| 1. |
- Abdel-Hameed, Amal Mohamed, et al.
(författare)
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Estimation of Potato Water Footprint Using Machine Learning Algorithm Models in Arid Regions
- 2024
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Ingår i: Potato Research. - : Springer Nature. - 0014-3065 .- 1871-4528.
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Tidskriftsartikel (refereegranskat)abstract
- Precise assessment of water footprint to improve the water consumption and crop yield for irrigated agricultural efficiency is required in order to achieve water management sustainability. Although Penman-Monteith is more successful than other methods and it is the most frequently used technique to calculate water footprint, however, it requires a significant number of meteorological parameters at different spatio-temporal scales, which are sometimes inaccessible in many of the developing countries such as Egypt. Machine learning models are widely used to represent complicated phenomena because of their high performance in the non-linear relations of inputs and outputs. Therefore, the objectives of this research were to (1) develop and compare four machine learning models: support vector regression (SVR), random forest (RF), extreme gradient boost (XGB), and artificial neural network (ANN) over three potato governorates (Al-Gharbia, Al-Dakahlia, and Al-Beheira) in the Nile Delta of Egypt and (2) select the best model in the best combination of climate input variables. The available variables used for this study were maximum temperature (Tmax), minimum temperature (Tmin), average temperature (Tave), wind speed (WS), relative humidity (RH), precipitation (P), vapor pressure deficit (VPD), solar radiation (SR), sown area (SA), and crop coefficient (Kc) to predict the potato blue water footprint (BWF) during 1990–2016. Six scenarios (Sc1–Sc6) of input variables were used to test the weight of each variable in four applied models. The results demonstrated that Sc5 with the XGB and ANN model gave the most promising results to predict BWF in this arid region based on vapor pressure deficit, precipitation, solar radiation, crop coefficient data, followed by Sc1. The created models produced comparatively superior outcomes and can contribute to the decision-making process for water management and development planners.
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| 2. |
- Andersson, Björn
(författare)
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Epidemiology and Integrated Control of Potato Late Blight in Europe
- 2011
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Ingår i: Potato Research. - : Springer Science and Business Media LLC. - 0014-3065 .- 1871-4528. ; 54, s. 183-222
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Forskningsöversikt (refereegranskat)abstract
- Phytophthora infestans, the causal agent of late blight, is a major threat to potato production in northwestern Europe. Before 1980, the worldwide population of P. infestans outside Mexico appeared to be asexual and to consist of a single clonal lineage of A1 mating type characterized by a single genotype. It is widely believed that new strains migrated into Europe in 1976 and that this led to subsequent population changes including the introduction of the A2 mating type. The population characteristics of recently collected isolates in NW Europe show a diverse population including both mating types, sexual reproduction and oospores, although differences are observed between regions. Although it is difficult to find direct evidence that new strains are more aggressive, there are several indications from experiments and field epidemics that the aggressiveness of P. infestans has increased in the past 20 years. The relative importance of the different primary inoculum sources and specific measures for reducing their role, such as covering dumps with plastic and preventing seed tubers from becoming infected, is described for the different regions. In NW Europe, varieties with greater resistance tend not to be grown on a large scale. From the grower’s perspective, the savings in fungicide input that can be achieved with these varieties are not compensated by the higher (perceived) risk of blight. Fungicides play a crucial role in the integrated control of late blight. The spray strategies in NW Europe and a table of the specific attributes of the most important fungicides in Europe are presented. The development and use of decision support systems (DSSs) in NW Europe are described. In The Netherlands, it is estimated that almost 40% of potato growers use recommendations based on commercially available DSS. In the Nordic countries, a new DSS concept with a fixed 7-day spray interval and a variable dose rate is being tested. In the UK, commercially available DSSs are used for c. 8% of the area. The validity of Smith Periods for the new population of P. infestans in the UK is currently being evaluated
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| 3. |
- Bengtsson, Therese, et al.
(författare)
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Biosurfactants Have the Potential to Induce Defence Against Phytophthora infestans in Potato
- 2015
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Ingår i: Potato Research. - : Springer Science and Business Media LLC. - 0014-3065 .- 1871-4528. ; 58, s. 83-90
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Tidskriftsartikel (refereegranskat)abstract
- Potato late blight caused by Phytophthora infestans is one of the most destructive plant diseases worldwide. Currently, its management mainly relies on the frequent use of synthetic chemicals, and there is a need to develop more sustainable strategies. Biosurfactants produced by fluorescent pseudomonads have been shown to rapidly, within 1 min, cause zoospore lyses. This study investigated if the biosurfactant-producing strain Pseudomonas koreensis 2.74 and its biosurfactants have the potential to induce resistance in potato to late blight. The experiments were performed with treatments of whole plants of the susceptible potato cultivar Bintje and the partially resistant cultivar Ovatio. A significant disease reduction and an induced secretion of proteins such as pathogenesis-related (PR) protein 1, within the leaf apoplast, were observed in the potato cultivar Ovatio after treatment with the biosurfactant at a concentration of 1 mg ml(-1). No significant effects on disease development were observed after treatment with the bacterial suspension of Pseudomonas koreensis 2.74.
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| 4. |
- Ekelöf, Joakim, et al.
(författare)
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Inter-Row Subsoiling and Irrigation Increase Starch Potato Yield, Phosphorus Use Efficiency and Quality Parameters
- 2015
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Ingår i: Potato Research. - : Springer Science and Business Media LLC. - 0014-3065 .- 1871-4528. ; 58, s. 15-27
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Tidskriftsartikel (refereegranskat)abstract
- Soil compaction due to the intensive use of heavy machinery is often a problem in potato production. Compaction can limit vertical root growth, water and nutrient uptake, and air and water infiltration, resulting in substantial yield reductions. This study examined the effects of inter-row subsoiling and irrigation on potato yield, tuber quality and phosphorus use efficiency (PUE) in three experiments in southern Sweden on soils with a documented plough pan at 25-30 cm. Potato (Solanum tuberosum L.) was grown in plots treated with inter-row subsoiling to a depth of 55 cm post planting, but prior to the start of root development, or in non-subsoiled plots. In addition, the interaction between inter-row subsoiling and irrigation was investigated under three different irrigation strategies: control (non-irrigated), intensive irrigation and moderate irrigation. Inter-row subsoiling significantly increased average starch yield, phosphorus use efficiency and total uptake of phosphorus in the three experiments. Irrigation significantly increased starch yield and tuber quality. Potato quality was significantly improved by a decrease in the incidence of common scab in the intensive irrigation regime, but the incidence of green tubers increased in the subsoiled plots. No significant interaction between tillage treatment and irrigation strategy was observed.
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| 5. |
- Eriksson, Dennis, et al.
(författare)
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Overview and Breeding Strategies of Table Potato Production in Sweden and the Fennoscandian Region
- 2016
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Ingår i: Potato Research. - : Springer Science and Business Media LLC. - 0014-3065 .- 1871-4528. ; 59, s. 279-294
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Tidskriftsartikel (refereegranskat)abstract
- Recent reductions in the public commitment to potato breeding in Sweden, Norway and Finland call for an evaluation of the current situation regarding the commercial basis for, and structure of, potato breeding in these countries. We here review the extent of cultivation, processing and consumption of table potato in Sweden, as well as provide an overview of the potato breeding tools and programmes in the three countries. We then discuss various strategies to provide long-term stability and increase the impact of public potato breeding, based on the similar overall conditions for potato cultivation across the Fennoscandian region. The conclusions are twofold; first, an increased long-term funding of the public potato breeding programmes is necessary to maintain a minimum level of material, and second, a coordination of the breeding activities in the Fennoscandian region would be of great benefit to all involved stakeholders and allow an enhancement of the current national breeding programmes. In addition, we propose a minimum first field year population size for potato breeding.
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| 6. |
- Hagman, Jannie, et al.
(författare)
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Cultivation Practices and Potato Cultivars Suitable for Organic Potato Production
- 2009
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Ingår i: Potato Research. - : Springer Science and Business Media LLC. - 0014-3065 .- 1871-4528. ; 52, s. 319-330
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Tidskriftsartikel (refereegranskat)abstract
- To identify the most important agronomic measures and cultivar traits in Swedish organic potato production, multivariate analyses were performed on a set of data from a series of field trials carried out in Sweden during a 7-year period. The effects of soil parameters, cultivar, year and geographical location on potato characteristics were investigated. Soil parameters including fertility level had strong and significant effects on potato characteristics, explaining 53% of total variation. Variables related to the duration of haulm growth were other dominant factors in the variation. While P and K fertilization increased yields, N fertilization had little effect on yield and a negative effect on the time to emergence. The N requirement of potatoes ranges from 2.5 to 5.9 kg ha(-1) per ton of tuber yield and was met in these trials. The results implied the timing of N application is important for yield. It was concluded that the importance of P and K fertilization is underestimated in organic production, and that the most important cultivar trait in achieving acceptable yield is long-lasting foliage, which is a characteristic of cultivars resistant to Phytophthora infestans. Three of the cultivars tested (Lady Balfour, Cicero and Sarpo Mira) had a yield > 3.5 kg m(-2), which is high in Swedish organic production.
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| 7. |
- Hagman, Jannie
(författare)
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Pre-sprouting as a Tool for Early Harvest in Organic Potato (Solanum tuberosum L.) Cultivation
- 2012
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Ingår i: Potato Research. - : Springer Science and Business Media LLC. - 0014-3065 .- 1871-4528. ; 55, s. 185-195
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Tidskriftsartikel (refereegranskat)abstract
- Earlier harvest of potatoes (Solanum tuberosum L.) can be achieved by different pretreatments of the seed tubers. In factorial field trials in 2008-2010, two different pre-sprouting methods were evaluated: conventional pre-sprouting of tubers and pre-sprouting of tubers with stimulation of adventitious root formation (PR). The results were compared with those for untreated seed tubers stored at 4 °C until planting (control). One variety was included in three trials, and two varieties were included in one trial. The new PR method was intended to give faster development and tuber initiation than conventional pre-sprouting, which can be of value when the growing season is restricted or when early harvest is important. Plant emergence, leaf necrosis (as a measure of maturity) and incidence of late blight were assessed during the growing season. After harvest, tuber fresh weight, size and density were assessed. It was found that pre-sprouting treatments gave on average 7 days earlier emergence compared with the control. Necrosis began earlier in pre-sprouted treatments in all cases except for the late variety Sarpo Mira. In 2008 and 2009 potato late blight struck late, after onset of senescence, but in 2010 it struck earlier and the pre-sprouted treatments proved more susceptible than the control. Total tuber yield was 7-24% higher on average in all pre-sprouted treatments in the different field trials. Tests on time of harvest showed that the advantage for the pre-sprouting treatments was maintained during the season, but the difference with the control decreased with time. When the different pre-sprouted treatments were compared, the new PR method proved to be not better than conventional pre-sprouting
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| 8. |
- Wiik, Lars
(författare)
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Potato Late Blight and Tuber Yield: Results from 30 Years of Field Trials
- 2014
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Ingår i: Potato Research. - : Springer Science and Business Media LLC. - 0014-3065 .- 1871-4528. ; 57, s. 77-98
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Tidskriftsartikel (refereegranskat)abstract
- During 1983-2012, three field trials per year were performed in each of the three southernmost counties in Sweden to test different fungicide programmes aiming to control late blight, primarily in the very susceptible potato cultivar Bintje. A dataset with results from these field trials was used (i) to examine possible changes in the appearance and behaviour of late blight attack over the years, (ii) to investigate the relationship between late blight in foliage and tuber blight, (iii) to investigate the relationship between late blight and tuber yield and (iv) to identify any correlations between different variables in the dataset. Late blight reached epidemic proportions, i.e. 75% disease severity in the untreated control, in the majority of the field trials. The estimated first attack of late blight was earlier in many field trials after 1998. Differences between years and regions were great in terms of date of the first attack and how the attack developed during the season. For example, in 2002-2005 and 2007, the first attack occurred 40-55 days after planting (DAP), compared with 95-108 DAP in 1994 and 1996. In 1994, 2006 and 2009-2011, the attacks increased from first symptoms to 65% disease severity in the untreated control within 16-21 days, compared with 35-40 days in 1995, 1999 and 2002. The relationship between foliage late blight and tuber blight was weak with the best match found at high disease severity late in the growing season (r = 0.33; p < 0.001). The relationship between blight-free tuber yield and start of the first attack indicated a yield increase of 287 kg/day (R-2 = 0.27) for every day's delay in first attack. Using the DAP for 65% disease severity in the untreated control improved the correlation (R-2 = 0.64) and indicated a yield increase of 534 kg/day for every day's delay in first attack. The later the onset of attack, the higher the blight-free tuber yield in treated plots. In general, significant correlations were found between blight-free tuber yield, size fractions of tuber yield, date of first late blight attack, date of different degrees of disease severity, disease severity, date of treatment, treatment measures and maintenance.
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| 9. |
- Stridh, Linnea, et al.
(författare)
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Field and Management Factors Can Reduce Potato Early Blight Severity: an Observational Study on Farms Combined with Field Trials in Southern Sweden
- 2024
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Ingår i: Potato Research. - 0014-3065. ; 67, s. 833-859
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Tidskriftsartikel (refereegranskat)abstract
- Alternaria solani is causing early blight and thereby yield reduction in the potato production. The pathogen is today mainly controlled by fungicide applications. The severity of early blight can vary largely among fields. The aim of this study was to gain understanding of what field and management parameters are the most important for early blight severity to create more farm-specific fungicide treatment recommendations. Over three seasons, 2019-2021, 52 field plots were observed at farms in southern Sweden. In each field a 24 m x 24 m plot was left untreated against early blight. However, late blight fungicides were applied. The disease severity was scored twice in the untreated plot and information about various soil/plant parameters and farmer's management was collected from each field. In addition to the observational study, field trials were performed in 2021 and 2022, evaluating the effect of potassium fertiliser levels on severeness of infection. We found that the soil composition was of significant importance for the severity of infection, in particular the sand, clay, and potassium content. The early blight severity was directly positively correlating with a high sand content. Low levels of leaf potassium increased the severity of early blight infection, and this observation was confirmed in field trials where different levels of potassium fertiliser were applied. Further no reduction in disease severity was observed with a four-year crop rotation. With knowledge about field and management factors that influence disease, field-specific recommendations can be developed supporting an integrated pest management strategy for early blight to reduce and optimise the fungicide usage.
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| 10. |
- Zaigham, Mehreen, et al.
(författare)
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Large gaps in the quality of healthcare experienced by Swedish mothers during the COVID-19 pandemic : A cross-sectional study based on WHO standards
- 2022
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Ingår i: Women and Birth. - : Elsevier BV. - 1878-1799 .- 1871-5192. ; 35:6, s. 619-627
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Tidskriftsartikel (refereegranskat)abstract
- Background and Problem: Existing healthcare systems have been put under immense pressure during the COVID-19 pandemic. Disruptions in essential maternal and newborn services have come from even high-income countries within the World Health Organization (WHO) European Region. Aim: To describe the quality of care during pregnancy and childbirth, as reported by the women themselves, during the COVID-19 pandemic in Sweden, using the WHO ‘Standards for improving quality of maternal and newborn care in health facilities’. Methods: Using an anonymous, online questionnaire, women ≥18 years were invited to participate if they had given birth in Sweden from March 1, 2020 to June 30, 2021. The quality of maternal and newborn care was measured using 40 questions across four domains: provision of care, experience of care, availability of human/physical resources, and organisational changes due to COVID-19. Findings: Of the 5003 women included, n = 4528 experienced labour. Of these, 46.7% perceived a poorer quality of maternal and newborn care due to the COVID-19. Fundal pressure was applied in 22.2% of instrumental vaginal births, 36.8% received inadequate breastfeeding support and 6.9% reported some form of abuse. Findings were worse in women undergoing prelabour Caesarean section (CS) (n = 475). Multivariate analysis showed significant associations of the quality of maternal and newborn care to year of birth (P < 0.001), parity (P < 0.001), no pharmacological pain relief (P < 0.001), prelabour CS (P < 0.001), emergency CS (P < 0.001) and overall satisfaction (P < 0.001). Conclusion: Considerable gaps over many key quality measures and deviations from women-centred care were noted. Findings were worse in women with prelabour CS. Actions to promote high-quality, evidence-based and respectful care during childbirth for all mothers are urgently needed.
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