applications in sidedressing, joint N and K fertilizations, respectively, increases by 11% and 48% marketable tuber yields in the summer-fall experiment, and 12% and 7% in the spring experiment. Joint N and K applications as sidedressing was more profitable than planting fertilization, mainly at higher N and K rates. The response of specific gravity of 'Atlantic' potato tubers to the N and K sidedressing rates was mediated by interactions between edaphoclimatic conditions and inputs of N and K. The combined application of N and K sidedressing rates increased specific gravity in the summer-fall experiment, but had a negative effect in the spring experiment. Therefore, our results provide strong evidence that the fertilization management for potato crop in Brazil can be modified by applying higher amounts of N and K in sidedressing to match nutritional needs of the crop.

The Impact of Body Image on the WTP Values for Reduced-Fat and Low-Salt Content Potato Chips among Obese and Non-Obese Consumers.

The aim of this study is to assess the influence of body image on consumers' willingness to pay (WTP) for potato chips carrying nutritional claims among obese and non-obese people. About 309 non-clinical individuals participated in a Real Choice Experiment. They were recruited by a company and grouped in: (i) non-obese with good body image; (ii) non-obese with body image dissatisfaction; (iii) obese with good body image; (iv) obese with body image dissatisfaction. Results indicate differences in consumers' willingness to pay among consumer groups. Body image dissatisfaction of normal people did not influence the WTP for healthier chips. Obese people with body image dissatisfaction were willing to pay more for healthier chips (i.e., low-salt content potato chips) than normal ones with body image dissatisfaction. Examining the role of knowledge in the light of how this could impact on body image is relevant to improve the health status of individuals and their diet. Knowledge about nutrition could improve the body image of obese people.

A GC-MS-based metabolomics study on the tubers of commercial potato cultivars upon storage.

Using gas chromatography-mass spectrometry (GC-MS) as a system for the detection of amino acids, organic acids, sugars, sugar alcohols, and fatty acids, we characterised six commercial potato cultivars (Hópehely, Katica, Lorett, Somogyi kifli, Vénusz Gold, and White Lady) with different pedigrees, starch contents, cooking types, and dormancy periods, in five developmental stages from harvest to sprouting. The tubers were stored at 20-22°C in the dark. The metabolite data were subjected to principal component analysis. No correlation between metabolite contents of freshly harvested tubers and starch content or cooking type of the cultivars was detected. The storage decreased the fructose and sucrose and increased the proline concentrations of tubers. Irrespective of the length of dormancy a substantial difference in metabolite composition at each time point upon storage was detected in each cultivar except Somogyi kifli, the only cultivar amongst those tested with a pure Solanum tuberosum origin and A cooking type.

Vegetable cost metrics show that potatoes and beans provide most nutrients per penny.

Vegetables are important sources of dietary fiber, vitamins and minerals in the diets of children. The United States Department of Agriculture (USDA) National School Lunch Program has new requirements for weekly servings of vegetable subgroups as well as beans and peas. This study estimated the cost impact of meeting the USDA requirements using 2008 national prices for 98 vegetables, fresh, frozen, and canned. Food costs were calculated per 100 grams, per 100 calories, and per edible cup. Rank 6 score, a nutrient density measure was based on six nutrients: dietary fiber; potassium; magnesium; and vitamins A, C, and K. Individual nutrient costs were measured as the monetary cost of 10% daily value of each nutrient per cup equivalent. ANOVAs with post hoc tests showed that beans and starchy vegetables, including white potatoes, were cheaper per 100 calories than were dark-green and deep-yellow vegetables. Fresh, frozen, and canned vegetables had similar nutrient profiles and provided comparable nutritional value. However, less than half (n = 46) of the 98 vegetables listed by the USDA were were consumed >5 times by children and adolescents in the 2003-4 National Health and Nutrition Examination Survey database. For the more frequently consumed vegetables, potatoes and beans were the lowest-cost sources of potassium and fiber. These new metrics of affordable nutrition can help food service and health professionals identify those vegetable subgroups in the school lunch that provide the best nutritional value per penny.

New metrics of affordable nutrition: which vegetables provide most nutrients for least cost?

Measuring food prices per gram, rather than per calorie, is one way to make healthful vegetables appear less expensive. However, a better measure of affordability would take the nutrient content of vegetables into account. This study, based on analyses of US Department of Agriculture datasets, aimed to identify which vegetables, including juices and soups, provided the most nutrients per unit cost. Nutrient density was measured using the Nutrient Rich Foods (NRF) index, based on nine nutrients to encourage: protein; fiber; vitamins A, C, and E; calcium; iron; magnesium; and potassium; and on three nutrients to limit: saturated fat, added sugar, and sodium. Food cost in dollars was calculated per 100 g, per 100 kcal, per serving, and per nutrient content. One-way analyses of variance with post hoc tests were used to determine statistical significance. Results showed that tomato juices and tomato soups, dark green leafy and nonleafy vegetables, and deep yellow vegetables, including sweet potatoes, had the highest NRF scores overall. Highest NRF scores per dollar were obtained for sweet potatoes, white potatoes, tomato juices and tomato soups, carrots, and broccoli. Tomato sauces, raw tomatoes, and potato chips were eaten more frequently than were many other vegetables that were both more affordable and more nutrient-rich. These new measures of affordable nutrition can help foodservice and health professionals identify those vegetables that provide the highest nutrient density per unit cost. Processed vegetables, including soups and juices, can contribute to the quality and the affordability of the diet.

Retrospective view of North American potato (Solanum tuberosum L.) breeding in the 20th and 21st centuries.

Cultivated potato (Solanum tuberosum L.), a vegetatively propagated autotetraploid, has been bred for distinct market classes, including fresh market, pigmented, and processing varieties. Breeding efforts have relied on phenotypic selection of populations developed from intra- and intermarket class crosses and introgressions of wild and cultivated Solanum relatives. To retrospectively explore the effects of potato breeding at the genome level, we used 8303 single-nucleotide polymorphism markers to genotype a 250-line diversity panel composed of wild species, genetic stocks, and cultivated potato lines with release dates ranging from 1857 to 2011. Population structure analysis revealed four subpopulations within the panel, with cultivated potato lines grouping together and separate from wild species and genetic stocks. With pairwise kinship estimates clear separation between potato market classes was observed. Modern breeding efforts have scarcely changed the percentage of heterozygous loci or the frequency of homozygous, single-dose, and duplex loci on a genome level, despite concerted efforts by breeders. In contrast, clear selection in less than 50 years of breeding was observed for alleles in biosynthetic pathways important for market class-specific traits such as pigmentation and carbohydrate composition. Although improvement and diversification for distinct market classes was observed through whole-genome analysis of historic and current potato lines, an increased rate of gain from selection will be required to meet growing global food demands and challenges due to climate change. Understanding the genetic basis of diversification and trait improvement will allow for more rapid genome-guided improvement of potato in future breeding efforts.

Determination of acrylamide in local and commercial cultivar of potatoes from biological farm.

This paper reports the results of a preliminary study on the characterization of parameters influencing formation of acrylamide in fried potatoes, from biological cultivation. The formation of acrylamide was investigated in relation to frying in biological extra virgin olive oil and commercial seed oil. Three different cultivars (Rossa di Colfiorito, Quarantina bianca genovese and Kennebec) were chosen. Asparagine, glucose, fructose and sucrose concentrations were determined in potato slice before frying, while acrylamide content was analysed by LC-ESI-MS/MS in the slices fried in seed and extra virgin olive oil. The Kennebec cultivar showed differences in its potential for acrylamide formation, which was primarily related to its relatively high asparagine and reducing sugars contents, respect the other local cultivars (particulary Quarantina). Values of acrylamide below detection limit (LOD) were found in Quarantina bianca genovese cultivar samples fried in extra virgin olive oil and peanuts seed oil and higher in peanuts seed oil fried potatoes of Kennebec cultivar.

Organogénesis directa in vitro a partir de hojas de la planta antiplasmodial solanum nudum dunal / Direct organogenesis in vitro from leaves of solanum nudum dunal – antiplasmodial plant

Solanum nudum Dunal (Solanaceae), es una especie vegetal con potencial para desarrollar un tratamiento quimioterapéutico contra la malaria. Este es el primer reporte de un protocolo rápido, eficiente y reproducible de organogénesis directa a partir de segmentos de hoja de plántulas in vitro de esta especie.Los segmentos de hojas de plántulas de 5 meses de germinadas fueron cultivados sobre medio Murashige y Skoog (MS) a mitad de sales y vitaminas, con diferentes concentraciones de Bencilaminopurina (BAP), en combinación con Acido Indolacético (AIA). Se evaluó también el efecto de la iluminación en periodos 0/45, 15/30 y 30/15 días oscuridad/ luz, sobre la inducción de brotes. Se registró un promedio alto de formación de brotes (4,83) en explantes cultivados en medio suplementado con 2,0 mg/L de BAP y 0,1 mg/L de AIA, bajo condición de iluminación por un periodo de 30/15 días oscuridad/luz. Luego de la inducción, los brotes obtenidos fueron transferidos a medio MS suplementado con 0,3 mg/L de Giberelina (GA3), y mantenidos en condiciones de luz donde también enraizaron. Las plántulas regeneradas se llevaron a condiciones de invernadero y fueron morfológicamente similares a las plantas madres.

Solanum nudum Dunal (Solanaceae) is a plant with a potential for developing chemotherapeutic treatments against malaria. This is the first report of a fast, efficient, and reproducible direct organogenesis protocol from leave segments from in vitro seed-grown plantlets.Leaves segments from 5 months old germinated plantlets were placed on half concentration Murashige and Skoog medium (MS), supplemented with several concentrations of Bencilaminopurin (BAP) combinated with Indolacetic Acid (IAA). Dark/ light incubation effect in periods 0/45, 15/30 and 30/15 dark/light days were evaluated on the buds induction. High frequency buds formation was shown (4,83) in explants cultured on MS supplemented with BAP 2,0 mg/L and AIA 0,1 mg/L under a period of 30 days of dark condition incubation. After induction, buds obtained were transferred to MS medium supplemented with gibberellic acid (GA3) 0,3 mg/L and maintained under artificial cool light, there the plantlets rooted. Regenerated plantlets were placed under greenhouse conditions and these were morphologically similar to donor plants.

The potato's contribution to population and urbanization: evidence from a historical experiment.

We exploit regional variation in suitability for cultivating potatoes, together with time variation arising from their introduction to the Old World from the Americas, to estimate the impact of potatoes on Old World population and urbanization. Our results show that the introduction of the potato was responsible for a significant portion of the increase in population and urbanization observed during the eighteenth and nineteenth centuries. According to our most conservative estimates, the introduction of the potato accounts for approximately one-quarter of the growth in Old World population and urbanization between 1700 and 1900. Additional evidence from within-country comparisons of city populations and adult heights also confirms the cross-country findings.

New series for agricultural prices in London, 1770­1914.

New annual series for the prices of major agricultural commodities sold in London markets between 1770 and 1914 are presented. These series are based on bimonthly observations drawn from newspaper market reports. The products covered are wheat, barley (grinding and malting), oats, potatoes, hay, butter, beef, mutton, and pork. Annual prices are calculated for both calendar and production years. The new series are compared to existing series.

Long-run effects on longevity of a nutritional shock early in life: the Dutch Potato famine of 1846-1847.

Nutritional conditions in utero and during infancy may causally affect health and mortality during childhood, adulthood, and at old ages. This paper investigates whether exposure to a nutritional shock in early life negatively affects survival at older ages, using individual data. Nutritional conditions are captured by exposure to the Potato famine in the Netherlands in 1846-1847, and by regional and temporal variation in market prices of potato and rye. The data cover the lifetimes of a random sample of Dutch individuals born between 1812 and 1902 and provide individual information on life events and demographic and socioeconomic characteristics. First we non-parametrically compare the total and residual lifetimes of individuals exposed and not exposed to the famine in utero and/or until age 1. Next, we estimate survival models in which we control for individual characteristics and additional (early life) determinants of mortality. We find strong evidence for long-run effects of exposure to the Potato famine. The results are stronger for boys than for girls. Boys and girls lose on average 4, respectively 2.5 years of life after age 50 after exposure at birth to the Potato famine. Lower social classes appear to be more affected by early life exposure to the Potato famine than higher social classes. These results confirm the mechanism linking early life (nutritional) conditions to old-age mortality. Finally, higher food prices at birth appear to reduce later life mortality of children of farmers from higher social classes. We interpret this as an income effect.

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.

Potato agriculture, late blight science, and the molecularization of plant pathology.

By the mid-1980s nucleic-acid based methods were penetrating the farthest reaches of biological science, triggering rivalries among practitioners, altering relationships among subfields, and transforming the research front. This article delivers a "bottom up" analysis of that transformation at work in one important area of biological science, plant pathology, by tracing the "molecularization" of efforts to understand and control one notorious plant disease -- the late blight of potatoes. It mobilizes the research literature of late blight science as a tool through which to trace the changing typography of the research front from 1983 to 2003. During these years molecularization intensified the traditional fragmentation of the late blight research community, even as it dramatically integrated study of the causal organism into broader areas of biology. In these decades the pathogen responsible for late blight, the oomycete "Phytophthora infestans," was discovered to be undergoing massive, frightening, and still largely unexplained genetic diversification -- a circumstance that lends the episode examined here an urgency that reinforces its historiographical significance as a case-study in the molecularization of the biological sciences.

Correspondence of Charles Darwin on James Torbitt's project to breed blight-resistance potatoes.

The most prolific of Darwin's correspondents from Ireland was James Torbitt, an enterprising grocer and wine merchant of 58 North Street, Belfast. Between February 1876 and March 1882, 141 letters were exchanged on the feasibility and ways of supporting one of Torbitt's commercial projects, the large-scale production and distribution of true potato seeds (Solan um tuberosum) to produce plants resistant to the late blight fungus Phytophthora infestans, the cause of repeated potato crop failures and thus the Irish famines in the nineteenth century. Ninety-three of these letters were exchanged between Torbitt and Darwin, and 48 between Darwin and third parties, seeking or offering help and advice on the project. Torbitt's project required selecting the small proportion of plants in an infested field that survived the infection, and using those as parents to produce seeds. This was a direct application of Darwin's principle of selection. Darwin cautiously lobbied high-ranking civil servants in London to obtain government funding for the project, and also provided his own personal financial support to Torbit.

Potential adoption and management of insect-resistant potato in Peru, and implications for genetically engineered potato.

This paper analyzes some important issues surrounding possible deployment of genetically engineered (GE) insect-resistant potato in Peru, based on a large farmer survey held in Peru in 2003. We found that the formal seed system plays a limited role compared with the informal seed system, especially for smallholder farmers. Although 97% of smallholder farmers would buy seed of an insect-resistant variety, a majority would buy it only once every 2 to 4 years. Survey data show that farmers would be willing to pay a premium of 50% on seed cost for insect resistant varieties. Paying price premiums of 25% to 50%, farmers would still increase their net income, assuming insect resistance is high and pesticide use will be strongly reduced. Of all farmers, 55% indicated preference for insect-resistant potato in varieties other than their current varieties. The survey indicates that smallholder farmers are interested to experiment with new varieties and have a positive perception of improved varieties. Based on these findings, and considering the difficulties implementing existing biosafety regulatory systems such as those in place in the U.S. and E.U., we propose to develop a variety-based segregation system to separate GE from conventionally bred potatoes. In such a system, which would embrace the spread of GE potatoes through informal seed systems, only a limited number of sterile varieties would be introduced that are easily distinguishable from conventional varieties.