Ha Of Potatoes Research Articles

Transformative crop insurance solution with big earth data: Implementation for potato in India

ContextCrop insurance has become an indispensable risk management tool in the agricultural sector because globally crops are being exposed to multiple hazards. The lack of reliable crop yield data has impacted the sustenance of area-yield crop insurance schemes. Index-based insurance, which links pay-outs to crop performance proxies rather than measured losses, is being explored to improve the effectiveness of crop insurance contracts. ObjectiveThis paper presents an innovative crop insurance scheme that has replaced the existing ‘area-yield’ approach using bias-prone crop yield estimates with the ‘area-crop performance approach’ using objectively measured satellite indices. MethodSatellite-based crop mapping, satellite and weather-based crop health indicators, field data collection and analysis, composite index generation, and insurance loss assessment are major tasks in the project. Data of Sentinel-1 and 2 satellites, weather datasets and mobile app-based field data from transplantation to harvesting of the crop constituted a huge repository of the database in this project. Metrics derived from established satellite indices, such as NDVI, LSWI and Backscatter, along with weather indices, were synthesized into a composite index of crop performance called Crop Health Factor (CHF). The input data matrix of the CHF model included eight input indicators. After data normalization, weights for these indicators were generated using the entropy technique, a proven method of information measurement that produces balanced relationships and unbiased weights. The CHF was first generated with data from the past years (2016–2019), and the resulting weights were then applied to the normalized data of the current year (2020). ResultsThe current crop insurance scheme, using CHF data instead of yield data, was implemented in the state of West Bengal, India, covering about 500,000 ha of potato across and one thousand insurance units in the 2020 crop season. The CHF and yield data from past years showed similar patterns in the majority of cases. The indemnity level was set at 70 % of the normal CHF, which was the average CHF of past years. Loss assessment and compensation payouts for the current year were determined by the extent of CHF reduction beyond the indemnity level. SignificanceThis new index-insurance scheme has many advantages over the conventional yield-based scheme in terms of transparency, objectivity and ease of implementation. There is scope for improving the composite index with additional features. Such technology-driven index-insurance schemes for field crops are expected to bring a paradigm shift in the crop insurance sector, giving rise to new business models and benefitting all the stakeholders.

Management of early blight (Alternaria solani Sorauer) in processing potato crops with new fungicides – phytopathological and physiological implicancies

In Argentina, 75,000 ha of potatoes are grown annually and close to 25% of this area is grown for the processing industry. Among the impact of other diseases and pests, early blight (Alternaria solani Sorauer) infections could reduce yield by up to 20%. Hence, the objective of this work was to assess the impact of a new-generation of fungicides (Boscalid + Pyraclostrobin - Bellis®- BASF Argentina) on early blight management. Results showed that foliar applications of Boscalid + Pyraclostrobin, were not only effective in controlling the disease, but they also promoted a stay-green effect and a positive impact on yield and quality in the processing cultivars Daisy and Innovator. Besides, Boscalid + Pyraclostrobin treated tubers showed an increased level of phytoalexins and stress oxidative enzymes related to defense mechanisms, such as peroxidase and polyphenol oxidase. Also, an increased deposition of cell wall reinforcement components such as phenols and lignin was observed. Thus, management of these processing varieties with Boscalid + Pyraclostrobin not only contributes to protect the foliage, but also increase yield and quality and induces the development of systemic acquired resistance that improves tuber storability.

Predicting climate-change-caused changes in global temperature on potato tuber moth Phthorimaea operculella (Zeller) distribution and abundance using phenology modeling and GIS mapping

Originating from the Andean region and co-evolved with its food plant, the potato (Solanum sp.), the potato tuber moth Phthorimaea operculella (Zeller) has become an invasive potato pest globally. The hypothesis of our present study was that the future distribution and abundance (damage potential) of this pest will be greatly affected by climate-change-caused changes in temperature. We used a process-based climatic phenology model for P. operculella and applied three risk indices (establishment-, generation, and activity index) in a geographic information system (GIS) environment to map and quantify changes for climate change scenarios of the year 2050 based on downscaled climate-change data of the scenario A1B from the WorldClim database. All applications and simulations were made using the Insect Life Cycle Modeling (ILCYM) software recently developed by The International Potato Center, Lima, Peru. The study concludes that there are three possible main scenarios of changes that may simultaneously occur: (1) the P. operculella damage potential will progressively increase in all regions where the pest already prevails today with an excessive increase in warmer cropping regions of the tropics and subtropics. In regions where P. operculella is established and develops >4 generations per year, economic losses are likely to occur; under the current climate, >4 generations are developed on 30.1% of the total potato production area worldwide, which will increase until the year 2050 to 42.4%, equal to an increase of 2,409,974ha of potato under new infestation. (2) A range expansion in temperate regions of the northern hemisphere with additionally 8.6% (699,680ha), 4.2% (32,873ha), and 2.7% (234,404ha) of the potato production area under higher risk in Asia, North America, and Europe, with moderate increases of its damage potential. (3) A range expansion in tropical temperate mountainous regions with a moderate increase of its damage potential; e.g., in Bolivia, Ecuador and Peru 44,281ha, 9569ha, and 39,646ha of potato will be under new risk of infestation. The ILCYM software allowed a detailed analysis of possible climate-change-induced changes in temperature on P. operculella distribution and damage potential. Further, this tool offers means of overcoming limitations in predictions and mapping experienced with climate data interpolation and resolution by spatial point-by-point simulations at locations of interest. The methodology is proposed as a very helpful tool for adaptation planning in integrated pest management.

First Report of Zebra Chip Disease and "Candidatus Liberibacter solanacearum" on Potatoes in Oregon and Washington State.

In August of 2011, potato (Solanum tuberosum) tubers grown in the lower Columbia Basin of southern Washington State and northern Oregon were observed with internal discolorations suggestive of zebra chip disease (ZC). Symptoms included brown spots, streaks, and stripes in and near the vascular tissue, typical of ZC (1). Symptoms were observed in cvs. Alturas, Russet Norkotah, Pike, Ranger Russet, Umatilla Russet, and Russet Burbank. Foliar symptoms on plants that produced symptomatic tubers included purple discoloration in upper leaves, leaf rolling, axial bud elongation, chlorosis, leaf scorch, and wilt. Tissue was taken from two symptomatic tubers each of cvs. Alturas and Russet Norkotah, three tubers of cv. Umatilla Russet, and one tuber of cv. Pike. These tubers were tested by PCR for "Candidatus Liberibacter solanacearum", an unculturable alphaproteobacterium associated with ZC (1,4). Primers specific for the 16S rDNA were CLipoF (4) and OI2c (3), and primers OMB 1482f and 2086r were specific for the outer membrane protein (2). All of these samples, except one Umatilla tuber, were positive for the bacterium. The 16S rDNA and OMB amplicons from one symptomatic tuber each of Alturas (from Washington) and Pike (from Oregon) were cloned and three clones of each were sequenced. BLAST analysis of the consensus sequences confirmed "Ca. L. solanacearum". The 16S sequences (1,071 bp) from the two tubers were identical and showed 99 to 100% identity to a number of 16S rDNA sequences of "Ca. L. solanaceaum" in GenBank (e.g., Accession Nos. HM246509 and FJ957897). The 16S rDNA sequences were deposited in GenBank as Accession Nos. JN848751 and JN848753. Consensus sequences of the two OMB clones (605 bp; deposited in GenBank as Accession Nos. JN848752 and JN848754) were identical and showed 97% identity to the two "Ca. L. solanacearum" OMB sequences in GenBank (Accession Nos. CP002371 and FJ914617). Potato psyllids (Bactericera cockerelli Sulc), the vector of "Ca. L. solanacearum", were present in ZC-affected fields in Oregon and Washington and the bacterium was confirmed by PCR in 5 to 10% of 128 adult psyllids collected from two fields. On the basis of foliar and tuber symptoms, specific PCR amplification with two primer pairs, sequence analyses, and the presence of Liberibacter-infected potato psyllids, ZC and "Ca. L. solanacearum" are present in potatoes in Oregon and Washington State. Washington and Oregon together grow ~80,000 ha of potatoes. ZC has caused significant economic damage to potatoes in Texas, Mexico, Central America, and New Zealand (1). Therefore, ZC may pose a risk to agriculture in Oregon, Washington, and neighboring states. However, the potential for development of widespread and serious disease will depend upon the arrival time and number of infective potato psyllids entering the region.

Reproduction and Feeding Behavior of <I>Myzus persicae</I> on Four Cereals

Green peach aphid, Myzus persicae (Sulzer), does not overwinter outdoors in Minnesota; it arrives each spring on low-level jet streams from the south. After arrival, anholocylic reproduction occurs on numerous herbaceous species, including many common weeds, before movement to potato, Solanum tuberosum L. In investigating aphid feeding behavior on barrier crops, we observed winter wheat, Triticum aestivum L., colonized by green peach aphid. The Northern Great Plains grows 94,000 ha of potatoes and 20.5 million ha of small grain cereals each year, the latter potentially providing an early emerging and widely distributed green peach aphid host to influence early season potato colonization. Life tables statistics indicated green peach aphid had its highest reproductive potential among cereals on winter wheat, with rye (Secale cereale L.) > barley (Hordeum vulgare L.) > oats (Avena sativa L.). Green peach aphid was found to colonize barley, rye, and winter wheat, but not oats. Mean generation time, net reproductive rate, doubling time, and finite rate of increase were significantly different between host plants. Electrical penetration graph technique indicated mean nonpenetration duration by green peach aphid was significantly different among plant species, and significantly longer on winter wheat than on the other cereals. Mean xylem phase duration was not significantly different among plant species but sieve element salivation was of longest duration on potato. Phloem sap ingestion (E2) was also significantly different among plant species with longest E2 duration on winter wheat. This study demonstrates that this aphid can effectively use key cereals at the vegetative stage.

First Report of the Occurrence of Potato Wart Disease Caused by Synchytrium endobioticum in Turkey.

Potato wart caused by Synchytrium endobioticum (Schilberszky) Pervical was observed in Turkey on different cultivars (Agria, Granola, Marabel, Marfona, Russet Burbank and Van Gogh) during the 2004 harvest season in the Misli (Bud) Plain where approximately 40,000 ha of potatoes are grown. This plain, lying between Nigde and Nevsehir provinces in the central-eastern Anatolia Region, has a predominance of sandy soils (60 to 80% sand) and climatic conditions suitable for production that has been a long-term monoculture using heavy fertilization with nitrogen (500 to 1,500 kg of N per ha) and phosphorus (200 to 500 kg of P2O5 per ha). The wart symptoms were observed on tubers but not on roots and stems. The warts were white, almost spherical, and softer in texture than the tuber tissue. Resting sporangia, observed within the fresh wart tissue using light microscopy, were light brown, spherical to ovoid and 50 to 70 μm in diameter. Soil surveys confirmed that resting sporangia were present in the fields where wart was observed. Resting sporangia were isolated from infected tubers and surrounding soil (2). An average of <1 sporangium per gram of soil was detected in the infested fields. Pathogenicity of the causal agent was demonstrated on 10 tubers of potato cv. Granola. Sprouts on the tubers were cut off at 2 mm above the tuber surface, the eye fields were ringed with warm vaseline using a sterile syringe without a needle and then inoculated by placing fresh cauliflower-like warts containing summer sporangia in the vaseline wells. The tubers were first incubated at 8 to 12°C for 48 h in the dark and after removing the wart tissue, placed in moist peat at 18°C and kept in an 8-h lighting period per day as described by Glynne-Lemmarzalh (1). Sporangia were reisolated from the white, fresh wart tissues observed 8 to 10 weeks later on the inoculated tubers. Two tubers inoculated with sterile tap water did not develop warts. Koch's postulates were fulfilled. Currently, approximately 20,000 ha of the Misli Plain are under official quarantine due to the finding of potato wart. Because of the large-scale occurrence in 2004, it is suspected that the pathogen entered Turkey 3 to 4 years earlier through importation of seed potato tubers from European countries. To our knowledge, this is the first report of the occurrence of wart on potatoes grown in Turkey. The importance of this occurrence in the middle of an area where 50% of Turkey potatoes are produced is duly noted.

The white potato cyst nematode (Globodera pallida) - a critical analysis of the threat in Britain

Over the last 30 years, there has been an epidemic of the white potato cyst nematode (wPCN, Globodera pallida). It has progressively replaced the yellow species (yPCN, G. rostochiensis) throughout most of England and Wales and is now a widespread problem. As damaging populations of wPCN are enormous (>109 eggs ha−1), several crops of potato cultivars resistant only to yPCN were required to produce this change. The threat it poses is reflected in an increase in the numbers of soil samples being tested and in nematicide use, which has increased to > 25 000 ha of potatoes being treated annually. Computer modelling shows that current management of wPCN is mostly ineffective and populations will continue to increase. The multiplication rate of wPCN is inversely related to its population density at planting and, because of this, modelling shows that sufficient eggs are likely to survive to enable large populations of wPCN to “rebound” following nematicide treatment. This is supported by recent trial results showing that wPCN population increase was almost as great in nematicides-treated plots as in the untreated. Modelling also showed that current rotations (typically potatoes once every 5 or 6 years) are too short to prevent wPCN populations from progressively increasing, even when used in conjunction with a nematicide. Similarly, except with avirulent populations, the partially resistant cultivars currently available will not prevent wPCN from increasing. However, as the effectiveness of partially resistant cultivars is independent of population density, they can be very effective when integrated with a nematicide. Unfortunately, only c. 8% of the potato area is planted with partially resistant cultivars, and much of that is in land not known to be infested with wPCN. Consequently, the current epidemic of wPCN is likely to become progressively more serious. However, many farmers are failing to recognise and respond to this threat until it is too late because of the slow rate of increase of wPCN, the difficulties of detecting small populations and the costs of nematicides. To respond to the current epidemic of wPCN, the greatest priority is to have available an increased number of commercially-attractive partially resistant cultivars.

The white potato cyst nematode (Globodera pallida) – a critical analysis of the threat in Britain

SummaryOver the last 30 years, there has been an epidemic of the white potato cyst nematode (wPCN, Globodera pallida). It has progressively replaced the yellow species (yPCN, G. rostochiensis) throughout most of England and Wales and is now a widespread problem. As damaging populations of wPCN are enormous (&gt;109 eggs ha−1), several crops of potato cultivars resistant only to yPCN were required to produce this change. The threat it poses is reflected in an increase in the numbers of soil samples being tested and in nematicide use, which has increased to &gt; 25 000 ha of potatoes being treated annually. Computer modelling shows that current management of wPCN is mostly ineffective and populations will continue to increase. The multiplication rate of wPCN is inversely related to its population density at planting and, because of this, modelling shows that sufficient eggs are likely to survive to enable large populations of wPCN to “rebound” following nematicide treatment. This is supported by recent trial results showing that wPCN population increase was almost as great in nematicides‐treated plots as in the untreated. Modelling also showed that current rotations (typically potatoes once every 5 or 6 years) are too short to prevent wPCN populations from progressively increasing, even when used in conjunction with a nematicide. Similarly, except with avirulent populations, the partially resistant cultivars currently available will not prevent wPCN from increasing. However, as the effectiveness of partially resistant cultivars is independent of population density, they can be very effective when integrated with a nematicide. Unfortunately, only c. 8% of the potato area is planted with partially resistant cultivars, and much of that is in land not known to be infested with wPCN. Consequently, the current epidemic of wPCN is likely to become progressively more serious. However, many farmers are failing to recognise and respond to this threat until it is too late because of the slow rate of increase of wPCN, the difficulties of detecting small populations and the costs of nematicides. To respond to the current epidemic of wPCN, the greatest priority is to have available an increased number of commercially‐attractive partially resistant cultivars.

Early potatoes in Italy with particular reference to Sicily

In Italy, the early potato cultivars of greatest economic significance are those grown off-season, in a cycle which is generally much earlier than the typical spring-summer cycle. Of the area given over to early potatoes in Italy, more than 90% is in the southern regions. The economic value of this production is due to its extraseasonality, which allows much of the early potato harvest to be sold on foreign markets. In Sicily, more than 5000 ha of potato are grown, with a high frequency of potato crops on small plots. Early potatoes are often rotated with various fruits and vegetables, and the length of the cycle is variable, from 100 to 140 days. Choosing the most suitable cultivar is the most complex aspect of early potato growing. Of the criteria used, tuber growth rate has shown most validity. In Sicily two cultivars are mainly grown: Sieglinde and the more recent but well-established Spunta. Agricultural techniques used for early potato cultivation vary depending on the area. An overview of the agronomic practices used in different areas is given in this paper.

SEXUALLY PROPAGATING POTATOES

The importance of sowing vigorous seed is particularly well recognized by commercial growers of small-seeded sexually propagated crops. The possibility of producing clean potato seed tubers with true potato seed (TPS) has existed in many developing countries since the seventies. In China, about 15,000 ha of potatoes are grown with seed tubers originally derived from TPS. The possibility to establish a fast field-stand and to produce a commercial crop of potatoes within 90 days after transplanting TPS seedlings has only been recently realized. This paper outlines the methodology used and the results obtained during 10 years of study focusing on the most critical factors involved in the production and preservation of high-quality TPS. Seed dormancy accounts for the most important difference between the undomesticated TPS and other related crops such as the tomato.

Yield levels of potato crops in Central Africa

The countries Burundi, Rwanda, Uganda and Zaire, sharing the Zaire-Nile Divide highlands, grow over 110 000 ha of potatoes annually. Farms are smaller than 1 ha and potato yields are about 7 t/ha. All cultivation is done manually and inputs such as fertilizers and pesticides are not used, due either to their unavailability or their high cost. Since 1980, national potato research programmes have started to operate in the area, focusing mainly on the introduction and screening of germplasm, the production and distribution of basic seed and improving the cultural practices with low-, medium- and high-cost means. Estimates for actual, aspired, attainable, experimental and potential yields in different agro-ecological zones are given and the priorities for the national programmes to close the yield gaps are discussed.

Overwintering en epidemiologie van Phytophthora infestans, tevens enige nieuwe bestrijdingsmogelijkheden

Primary foci of phytophthora. could be found in potato fields originating from diseased tubers and on refuse heaps. In De Streek (North Holland) the very susceptible variety Eersteling had I primary focus per 80 ha of potatoes. Infection from refuse heaps was there of minor importance. Only a small proportion of diseased tubers planted gave a primary focus. Spread from the primary foci was studied. Epidemics of phytophthora. under the prevailing weather conditions could be easily explained by spread from the primary foci. 'Field resistance' of the varieties plays a main role in epidemics. A method for testing it in the greenhouse was worked out. The disease could be controlled not only by spraying but also by careful inspection of seed potatoes and by eradication of primary foci in field and on refuse heaps. Heat treatment of tubers killed the fungus, but would hardly be applicable in practice.