Quality of kohlrabi stems (Brassica oleracea var. gongylodes L.) kept in cold storage
Two green kohlrabi cultivars, ‘White Delikates’ and ‘Korist’ F1, were kept in cold storage at a temperature of 2°C and a relative humidity of 95%. Natural mass losses were measured at monthly intervals and dry matter content, soluble sugars, L-ascorbic acid and isothiocyanates were analysed. During five months of storage, very low losses of kohlrabi mass were detected. The decrease in dry matter during that time was between 15 and 18%. After a brief increase, soluble sugar content decreased during storage, and in March, 50% of the initial sugar content was calculated for ‘Delikates’ kohlrabi flesh and 65% for ‘Korist’. L-ascorbic acid was well preserved in the kohlrabi, since 90% remained after storage was completed. The isothiocyanate content changed little and the vegetable remained a good source of these compounds throughout the storage period.
Evaluation of the quality of 15 cultivars of red beet has been made during four successive vegetative seasons. The study involved cultivars ‘Astar F1’, ‘Boro F1’, ‘Ceryl’, ‘Chrobry’, ‘Czerwona Kula’, ‘Egipski’, ‘Karmazyn’, ‘Nabab F1’, ‘Nochowski’, ‘Opolski’, ‘Pablo F1’, ‘Patryk’, ‘Regulski Cylinder’, ‘Okrągły Regulski’ and ‘Rywal’. The mass, diameter of roots, antioxidant activity, the content of dry mass, soluble sugars, betanin and vulgaxanthin in roots were evaluated. The study indicated ‘Chrobry’ as the cultivar of the most favorable quality features. It was characterized by high antioxidant activity, high content of dry mass, soluble sugars and betalain pigments. Among cultivars of cylindrical shaped roots, content of soluble sugars and antiradical activity was the highest in ‘Regulski Cylinder’ roots.
The experiment on different means of cultivation of red beet cv. ‘Regulski Cylinder’ was conducted in the years 2006-2009, using conventional, integrated, and organic methods. The greatest impact on total and commercial yield, the average root weight, dry weight and chemical constituents’ content in the roots had the season. In the years 2006 and 2008, the highest total and marketable yields of beet roots were obtained by organic method, but in 2009 these parameters were the lowest in organically produced plants. Total yield was correlated with mean root weight. In the years 2006 and 2008, betanine content was the lowest in organically produced roots while in the year 2009 it was the highest. The low yield of marketable roots and the low nitrates’ content were the only two parameters, which distinguished organically produced red beet roots throughout the years of experiment.
Beetroot is a vegetable that accumulate heavy metals. This is largely dependent on the cultivar, methods and growing conditions. The aim of the study was to determine the composition of elements in the roots of 15 cultivars of red beet. The analysis assessed the content of macroelements (Na, P) and heavy metals (Cd, Cr, Mn, Zn). Most soils of the Lesser Poland region are exposed to the impact of industrial and transportation pollution. The soils of this region are characterized by strong acidification as well as natural or increased heavy metal content. The experiment was set up at the experimental field of the Department of Vegetable and Medicinal Plants of the University of Agriculture in Krakow, in 2009-2010. On the basis of the performed analysis, ‘Opolski’ was chosen as the cultivar that was characterized by a high content of macroelements and lower ability to accumulate heavy metals than the other tested cultivars. The lowest ability to accumulate heavy metals (Cd and Cr) was found in the cases of cultivars with cylindrical root shapes, such as Rywal or Opolski. One can indicate such cultivars as Astar F1 or Nabab F1 as cultivars recommended for cultivation in ecologically threatened areas.
Red beet (Beta vulgaris L.) may be consumed at all stages of growth, both in the form of small early vegetable during spring and later, during winter, when stored. Therefore, knowledge of the dynamics of changes in the content of individual components in subsequent stages of growth is very important.
The experiment was conducted for two consecutive growing seasons. The study included four cultivars of red beet ‘Boro’ F1, ‘Czerwona Kula’, ‘Nochowski’ and ‘Regulski Cylinder’. The aim of this study was to assess the dynamics of changes of selected components during the growing season. Particular attention was paid to the content of components having a positive impact on the quality of red beet, such as: antioxidant activity, the content of betalain pigments, soluble sugars and dry matter.
On the basis of the survey it was demonstrated that the optimal harvest date of red beet roots, with respect to the favorable nutrient and health-related content, falls in the 8th and 11th week of the growing season depending on the weather conditions in a given year. A significant increase in the anti-radical activity, soluble sugars as well as betanin and vulgaxanthin (2009) was observed between the 6th and the 8th and also in the 11th week of the cultivation. A gradual drop in betanin to vulgaxanthin ratio was observed within the following weeks of the vegetation. On the basis of the research conducted we can conclude that the cultivar recommended for consumption is ‘Nochowski’.
Elżbieta Jędrszczyk, Barbara Skowera, Maria Gawęda and Andrzej Libik
Cultivation of field tomato in Poland meets unfavorable temperature and precipitation conditions, which affect yield and quality. The aim of the study is to evaluate the effect of temperature and precipitation conditions on the growth and development dynamics of five cultivars of processing tomato. The analysis took into account the key morphological characteristics of the plant, the inflorescence and fruit, which determine the suitability of the cultivar for processing. Analysis of the effect of meteorological elements on the stem development showed that stem length was most strongly influenced by precipitation – both total precipitation and frequency, rather than by temperature; the greater the rainfall, the more intensive stem elongation. High levels of precipitation limited gains in stem thickness. The number of flowers and fruits formed per inflorescence was negatively correlated with temperature. Excessive precipitation during the entire growing period led to formation of smaller fruits. The length and width of the fruit were negatively correlated with the frequency of precipitation in all stages, and with total precipitation during the period from planting to setting of the first fruits. A beneficial effect of temperature on the length and width of the fruit was noted during the entire growing period. The tomato fruit formed a thicker pericarp when precipitation was more frequent.
Elżbieta Jędrszczyk, Barbara Skowera, Renata Kędzior and Maria Gawęda
The aim of the study was to evaluate the effect of ethephon application (Agrostym 480 SL) on the yield and yield structure of five processing tomato cultivars (Rumba, Hubal, Sokal F1 , Mieszko F1 and Polset F1 ). The experiment was carried out in the open field in the years 2009-2011 in Mydlniki near Kraków, Poland. Two weeks before harvesting, half of the plants of each cultivar were treated with Agrostym 480 SL (3 dm3 ha-1) and the other half were left as a control without spraying. Marketable yield included properly shaped and welldeveloped light red and red fruits. Non-marketable yield included pink and turning fruits, mature green and breaker fruits, and diseased fruits. A generalized linear model (GLM) for Poisson distribution with the log link function was used to determine the relationship between the years of the study and cultivar and selected values of the yield structure. The yield structure of tomato depended significantly on the weather conditions during the growing period in different years of the study, on the cultivar, and on the use of ethephon. Ethephon had a particularly beneficial effect on yield structure in the years with an unfavourable distribution of precipitation. Ethephon application in the years 2009 and 2010 had a beneficial effect on the health of tomato plants.