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Tijskens L.M.M.,Wageningen University | Schouten R.E.,Wageningen University | Konopacki P.J.,Institute of Pomology and Floriculture | Hribar J.,University of Ljubljana | Simcic M.,University of Ljubljana
Journal of the Science of Food and Agriculture | Year: 2010

Background: The yellow aspect of colour is usually not considered for produce with a green-to-red or a green-to-yellow transition upon ripening. The magnitude of change is simply too small and, additionally, masked by a large variation. The colour of 'Granny Smith' apples, harvested from three orchards at two stages of maturity, was measured individually using the CIE L* a* b* system during storage in a regular atmosphere at three temperatures: 1, 4 and 10°C. A model was developed based on a simplified mechanism, consisting of two consecutive reactions, to describe the development of the apple colour expressed as b* and L* values during storage. Results: Monitoring individual apples made it possible to include and describe the biological variance of colour in batches of apples and to extract information on chilling injury, as a process active at 1 °C. All variations could be attributed to a single source related to the amount of yellowing compounds at the moment of harvest, indicating differences in state of maturity between individual apples. The obtained explained part (R2adj), using nonlinear mixed effects regression analysis was well over 90% for all data combined over more than 3000 observations. Conclusion: Orchardlocation hadaslight effect on themean initialcolour value, indicating differences in development stage, most probably due to differences in assessing the harvest date. The magnitude of the variation in these colour values was, however, the same for all three orchards. The behaviour of the green colour aspect (a* value) has been reported separately, as this represents the major change in perceived colour. The changes in b* and L* values are rather small, while the biological variation between the individual fruit is at least of the same magnitude. The model presented here is, as far as known, the first model on b* and L* values for green-coloured products. Analysing b* and L* data using this model provides additional informationwith respect tothestageofmaturityatharvestin a batch or for an orchardofGrannySmithapples. Allthevariation in the yellow colour aspects could be attributed exclusively to the initial level of yellow compounds. © 2010 Society of Chemical Industry.


Stepien W.,Warsaw University of Life Sciences | Stepien T.,Research Institute of Horticulture | Kozinski B.,Research Institute of Horticulture | Smolarz K.,Institute of Pomology and Floriculture
Acta Horticulturae | Year: 2014

Since 1923 a long-term fertilization experiment has been carried out in one of the fields of the Experimental Station of the Warsaw Agricultural University in Skierniewice. Until now, this field has not been fertilized with organic fertilizers and no legumes have been grown there. Mineral CaNPK fertilizers have been applied each year according to the following scheme: O, CaNPK, NPK, PK, PN, KN. Since 1976, 90 kg N/ha in the form of (NH4) 2SO4, 60 kg P2O5 in the form of Ca(H2PO4)2 and 110 kg K2O in the form of KCI has been applied. The experiment with highbush blueberry was set up in 1976 and carried out in 3 replications with 9 plants of each cultivar per plot. This paper presents growth and fruit yield of the blueberry plants in three periods: the first one from 1976 till 1988, the second one till 2005 and the third one till 2011. In the third period of the experiment, the rejuvenation pruning was additionally introduced by cutting back the plants at various heights. The greatest negative influence on yielding of blueberry plants was obtained from plants with liming plots (CaNPK) and without nitrogen fertilization (PK). The blueberry plants reaction to potassium fertilization was very weak. Despite of the low K content in the PN combination, the yield was only about 10% lower than in the NPK combination. On the plots without phosphorus fertilization, the yield was similar to that obtained from the plots fertilized with this component. The annual fertilization with P and K increased the levels of these components in the leaves, while liming increased the levels of Ca and Mg and decreased those of Fe, Zn and Mn.


Smolarz K.,Institute of Pomology and Floriculture | Kozinski B.,Research Institute of Horticulture
Acta Horticulturae | Year: 2014

New trials on cranberry experimental production were recently performed at the Research Institute of Pomology and Floriculture in Skierniewice. The first results are presented here.


Kurek E.,Maria Curie Sklodowska University | Ozimek E.,Maria Curie Sklodowska University | Sobiczewski P.,Institute of Pomology and Floriculture | Slomka A.,Maria Curie Sklodowska University | Jaroszuk-Scisel J.,Maria Curie Sklodowska University
Scientia Horticulturae | Year: 2013

The use of phosphate solubilizing bacteria as inoculants may increase the concentration of plant-available phosphorus in soil. Among soil microorganisms, bacteria from the genus Pseudomonas have received considerable attention as plant growth promoters. A phosphate solubilizing bacterium isolated from non-rhizosphere soil collected in Central Poland, was identified as Pseudomonas luteola BN0834 on the basis of biochemical methods and 16SrDNA sequence analysis. P. luteola strain BN08-34 was tested for: solubilization of inorganic and organic compounds of phosphorus (calcium phosphate, zinc phosphate, hydroxyapatite and calcium phytate); indole acetic acid (IAA), siderophore production and biosurfactant production; and the ability to grow on a medium without nitrogen added. Young apple trees, cultivar Ligol (rootstock M26), were grown in a pot-house for 14 weeks in pots filled with nonsterilized soil, classified as a sandy loam. The P. luteola BN0834 was introduced into the soil in a number equal to the number of native phosphate solubilizing microorganisms (PSM) (P. luteola) in soil or in a number ten times higher than the number of native PSM in soil (P. luteola×. 10). Shoot numbers; average and total shoot lengths; contents of P, K, Mg and Ca in plant material; contents of available P, K and total Mg in non-rhizosphere soil, changes in the number of cfu (colony forming units) of microorganisms (PSM, cophiotrophs, oligotrophs and fungi) in non-rhizosphere soil and in the rhizosphere of the apple trees were studied. When the higher number of P. luteola BN0834 was introduced into soil without a mineral fertilizer added near the surface of the roots, positive correlations were found between the number of PSM in the apple tree rhizosphere and the content of available P in non-rhizosphere soil and also between the number of PSM in the apple tree rhizosphere and the amount of P, K and Ca in plant leaves. The highest total shoot length was also obtained from P. luteola×. 10 application. © 2013 Elsevier B.V.


Szymula J.,National Animal Breeding Center | Skowronek W.,Institute of Pomology and Floriculture | Bienkowska M.,Institute of Pomology and Floriculture
Journal of Apicultural Science | Year: 2010

Morphological traits were evaluated in 289 samples of honeybees (Apis mellifera) belonging to three races: Middle European (A. m. mellifera), Carniolan (A. m. carnica) and Caucasian (A. m. caucasica). The microscope method was used to measure the length of the proboscis, the width of tergite IV and cubital index, while computer analysis was applied to measure 32 traits on the honeybee wing. Discriminant analysis of the results demonstrated that both measuring methods differentiate the races to a similar degree. Out of all traits compared, the greatest discrimination strength was attributed to the length of the proboscis measured with the microscope method. The other traits displayed various discrimination strengths, yet they all contributed to the discrimination of the races. Morphological measurements performed with the microscope method are twice as time-consuming than the respective measurements conducted with the computer method.

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