No abstract

Climate changes lead to a rise in air temperature, which significantly increases the water needs of plants. Maintaining crop productivity will increasingly require the use of plant irrigation. The aim of this study was to assess the water needs of grapevines cultivated in the western provinces of Poland. The calculations were made on the basis of temperature and precipitation measurements collected at three meteorological stations in the period 1981–2010. Water needs were calculated as crop evapotranspiration, which was estimated by crop coefficients and reference evapotranspiration, determined using the Blaney–Criddle formula. The rainfall deficit was assessed by Ostromęcki’s method. The tendency to increase the water needs was observed in each subsequent decade of the thirty-year period, both in the whole growing season (May–October), as well as in June–August and July. The highest values of the linear correlation coefficient for the trend of time variability in water needs occurred from June to August. An analysis of water needs and rainfall deficits indicates the need for the additional irrigation of vineyards in western Poland, especially in very dry years and in June–August. Current research results are helpful in designing vineyard irrigation systems and allow an economical and efficient planning of grapevine irrigation.

The aim of this study was to estimate the correlation between heterosis in carrot hybrids and the genetic distances of their parents. The experimental material consisted of 15 inbred lines and 34 hybrids. The yield traits (total and marketable yield), as well as quality characters (carotenes, dry matter, total sugar, monosaccharides and nitrates), were evaluated. Heterosis was computed using two measurements of mid-and high-parent heterosis. Genetic distances among lines were calculated using the RAPD and AFLP techniques. Significant heterosis was found for both total and marketable yield. The content of quality compounds for hybrids usually had mid-parent values. Significant correlations were found between molecular distances among lines, measured using RAPD markers, and heterosis of crosses for total yield, and among divergences of parents measured using AFLP markers and heterosis for marketable yield. This appears to contribute towards the carrot hybrid yield prediction by estimation of the genetic distances between parents. This research was undertaken because the possibility of heterosis prediction would allow for the reduction of costs and quicker identification of superior carrot hybrids.

The purpose of this research was to determine the water needs and results of drip irrigation of mid-early potato cultivar Courage. Studies were carried out in central Poland in 2011–2013 on very light soil. The experiment was designed as two-factorial trials with four replications. The first factor was drip irrigation: O = control (without irrigation), D = drip irrigation. The second factor was the nitrogen fertilization method: P = broadcasting, F = drip fertigation. Nitrogen fertilization was 120 kg N ha−1 on each plot. Crop coefficients for irrigation period were 0.4 in June and 0.6 in July and August. According to calculations based on the crop coefficients and correction coefficients acc. HargreavesDA model the water requirement of potato for June–August was 202 mm. Drip irrigation increased the marketable tuber yield by 55%. Irrigation water use efficiency increased from 257 kg ha−1 mm−1 in D + P to 264 kg ha−1 mm−1 in D + F. The productivity of 1 kg of nitrogen fertilization was 189 kg ha−1 in control non-irrigated plots and 321 kg ha−1 in drip-irrigated plots, and it rose up to 337 kg ha−1 when fertilization was applied by fertigation.

Four inbred lines of carrot (cytoplasmic male‐steriles and corresponding maintainers) and eight of their F1 hybrids were studied with the amplified fragment length polymorphism (AFLP) technique to examine their genetic relationship and produce markers useful for testing hybrid seed purity. Eighty‐six polymorphic amplicons were identified in bulked DNA samples using eight primer pair combinations. Genetic distance was estimated on the basis of the presence or absence of polymorphic bands. The dendrogram plotted on the basis of the AFLP data closely represented the pedigree relationships of the lines and their hybrids. From one to six amplicons specific for a breeding line were identified. Most of them were also present in the DNA bulks of respective F1 hybrids. However, screening performed on individual plants of two parental lines and the corresponding hybrid indicated insufficient uniformity of parental lines, limiting the applicability of AFLP markers for testing hybrid seed purity.

Climate warming increases the water needs of plants. The aim of this study was to estimate the water needs of grapevines in central Poland. Water needs were calculated using the crop coefficients method. Reference evapotranspiration was assessed by the Blaney–Criddle’s equation, modified for climate conditions in Poland. Crop coefficients were assumed according to the Doorenbos and Pruitt method. Water needs were calculated using the data from four meteorological stations. Rainfall deficit with the probability occurrence of normal years, medium dry years, and very dry years was determined by the Ostromęcki’s method. Water needs of grapevines during the average growing season were estimated at 438 mm. Upward time trend in the water needs both in the period of May–October and June–August was estimated. Temporal variability in the water needs was significant for all of the provinces. These changes were mainly impacted by a significant increasing tendency in mean air temperature and less by precipitation totals that did not show a clear changing tendency. Due to climate change, vineyards will require irrigation in the near future. The use of resource-efficient irrigation requires a precise estimate of the grapevines’ water needs. The study identified the water requirements for grapevines in central Poland.

Abstract. Elderberry (Sambucusnigra L.) is a common species belonging to the Adoxaceae family native to most of Europe and North America. For centuries, elderberry has been used as a medicinal plant. This species is also a popular ornamental plant often grown in the gardens and city parks. However, the seedling survival rate of elderberry depends mainly on the suitable soil water conditions that can be controlled using a properly designed and operated microirrigation system. Firstly, it is necessary to determine the water needs of Sambucusnigra L., especially in the first period of growth, which determines the seedling survival rate of the plants introduced into the gardens or parks. A commonly accepted measure of the plant water requirements is the potential evapotranspiration of this plant. The purpose of the research was to assess the water needs of Sambucusnigra L. during the first three years of its growing in five different regions of Poland. Potential evapotranspiration of the elderberry was calculated using modified by Żakowicz for Polish conditions the Blaney-Criddle's method, to which the crop coefficients were adjusted. The study was carried out for thirty years, from 1981 to 2010, in five different agro-climatic regions of Poland.The largest water needs in the period of increased demand for water in elderberry (June-July) occurred in the central-north-western (232 mm) and central-eastern (230 mm) regions. The lowest water needs were found in the south-eastern region (214 mm). The highest rainfall deficit in the central-north-west region (102 mm), smaller rainfall deficit in the central-eastern and south-western regions, amounted to 82 mm and 72 mm, respectively. The lowest rainfall deficit (40 mm) was found in the south-eastern region.In the central-north-west and central-eastern regions, precipitation deficiency occurred in 28 out of 30 considered years (93 % years). In the south-eastern region, precipitation deficiency occurred in 21 years (70 % of years).Keywords : irrigation, evapotranspiration, reclamation, seedling survival, water requirements. IntroductionElderberry (also called medicinal lilac) is a popular plant used for centuries for medicinal purposes [1; 2]. Sometimes it is cultivated -as an ornamental shrub -also in parks and home gardens. High Elderberry planting -on the surface of the park or within a given garden -depends primarily on optimal water conditions that can be effectively shaped using properly programmed and operated microirrigation. However, this requires the necessary prior determination of the needs of water plants, especially in the first -decisive for the success of the plantings carried out -the period of growth of plants introduced into the area of a given park or garden.The objective of the present research was to estimate of the water needs of elderberry (Sambucusnigra L.) at the first three years of growing on reclaimed land in different regions of Poland.

The purpose of this research was to investigate the combining ability of inbred lines in terms of traits important for the development of hybrid carrot cultivars with high yields and better root quality. The experimental plant material consisted of 15 inbred lines that were crossed in an incomplete diallel design to produce 34 hybrids. It was observed that the variation of general combining ability (GCA), specific combining ability (SCA) and reciprocal effects (RE) were significant for all of the tested characters, except SCA for sugars. Among the tested lines, the RFO had the most positive GCA for the yield; at the some time, the RFO line had negative GCA for carotenes and dry matter content. A significant positive GCA was found for all traits, except monosaccharides and nitrates, for the 2163 line. Most of the crosses based on the RFO and 2163 lines yielded well; additionally, the hybrids based on 2163 presented high levels of quality characters. The ratio of GCA:SCA indicated that the quality traits were mainly affected by additive gene effects, but the yield was controlled more by non-additive gene effects. Heritability in a broad sense presented a higher environmental influence for yield than the quality characters of carrot roots.