Repository

The paper presents results of studies carried out from 2006 to 2009 which aimed to determine the influence of undersown crops plowed down in the autumn or left till spring in the form of mulch on table potato yielding. The following treatments were examined: control object (without undersown crops fertilization), farmyard manure, serradella, westerwold ryegrass, serradella — mulch, westerwold ryegrass — mulch. The content of dry mass and macroelements (N, P, K, Ca, Mg) were determined in undersown crops biomass. Table potatoes were grown directly after undersown crops fertilization. During potato harvest the yield of fresh tubers mass was determined and after that the marketable yield and the structure of tuber yield were determined. The obtained results allow to conclude that among undersown crops westerwold ryegrass gives the highest amount of dry mass in soil, and serradella the highest amount of macroelements. Serradella fertilization both left till spring in the form of mulch and plowed down fully replaced farmyard manure in potato cultivation. The highest shares of marketable and seed potato fractions, and the lowest share of small tubers was noted in combination fertilized with serradella in the form of mulch...

The aim of field experiment conducted in the years 2007–2009 in Department Agronomy of Plant Breeding and Acclimatization Institute, Division of Jadwisin was the determination of mineral nitrogen content in the soil after harvest of potato tubers representing three cultivars with low (cultivar Asterix), medium (cultivar Wiking) and high (cultivar Maryna) requirements for nitrogen. The experiment was carried out on the light soil fertilized organically with straw and aftercrop of white mustard. In these experiments 5 levels of nitrogen fertilization were applied: 0, 50, 100, 150 and 200 kg N∙ha-1 with the constant level of phosphorus 52.3 kg P∙ha-1 and potassium 149.4 kg K∙ha-1. Content of mineral nitrogen in the soil layers 0-30 cm and 30–60 cm rose as the N-fertilization doses increased. We detected significantly higher content of mineral nitrogen in the soil on plots with cultivars with low and medium requirements in comparison to cultivar with high requirements for this component. A dose of nitrogen above 100 kg N∙ha-1 influenced negatively the content of mineral nitrogen in the soil in case of cultivars with low and medium requirements for nitrogen. For cultivar with high requirements, dose of 200 kg N∙ha-1 did not influence negatively the content of mineral nitrogen in the soil, but the highest yield of tubers was obtained at the dose of 150 kg N∙ha-1. In the years (2008, 2009) favourable for high tuber yield, lower content of mineral nitrogen in the soil was noted...

The study was conducted in the northern region of Poland (Bonin near Koszalin) during years 2008–2010 on medium-heavy soil. The aim of the study was to determine the impact of four doses of nitrogen fertilization (40, 80, 120 and 160 kg N•ha-1) on tuber yield, including total, marketable, large tubers and seed tubers yield classes for three new varieties of table potatoes (Promyk, Tetyda, Wiarus). All of them are classified as mid-early cultivars and all were registered in 2008 into Polish national List of Agricultural Plant Varieties. Fertilizer influence on starch yield and some quality features was also evaluated. The highest yield was observed for variety Tetyda. The average (from all levels of applied fertilizer), total, marketable and large tuber yields were respectively: 55.5, 52.8 and 43.1 t•ha-1 for this variety and were significantly higher than for variety Promyk (respectively: 41.8, 36, 8 and 22.9 t•ha-1) and Wiarus (respectively 41.4; 39.3 and 32.2 t•ha-1). In the class of seed yield (size 30-50 mm) highest yield was produced by variety Promyk. It amounted to an average of 18.4 t•ha-1 and was significantly higher than for Tetyda (12.0 t•ha-1) and Wiarus (8.9 t•ha-1). The lowest yield of starch was observed for variety Promyk (average 5.85 t•ha-1). It was significantly lower than for the variety Tetyda (7.16 t•ha-1) and Wiarus (6.29 t•ha-1). Different doses of nitrogen fertilization were needed by varieties Promyk (113 kg N•ha-1) and Wiarus (127 kg N•ha-1) to produce similar maximum yield of tubers (47.9 t•ha-1). The variety Tetyda needed 133 kg N•ha-1 to produce maximum tuber yield (65 t•ha-1). The dose of nitrogen fertilization had no significant effect on the losses due to evaporation, rot and sprouting (counted together) and the number of tubers with hollow centre...

A field experiment was carried out in 2008–2010. The experiment was designed as a two-factor randomized block with three replicates. The research aimed at determination of the effect of soil fertilizer UGmax on the total yield, yield of large tubers and structure of yield of two potato cultivars. The tuber yields largely depended on application of UGmax, cultivar properties and weather conditions in the years of investigations. After applied the soil fertilizer UGmax, as compared to the control object, the obtained yields increased by 27.2 and 35.3%...

A field experiment was carried out in 2005–2007. The experiment was designed as a two factor randomized block with three replicates. Factors examined in the experiment included two potato cultivars — Irga and Balbina and four weed control methods: application of herbicides: Plateen 41,5 WG, Racer 250 EC, Sencor 70 WG and control object – mechanical weeding. The work was aimed at evaluating the effectiveness of the weed control methods on the number of weeds and assessing their effects on yielding of two cultivars of table potato. The lowest number of weeds before closing of potato rows and before harvest of tubers was noted after treatment performed with the use of herbicide Sencor 70 WG. The results indicated significant negative relationships between the number of weeds and potato tuber yield...

The main purpose of the presented study was to evaluate the occurrence of tuber shape defects in the potato cultivars and advanced breeding materials from the same potato breeding centers, that were grown on sandy soil in natural moisture conditions. The study used data on the occurrence of growth cracks and misshaped tubers of potato cultivars and advanced breeding materials which were collected during the varietal assessment experiments and a research project financed by Ministry of Agriculture. The field experiment was performed in the years 2008–2011 at IHAR — PIB, Potato Agronomy Department in Jadwisin. The assessment included 156 potato genotypes. The obtained data were analyzed statistically with SAS Enterprise Guide 4.3. The results of study indicate that the yield of new genotypes was characterized by a higher occurrence of misshaped tubers, however, share of tubers with cracks was lower in new genotypes than in registered cultivars...

The main of experiment was the evaluation of the storage losses and sprouting dates in different storage temperatures (3°C, 5°C, 8°C). New table: (Aruba, Cyprian, Elanda, Finezja, Flaming, Justa, Zagłoba) and starch (Kuras, Sekwana, Tukan, Zuzanna) potato cultivars were assessed depending on weather factors in vegetation period. After storage at temperatures of 3°C, 5°C, 8°C, natural losses, diseases losses, sprouting dates and mass of sprouts were estimated. The natural losses of potato varieties stored at 3°C, and 5°C were on the similar level (8.3% and 7.4%). Only potatoes stored in higher temperature (8°C) had higher natural losses (9.8%), than stored in temperature 3°C and 5°C. The average of potato losses caused by diseases amounted from 0.6% to 4.60%. Sprouting date depended on cultivar, on the storage temperature and vegetation conditions. Potatoes stored at temperature 8°C begun sprouting from 1st decade of November (Flaming) till 1st decade of February (Finezja), depending on cultivar. The storage at 5°C caused delay in the beginning of sprouting about 6 decades in relation to storage at 8°C. Vegetation conditions had an influence on sprouting date, natural losses and amount of diseases during storage...

The IHAR — PIB in Bydgoszcz received in 2010 eleven samples of infected sugar beet roots and soil. The samples were taken from areas of the following provinces: Kujawy-Pomerania, Pomerania and Warmia-Masuria. The main purpose of the tests was to examine the occurrence of Rhizoctonia solani. The content of macronutrients, salinity and pH were evaluated in the samples of the soil. First, the soil was placed on trays and then sugar beet seeds were sown. The occurrence of various fungi genera, including Fusarium, Aphanomyces, Pythium, Rhizoctonia, Verticillium, Cladosporium and Alternaria was noted. R. solani was detected in the soil obtained from Minikowo and Sypniewo areas (Kujawy-Pomerania) and also from Wandowo area (Pomerania). After growth in the mentioned soils the following R. solani infection rates on the sugar beet seedlings were found: 15.3% (on average for Janosik and Jenna sugar beet cultivars), 7.9% (Janosik) and 15.7% (Janosik). Frequent observations and examinations of the microscopic specimen of infected sugar beet tissue showed simultaneous occurrence of many fungi, among which fungi such as genera Aphanomyces, Fusarium, Pythium, Verticillum and Rhizoctonia dominated. The studies of received roots and soils samples confirmed that in three cases R. solani was present in the soil as well as on the plant...

The aim of research was to explain mode of inheritance of the lucerne mutation that causes the formation of panicles instead of racemes on stems. Panicles on mutant plants consisted of a lot of branches that caused several fold increase of flower numbers in inflorescences. Application of this character in lucerne breeding creates new opportunities to increase its seed yield potential. The inheritance of this character was studied in S1 and S2 progenies obtained by selfing a mutant plant, as well as in F1, F2 and F3 generations of hybrids obtained by crossing plants that produce racemes with S2 mutant progenies. The analysis of segregation in the selfed progenies of the mutant plants and in F1 – F3 progenies of the hybrids showed that the character of panicle inflorescence is controlled by single gene in the configuration of four recessive alleles pi pi pi pi (pi — panicle inflorescence)...

Potato is a valuable food product. It is of relatively low caloric value and moderate glycaemic load. Potato contains valuable protein and significant quantities of essential vitamins and mineral compounds, as well as necessary dietary fibre. Anti-nutritive substances are found in potato in very low quantities, mostly, localized in the skin on just under it. Thanks to that, the most of anti-nutritive compounds is removed during culinary treatment. Potato does not accumulate harmful compounds from poisoned environment. Potato food products make easy consumption possible without complicated preparatory operations. Native or processed potato starch and its derivatives are necessary to obtain suitable quality products in nearly all branches of food industry...

The aim of the study was to examine changes of the scale and the technology of potato cultivation in the country in recent years. The basis for these analyses was the data from CSO and also some collected by the IHAR — PIB Division Jadwisin in cooperation with the ODR in the national monitoring studies in recent 15 years. The results show, that with decreasing scale of potato cultivation in the country, continuous changes in the technology of potato cultivation follow and the process of technology polarization is correlated with the scale of cultivation of this species on the farm and the direction of the use of yield. Against the background of the decreasing total number of farms that are growing potatoes, the number of farms producing this species for multi-purpose use is undergoing the fastest reduction. However, a number of farms specializing in production of potatoes for strictly specified purposes is increasing...

The purpose of this study was to determine the effects of potato slice thickness and frying temperature on selected quality parameters of kettle-style chips. Potatoes of cv. Lady Claire (typical for the production of chips) were used for this investigation. Tubers after washing, were cut into slices 1.2, 1.7 and 3 mm thick, washed in cold water and - after drying (paper towels) - fried in rapeseed oil at three temperatures: 150, 165 and 180°C. In the tested potato chips we determined: moisture by drying the samples until reaching constant weight in convection oven at 105°C, the fat content by a Soxhlet extraction method, texture – by an objective method using the Instron 5544 apparatus and the colour – by an objective method using a Minolta spectrophotometer type CM-5. It was found that the increasing thickness of the potato slices reduced the oil absorbed by chips. Frying temperature affected the fat content only in chips obtained from the thickest slices, which absorbed larger amounts of fat along with raising the temperature of frying. Chips differed in consistency. Hardest texture, was observed in the thickest chips from potato slices, and the most delicate in the thinnest ones...

The aim of the work was to study the effect of frying temperature on properties of potato chips fried in classical and pressure fryers. We showed that potato chips fried in pressure fryer exhibited lower dehydration in comparison with chips fried at the same temperatures in classical fryers. Pressure fried potato chips had 30% less of fat content. The texture of chips obtained by frying in pressure fryer was harder. Potato chips fried at highest temperature, in both types of fryers, exhibited lowest hardness. Pressure frying influenced colour intensity of potato chips. In organoleptic assessment higher notes were obtained by classical fried potato chips. Pressure frying allowed to obtain potato chips with lower fat content, more intensive colour, but harder and less crispy texture...

The objective of the paper was to assess the effect of RS modified starch on in vivo digestibility in Wistar rats. In the experiment, 40 12-week-old rats were used. Animals were fed 4 different diets: control pregelatinised potato starch and 3 diets with resistant starches (AO, WT, RS). Determination of nutritional and growth parameters have been carried out. The in vivo digestibility determined by standard method was made as well. It was found that 50% addition of starch preparations resistant to amylolitycal enzymes to the diet increased the water content in fecal. It proves that RS preparations are able to bind water  and accelerate the feed passage. Digestibility and protein, fat and sugars content measured by balance method were hardly distinguishable between analyzed diets. The preparation marked RS-3 showed the lowest digestibility...

The aim of this investigation was to determine the effect of different blanching and drying temperatures used during the laboratory production of dehydrated cooked potato on the vitamin C content in semi-product and ready product. Based on the investigation it was stated that the production process of dried cooked potato had the influence on the loss of vitamin C. The largest changes in the content of vitamin C occurred after thermal processes: blanching and drying. The higher the temperature of the blanching, the greater was the loss of vitamin C. The differences in the content of this compound between products from blanching at temperature of 95°C and 75°C were 28%. Pre-drying process had the influence on the loss of vitamin C in potatoes. Potatoes dried at temp. 160°C were containing 51% less of the investigated vitamin than the ones dried at temp. 130°C. Ready dried potato contained less than 1% of the initial amount of vitamin C in the raw material...

In the years 2008–2010 the experiment concerning quality of potatoes grown in two farming systems was carried out in two places in Poland: Jadwisin- central part and Osiny — east- south. The marketable quality of tubers (external and internal disorders), was tested. Following factors were assessed : crop production system, place of growing, cultivar and year of investigation. We showed  that the climatic conditions during vegetation period and genotype had the largest influence on tuber external and internal disorders. Crop production system and place of growing had a smaller effect...

The aim of this study was an attempt to produce and determine the thermal insulation properties of biodegradable materials produced using potato starch and acetylated potato starch. Natural potato starch, acetylated potato starch and their mixture were subjected to extrusion at three different temperatures. Extruded material was obtained in the form of beads. In addition, the extruded starch was formed into rigid shapes with a thickness of 20 mm. In order to verify the thermal conductivity we measured the time in which the temperature rise by heating the tested material (beads and rigid shapes) at a specific thickness. As a result of the experiment it was stated that shapes, which were made from extruded natural potato starch, had a lower thermal conductivity comparing to the loose beads of the extruded starch. Among the extruded starch, that starch that was extruded at temperatures 140, 150, 170°C, showed highest thermal conductivity. The natural extruded potato starch comparing to the acetylated extruded starch or mixture natural and acetylated (1:1) extruded potato starch is characterized by a highest thermal conductivity...

The aim of this study was to determine the property of thermal insulation of potato, rice, maize, wheat and tapioca starches. In addition, potato starch was separated using the sieve shaker device AS 200 by Retsch. The obtained starch fractions were: 20–24μm, 25–31μm, 32–38μm. In order to verify the thermal conductivity, we measured the time in which the temperature rise after heating the tested material of a specific thickness. Moisture content of the material was: 8 or 25%. As the results of the experiment it was stated that rice starch is characterized by the highest thermal conductivity. Potato starch and wheat starch had a lower thermal conductivity comparing to another tested starches. Fractions of starch granules differed in their thermal conductivity...

The purpose of the work was to determine the properties of extrudates obtained from potato starch and potato starch with kaolin addition during storage in different conditions. The starch was subjected to extrusion process in a single screw laboratory Brabender extruder (of 20DN type). The extruded starch was stored in drier chamber and controlled environment chamber. Storage periods were defined as follows: 1, 3, 6, 9, 14 and 21 days. After this time, we determined: moisture content, expansion ratio, elongation at breaking and bending moment in prepared samples. The properties of extrudates were different and depended on the kind of extruded starch, time and conditions of storage. Extrudates produced from starch with kaolin were characterized with lower expansion ratio, lower water adsorption, lower elongation at breaking and bending moment in comparison to extrudates produced using native potato starch only. Extruded starch stored in higher moisture showed higher expansion, lower elongation and lower bending moment in comparison to that stored in lower moisture...

The purpose of the work was to determine properties of extruded starch with regard to the adsorption of a cuprum, lead and zinc. Potato starch and its mixture with acetylated starch were subjected to extrusion process in a single screw laboratory Brabender extruder (of 20DN type) at three temperature variants. The extruded starch was stored for 1 hour in distillated water and placed in three different ion solutions containing per 1 litre: A) 0.1 mg Cu, 0.1 mg Pb, 0.1 mg Zn; B) 1 mg Cu, 1 mg Pb, 1 mg Zn; C) 50 mg Cu, 50 mg Pb, 50 mg Zn and then stored again: 1, 5 and 10 days. After the mentioned time, mechanical properties and ions content were determined in prepared samples. The extrudates produced from potato starch at the lowest temperatures exhibited the highest mechanical properties. The addition of acetylated starch and the increase of processing temperature resulted in decrease of product’s mechanical properties...

The aim of the experiment was to assess the chemical and natural methods of potato sprout inhibition. Experiment was carried out on the table potato cultivars: Asterix, Gracja, Finezja, Oman, Wiarus. The tubers were stored at 8°C and treated CIPC and “Talent”. One combination was stored at lower temperature (5°C) with no treatment for sprout inhibition. The assessments were carried out in four periods: from January to June. Mass and length of sprouts, weight losses, diseases were determined. The sprout control of potatoes with treatments of CIPC was very good. The potatoes treated with “Talent” were suppressed like CIPC, with an exception of variety Wiarus which had small sprouts. Potatoes stored at 5°C had smaller sprouts than stored at 8°C. Storage of potatoes at a lower temperature (5°C) significantly reduced the germination in relation to storage at 8oC...

The aim of the study was to describe the influence of meteorological factors during the vegetation period on the occurrence of tuber growth cracks and tuber deformations in the potato yield cultivated in light sandy soil. We conducted an evaluation of the potato cultivars with regard to occurrence of the tubers with these defects. In this study we used data on the share of tubers with growth cracks and tuber deformations in cultivars of different maturity groups. The tubers were collected during the experiments conducted in Potato Agronomy Department IHAR, in 2001–2011. Field trials were performed in light sandy-clay or clay soils. In all tested years, standardized and very similar agrotechnical treatments were applied. That way we could assume that the main source of variance in tuber deformations are the meteorological conditions in each year...

In a field experiment conducted in the years 2006–2011, the influence of potato cultivars and climate conditions on the content of vitamin C and nitrates in tubers and relationships between components were determined. The investigations were carried out in the light soil conditions on 28 table potato cultivars which were divided into three groups: very early and early, mid early, mid late and late. Organic fertilization in the form of straw and aftercrop of white mustard was applied. Mineral fertilization was applied in the doses of 100 kg N∙ha-1; 39.2 kg P∙ha-1; 99.6 kg K∙ha-1. We found significant differences in vitamin C and nitrates content in tubers and relationship between this component for cultivars and weather conditions in years. In most of the tested cultivars, the ratios of vitamin C to nitrates in tubers were advantageous (above 2/1)...

Study on the determination of the effect of liquefying and saccharifying enzyme preparations on the efficiency of the hydrolysis of potato starch at a temperature below the gelatinization temperature. Hydrolysis of starch was carried out using different concentrations of an aqueous suspension of starch, i.e. 5, 10, 20 and 30%, subjected to the enzyme preparations (Liquozyme Supra — liquefying enzyme or Maltogenase 4000 L and AMG 300 L — saccharifying enzymes) that were used individually or in combination during the 24 h of reaction at temperatures of 30, 35, 40 and 45°C. Mass and concentration of the extract, reducing sugars content and yield indicator of hydrolysate were determined in the samples. Studies have shown that raising the reaction temperature from 30 to 45°C during hydrolysis carried out with use of Liquozyme Supra caused almost six-fold increase in the yield indicator of soluble component, i.e. from 2.9 to 17.1%...

The aim of this study was to determine the effect of two potato varieties used in the preparation of French fries, dehydrated potato dice and dehydrated potato (puree) on the acrylamide content in ready product. It was stated that potato tubers of two varieties were of suitable chemical composition, which is required for the production of French fries, dehydrated potato dice and puree. The acrylamide content in processed potato products depended on the used potato variety and the related reducing sugars content in its tubers. Puree prepared from tubers of potato variety Innovator with a lower content of reducing sugars contained 36% lower levels of acrylamide, dehydrated potato — 29% and French fries — 15% less of this compound in comparison with products obtained from potato of variety Santana. Regardless of the potato variety which was used in the study, the lowest acrylamide content was in French fries (349μg·kg-1) and the highest in puree (1156μg·kg-1)...

The field experiment was conducted during years 2010–2011. The phytotoxity reaction of 12 potato cultivars (10 table and 2 starch) to metribuzin was the subject of research. Metribuzin was applied after emergence of potato plants (10 — 15 cm high). The estimation of this reaction and rate of its disappearance was made on the basis of 1-9 scale (1 — resistant plants and 9 — total destruction of plant). Among 12 tested cultivars, only 2 were highly sensitive, 8 — medium sensitive and 2 — low sensitive to metribuzin. Total destruction of plants was not observed for any cultivars...

The aim of this study was to assess changes in total protein content and its yield in potato tubers, depending on nitrogen fertilization, variety, weather conditions, the dry matter and starch content in tubers. Nitrogen fertilization significantly caused significant increase of the protein content and yield. In the range of recommended doses of nitrogen in potato (100–140 kg∙ha-1) protein content was 1,85–1,95;1,72–1,80;1,61–1,68, respectively for early, medium early and late as well as starch varieties. Protein yield depended mainly on the dry matter yield of the tubers. The highest protein yield (over 900 kg∙ha-1)  was achieved by edible cultivar Marlen and two starch cultivars Kuras and Pokusa. We detected a significant negative linear relationship between: protein content and starch content, protein content and dry matter content and a positive correlation between protein yield and dry matter yield of the tubers. Growing season with large amounts of rainfall (2010) reduced the total protein content in comparison with the more arid periods (2006, 2008)...

In this study, we conducted an enzymatic esterification of low acetylated starch by fatty acid using enzymes in an organic solvent. We analyzed both the starting materials and reaction products formed in the esterification. The reaction of esterification using lipase from Candida antarctica and two separate enzyme fractions (A and B) formed three acetylated starch esters of oleic acid. The degree of substitution determined by 1HNMR spectrum analysis ranged from 0.07 to 0.12, and was dependent on the applied fraction of the enzyme. Thermal analysis using differential scanning calorimeter showed that the products’ heats of phase transition were higher than the acetylated starch heat of phase transition. A degree of substitution of acetylated starch had a significant impact on the physical properties of investigated compounds...

The aim of the experiment was the production of new preparations from the mixtures of dried potato pulp and starch by extrusion method and to investigate their properties. Dried potato pulp and starch were mixed in the quantities of 10, 20 and 30%. The mixtures, moistened up to 24%, became subjected to extrusion process within three different temperature variants: 60–70–80°C, 90–100–120°C, 120–130–160°C and the following extrusion parameters: screw rotation speed 180 min-1, batcher rotation 30 min-1, die diameter 3 mm and screw pressure 2:1 were used. The mechanical properties (maximal force acting on the produced preparations, work necessary for their cutting) of obtained extrudates were defined. We determined also solubility, measured in the temperature of 80°C and dietary fibre content of crushed extrudates. We obtained 12 preparations differing in their properties...

The aim of this study was to assess the impact of the size of seed potatoes and their planting density on yield and its structure. We investigated the following six varieties of potatoes: Agnes, Asterix, Denar, Fresco, Innovator and Typhoon. All varieties except Agnes, were planted in two stages of qualification. Seed potatoes differed in size, therefore, we adjusted recommended planting density for them. We assessed: the weight of the tuber, the number of eyes per tuber, number of shoots growing from one tuber and on the surface of 1 ha as well as the average weight of one shoot and on the surface of 1 ha, the yield of potatoes and the structure of harvested crop. A significant positive correlations were found between: the number of eyes on the mother tuber and the average weight of single tuber, shoot weight, the total yield; tuber weight and number of shoots; shoot number and shoot weight and yield...

The aim of this study was a qualitative analysis of potato tubers offered by the holding engaged in the cultivation of varieties for the French fries produced in the company "FRITAR". The study involved four varieties of potato (Agnes, Asterix, Fresco and Innovator), the quality of which was assessed on the basis of the receipt minutes made when the material was received by the processor. The study addressed the following tubers parameters: the dry weight, yield structure, taking into account two dimensions (length and width of the tuber), the share of green tubers, share of tubers with dry and wet rot, mechanically damaged, infested by scab, wilted, sprouted, deformed, damaged by pests, with internal defects, of a size less than 35 mm in diameter of the transverse part  and the amount of mineral impurities. Rating of the tubers targeted for processing into potato chips showed that the cultivars total contribution of external and internal defects has not been exceeded...

The aim the of this study was to demonstrate the effect of the temperature during the collection and loading to the storage, time of day and phase in the technological flow on the mechanical damage index value. The study was conducted in two consecutive years for 22 varieties of potatoes. Potatoes were harvested in the periods: 11.09–23.10.2010 and 22.08–19.10.2011 (a period from 22.08 to 23.10 was divided into seven periods with 10 days interval). The collection took place during the whole day, divided into 12 two-hour time slots and on the set during the day (from 8.00 to 20.00 hours) and night. The temperature at harvest ranged from 4 to 27°C. Scope of work included examination of the extent of damage at different stages of potato harvesting and loading (5 points: separating belt of the harvester, trailer, trash chute, separating belt of the sorter, pile or box pallet) in a single-stage harvest technology with the use of the combine GRIMME SE — 170...

The aim of research conducted in 2010–2011 was to compare the chemical protection against potato late blight conducted in an intensive system, and by a decision support system (DSS) NegFry. Research was carried out in the field of production in Przytocko (north part of Poland) for mid-early, table potato variety Asterix. The following variants of protection against Phytophthora infestans were compared: intensive (chemical protection starts at the beginning of closing the plant in a row, the application of fungicides every 5–10 days); according to DSS NegFry (the beginning of chemical protection, and the next application deadline according to calculations of DSS) and control (no protection against potato late blight). The intensive variant in 2010 consisted of 11 fungicide applications and in the year 2011 — 9 treatments. In the field, where we conducted chemical protection by decision support system NegFry in both research years 6 treatments were performed...

There are 59 fungicides available for potato protection against the most dangerous pathogens: Phytophthora infestans and Alternaria spp. altogether. 58 of them have application in protection against late blight. The ranges of use of 28 fungicides include protection against early blight. Plant protection products placed on the market contain 22 different active substances and lots of them have various modes of action. The number of active substances and plant protection products hasn’t changed a lot comparing year 2012 with 2001. Some of substances and plant protection products used before Poland’s accession to European Union were withdrawn. Some  substances new in potato protection were registered after this time. Some of active substances available on the Polish market are in high resistance risk groups. Plant protection products containing active substances with a risk of resistance usually contain also other substance with different mode of action, what is an important element of resistance prevention strategy...

In the years 2008–2011, in the Department of Potato Protection and Seed Science in Bonin, we carried out a series of laboratory tests assessing the levels of resistance to: tuber wet rot, dry rot and late blight of potato tubers of 25 chosen potato cultivars, registered in 2005–2008. In the conducted tests we did not find varieties resistant at the same time to all evaluated diseases. Among the tested varieties, the most were resistant to tuber dry rot and only few to potato late blight. Among the varieties tested in the group of very early and early, Annabelle showed a low susceptibility to wet and dry rot, and sensitivity to the potato late blight. Medium early variety Agnes was sensitive to wet and dry rot, and weakly susceptible to P. infestans and late variety Niagara turned out to be susceptible to dry rot and potato late blight...

Straight cut and crinkle cut frozen French fries produced by Aviko and McCain were prepared for consumption using an electric oven, a microwave oven and a deep fryer. Their aroma was profiled in the study. The sensory evaluation was performed according to PN-ISO 6564 by a well-trained professional panel of 6 experts. The intensity of particular aroma descriptors was evaluated by the use of a 100 millimeter non-structural graphic scale. The results were subjected to statistic calculation using the method of variance analysis. The heat treatment methods using an electric oven and a microwave oven produced French fries with a characteristic aroma of roasted potato and it was significantly higher (α = 0,01) than in French fries prepared in a deep fryer. The predominant aroma profiles of French fries prepared in a deep fryer were those of potato and fried potato...

The aim of the study was to establish the influence of different heat treatment methods used for frozen potato French fries on their flavour profiles. The material for this study were straight cut and crinkle cut French fries produced by Aviko and Mc’Cain. The fries were prepared for consumption according to the instruction on the packaging by the use of an electric oven, a microwave oven and a deep fryer. The sensory evaluation was performed according to PN-ISO 6564 by a well-trained professional panel of 6 experts. The intensity of particular flavour descriptors was evaluated by the use of a 100 millimeter non-structural graphic scale and subjected to statistic calculation using the method of variation analysis. Preparation of French fries in the microwave oven produced typical flavour of boiled potato, which differentiated them significantly (α = 0.05) from the French fries reheated in the electric oven and deep fryer. The hot oil of the deep fryer proved to be the best heating medium contributing to the emergence of characteristic flavour of fried potato and a fatty nut-like (α = 0.01)...

The aim of this study was to investigate the quality and the technological value of market fresh potato flakes from five manufacturers: Farm Frites Poland in Lębork, Solan S.A. in Głowno, ZPZ „Stolon” in Słupsk, Hügli Food Polska Sp. z o.o. in Łódź and PPZ Sp. z o.o. in Bronisław. Physicochemical properties, moisture content, reducing and total sugars, hydroxymethylfurfural (HMF) and free starch contents were determined in the potato flakes. The sensory evaluation of potato flakes and purée was performed in chair’s sensory analysis lab. It was found that the potato flakes from different manufacturers have different bulk weight (164.56–501.94 g/dm3) and also moisture (7.74–9.97%). The potato flakes had varying but high content of reducing (0.58–5.35%) and total sugars (1.32–5.95%). When the content of sugars in dried potato is too high it’s difficult to use it in production of snacks like crisps or others. The content of free starch (blue value) ranged from 1.21 to 4.04 g/100g...

Field experiments were conducted in 2009–2011 in the north of Poland (Bonin near Koszalin). Productive and qualitative effects of foliar fertilization of potato cv. Jelly with fertilizers YaraVita Ziemniak (P2O5 — 44%, K2O — 7.5%, MgO — 6.7%, Mn i Zn) and Actisil (Si — 0.6%) were evaluated. The best weather conditions for yield were in the years 2009 and 2011 when the yield was over 600 dtha-1, while in 2010 the yield did not exceed 400 dtha-1. Application of foliar fertilizers had no additional yield-forming effect. We found a significant effect on the reduction of the fraction of smallest tubers in the yield by about 50% and an increased share of the largest tubers (over 60 mm), especially after treatment with Actisil (+ 23%) alone or in combination with YaraVita Ziemniak (+ 10%). The assessment of yields for the presence of disease on the tubers showed that the application of silicon definitely limited share of tubers with symptoms of soft rot while the number of tubers with black scurf increased...

The aim of the experiment was to study the influence of thermal coagulation of protein in potato juice isolated from tubers of three potato varieties cultivated conventionally and in ecological system on amino acid composition and nutritive value of obtained preparations. A soil fertilizer and copper salt 50 WP as a fungicide were used within ecological system of potato cultivation and in conventional system fertilizing with high doses of NPK, herbicides, insecticides and fungicides were applied. Protein coagulation was performed in juice containing dissolved CaCl2. After suitable hydrolysis of the obtained concentrates, the chemical composition and contents of  18 amino acids were determined in total protein with the use of automatic amino acid analyser. Potato protein concentrates (PPC) obtained from tubers cultivated within ecological system contained more nitrogen compounds and also forms of protein nitrogen than there were found in preparations originating from juice of tubers cultivated conventionally...