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Common bean (Phaseolus vulgaris L.) is the most widespread legume in Croatia and its production is based on landraces of great morphological diversity. Landraces morphologically differ the most in the seed coat color and size. Because plant emergence and crop establishment represent the most sensitive stage in crop development, the aim of this study was to determine whether the seed coat color and seed size of Croatian common bean landraces affect the water absorption rate, seed germination, emergence and phenotypic characteristics of the seedlings. In this study seeds of four common bean landraces with different seed color and size, ‘Biser’ (white-colored, small-seeded), ‘Bijeli’ (white-colored, large-seeded), ‘Kornjača’ (dark-colored, small-seeded) and ‘Trešnjevac’ (dark-colored, large-seeded) were evaluated in three different experiments: (i) water uptake, (ii) seed germination and (iii) emergence and seedling phenotypic characterization. The results show that white-colored seeds have a higher absorption rate and release more electrolytes compared to dark-colored seeds of similar size (and weight). The germination results show that white-colored and smaller seeds germinate faster compared to dark-colored and large seeds. On the other hand, the white-colored landrace ‘Bijeli’ took the longest time to emerge, probably due to cell damage that occurred during the fast initial water absorption. Using multispectral imaging, chlorophyll fluorescence imaging and stomatal conductance analysis, the seedlings of the dark-colored and large-seeded landraces were found to contain more photosynthetic pigments and have higher light absorption. In contrast, seedlings of white-colored and large seeds have lower stomatal conductance and transpiration and higher photochemical efficiency (despite possible cell damage during water absorption and germination). Results suggest that dark-colored seeds could survive better under unfavorable soil conditions without absorbing water, swelling, emergence or molding than white-colored seeds. Despite all this, white-colored common bean landraces remain popular in human diets and are often grown on small-scale farms.

U ovome radu prikazani su rezultati rasta bukovih sadnica pod utjecajem suboptimalne ishrane s dušikom (N), fosforom (P), magnezijem (Mg) i željezom (Fe). Cilj rada bio je približiti ovu problematiku šumarskoj praksi kroz raspravu dobivenih rezultata u kontekstu dosadašnjih spoznaja o rastu biljaka pod utjecajem suboptimalne ishrane s mineralnim hranivima. U rano proljeće 2019. godine 30 bukovih jedinki u razvojnom stadiju ponika, porijeklom iz jedne prirodne mješovite sastojine hrasta kitnjaka i obične bukve, presađeno je u sterilni supstrat (agroperlit). Nakon presadnje tijekom sljedeće tri godine po šest presađenih biljaka redovito je zalijevano (tretirano) s kompletnom hranjivom otopinom (KO tretman), odnosno hranivim otopinama u kojima su izostavljeni dušik (-N tretman), fosfor (-P tretman), magnezij (-Mg tretman) ili željezo (-Fe tretman). Prema tomu, na šest biljaka unutar svakog od pet prethodno opisanih tretmana bilježeni su početak i trajanje razvoja lišća (2020. i 2021. godine), broj listova te prosječna i ukupna površina lišća (2019., 2020. i 2021. godina). Promjer stabljike na vratu korijena i visina stabljike mjereni su u proljeće 2019. i jesen 2021. godine, na temelju čega je izračunat debjinski i visinski prirast bukovih sadnica, te njihova vitkost na početku i na kraju pokusa. Uz to, tretiranim sadnicama utvrđena je masa suhe tvari lišća, stabljike i korijenja te ukupna dužina krupnog i sitnog korijenja, kao i broj račvanja i vrhova sitnog korijenja, što je obavljeno u jesen 2021. godine nakon njihova vađenja iz agroperlita. Na temelju usporedbe dobivenih rezultata između biljaka u kontrolnom i ostalim tretmanima bilo je moguće zaključiti da je pod utjecajem suboptimalne ishrane bukovih sadnica s P došlo je do odgode proljetnog otvaranja pupova i početka razvoja lišća. Najsporiji razvoj lišća zabilježen je pod utjecajem suboptimalne ishranjenosti s N i Mg. Prosječna površina lišća nije bila značajnije utjecana suboptimalnom ishranjenošću niti s jednim hranivom. Smanjenje broja listova i njihove ukupne površine pod utjecajem suboptimalne ishranjenosti sa svim hranivima zabilježeno je tek u posljednjoj godini provedbe pokusa. Debljinski i visinski prirast stabljike također su bili negativno utjecani suboptimalnom ishranjenošću sa svim hranivima, a smanjena vitkosti sadnica zabilježena je samo pod utjecajem suboptimalne ishranjenosti s Fe. Ukupna, duljina krupnog i sitnog korijenja također je bila negativno utjecana suboptimalnom ishranjenošću sa svim hranivima, izuzev N. Pod utjecajem suboptimalne ishranjenosti s N došlo je do povećanja ukupne dužine sitnoga korijenja, kao i do povećanja broja račvanja i vrhova sitnog korijenja. Unatoč tomu, na masu suhe tvari krupnog i sitnog korijenja suboptimalna ishranjenost sa svim hranivima imala je negativan utjecaj, uključujući i N.

Common bean (Phaseolus vulgaris L.) is a plant with high nutritional value that occupies an important place in human nutrition worldwide. Its yields vary widely and are often below the genetic potential of the species, given the diversity of cropping systems and climatic changes. Common bean landraces are a source of great genetic variability and provide excellent material for the selection and improvement of numerous agronomic traits and the creation of modern cultivars. It is also important to use high quality seed of high-yielding cultivars in production, because in common bean, in addition to yield and resistance to abiotic and biotic stress factors, traits such as nutritional value and digestibility are also the focus of interest. The success of common bean production depends to a large extent on the quality of the seed, the production approach and new breeding programs.

Drought negatively affects plants by altering morphological, physiological and metabolic processes and ultimately reducing yields. Garlic (Allium sativum L.), an important member of the Alliaceae family, is also sensitive to drought and maximizing the yield of garlic bulbs is largely dependent on water availability. The objective of this study was to determine the effects of drought stress on morphological and physiological characteristics, as well as on phenolic, sugar, inulin and free amino acid content and antioxidant activity in two Croatian garlic ecotypes, ‘Istarski crveni’ (IC) and Istarski bijeli (IB). Drought was induced by using polyethylene glycol 8000 (PEG) solution (−0.6 MPa) starting 21 days after clove planting and lasted for 20 days. Drought reduced plant height, number of leaves and plant weight, but increased root length in both ecotypes compared to the control treatment. Among the physiological parameters, significant differences were observed between the two ecotypes studied in the spectral characteristics of the leaves, namely reflection in red, green and blue, VAL, values of the vegetation indices related to the chlorophyll content (CHI, GI), and the anthocyanin content (ARI). Ecotype IC showed higher antioxidant activity in the control treatment due to higher total phenolic content (TPC), but under drought conditions higher DPPH radical scavenging activity was determined in ecotype IB and higher values of FRAP in IC. Sucrose and glucose generally decreased under drought, while inulin increased in IB but decreased in IC. Total free amino acid content increased under drought in both ecotypes. In conclusion, drought tolerance of IB might be associated with increased accumulation of inulin and higher levels of amino acids, especially those shown to contribute to drought resistance. In IC, drought tolerance is associated with an increase in some amino acid compounds and better root growth in depth, probably due to a more efficient translocation of sucrose to the underground part of the plant.

The effects of light on plants depend on the energy dose and spectral characteristics. We investigated how UV-A radiation with two different wavelengths, 365 and 385 nm, combined at different intensities as supplemental light to red-blue baseline illumination affects growth and selected physiological and biochemical traits of green leaf basil (Ocimum basilicum L.). Conventional physiological measurements and biochemical analyses of photosynthetic pigments and phenolics were combined with high-throughput phenotyping. We did not detect any negative effects of UV-A on plant growth and photosynthetic functions, even at high doses of short-wave UV-A. Furthermore, thylakoid processes were enhanced under UV-A, as evidenced by higher electron transport rates and increased photochemical efficiency. The increase in anthocyanin index (ARI) indicates the UV- screening response. However, no anthocyanins were detected in the leaves, and the only phenolic compounds that responded to UV-A were hydroxycinnamic acid derivatives, which have a dual function in responding to UV-A (UV protection and antioxidants). UV-A increased the pool of xanthophyll cycle pigments and their ratio to chlorophylls. All this prevents photoinhibition and contributes to a high plasticity/efficiency of the basil's response to light environment.

Potato (Solanum tuberosum L.) is vulnerable to high temperatures, which are expected to increase in frequency and duration due to climate change. Nondestructive phenotyping techniques represent a promising technology for helping the adaptation of agriculture to climate change. In this study, three potato cultivars (Agria, Bellarosa and Desiree) were grown under four temperature treatments: 20/15 °C (T1), 25/20 °C (T2), 30/25 °C (T3), and 35/30 °C (T4). Multispectral and chlorophyll fluorescence imaging, 3D multispectral scanning, and gas exchange analysis were used to study the effect of moderate heat stress on potato morphology and physiology and select phenotypic traits most responsive to increased temperatures. The most responsive morphological traits to increased temperatures are related to decreased leaf area, which were detected already at T2. Increased temperatures (already T2) also changed leaf spectral characteristics, indicated by increased red, green, and blue reflectance and decreased far-red reflectance and anthocyanin index (ARI). Regarding chlorophyll fluorescence, increasing temperatures (T2) caused an increase in minimal fluorescence of both dark-adapted (F0) and light-adapted (F0’) plants. Stomatal conductance, transpiration rate, photosynthetic rate, instantaneous water use efficiency (WUE), and intrinsic water use efficiency increased from T1 to T3 and decreased again in T4. Using recursive partitioning analysis, the most responsive potato phenotypic traits to increased temperature were leaf area projected (LAP), ARI, F0, and WUE. These traits could be considered marker traits for further studying potato responses to increased temperatures.

Celer je povrće s malom kalorijskom vrijednosti i razmjerno malo vitamina no s brojnim zdravstvenim vrijednostima. Željezo je esencijalni element za biljke i za čovjeka zbog čega je nužno zadovoljiti potrebe njegovog dnevnog unosa oko 8-20 mg/dan. Cilj istraživanja bio je utvrditi količine željeza u korijenu celera korjenaša s obzirom na konvencionalni ili ekološki način poljoprivredne proizvodnje. Uzorci su prikupljeni u gradu Zagrebu u trgovačkim lancima, trgovinama ekološkim proizvodima i tržnici. Nakon razgradnje s koncentriranom HNO3 i HClO4 željezo je određeno pomoću AAS (atomskog apsorpcijskog spektrofotometra). Statistička obrada podataka provedena je prema metodi analize varijance (ANOVA). Količina željeza u suhoj tvari korijena celera korjenaša kretala se od 39,68 do 68,11 mg Fe/kg ST, odnosno od 0,44 do 0,71 mg Fe/100 g svježe tvari., Celery is a vegetable with low calories and low content of vitamins, but has many good benefits on health. Iron is an essential microelement for plants and for humans too. Therefore, it is necessary to satisfy RDA (Recommended Dietary Allowance) uptake of 8-20 mg/day. The goal of present research was to determine the celeriac iron content regarding conventional and ecological agricultural production. Samples were taken in city of Zagreb in chain stores, stores with organic products and markets. After digestion with concentrated HNO3 and HClO4, iron was determined by AAS (Atomic Absorption Spectroscopy). Statistical data analysis was performed using Analysis of variance method (ANOVA). Iron celeriac content ranged from 39.68 to 68.11 mg Fe/kg DW, and from 0.44 to 0.71 mg Fe/100 g fresh weight.

Basil is one of the most widespread aromatic and medicinal plants, which is often grown in drought- and salinity-prone regions. Often co-occurrence of drought and salinity stresses in agroecosystems and similarities of symptoms which they cause on plants complicates the differentiation among them. Development of automated phenotyping techniques with integrative and simultaneous quantification of multiple morphological and physiological traits enables early detection and quantification of different stresses on a whole plant basis. In this study, we have used different phenotyping techniques including chlorophyll fluorescence imaging, multispectral imaging, and 3D multispectral scanning, aiming to quantify changes in basil phenotypic traits under early and prolonged drought and salinity stress and to determine traits which could differentiate among drought and salinity stressed basil plants. Ocimum basilicum “Genovese” was grown in a growth chamber under well-watered control [45–50% volumetric water content (VWC)], moderate salinity stress (100 mM NaCl), severe salinity stress (200 mM NaCl), moderate drought stress (25–30% VWC), and severe drought stress (15–20% VWC). Phenotypic traits were measured for 3 weeks in 7-day intervals. Automated phenotyping techniques were able to detect basil responses to early and prolonged salinity and drought stress. In addition, several phenotypic traits were able to differentiate among salinity and drought. At early stages, low anthocyanin index (ARI), chlorophyll index (CHI), and hue (HUE2D), and higher reflectance in red (RRed), reflectance in green (RGreen), and leaf inclination (LINC) indicated drought stress. At later stress stages, maximum fluorescence (Fm), HUE2D, normalized difference vegetation index (NDVI), and LINC contribute the most to the differentiation among drought and non-stressed as well as among drought and salinity stressed plants. ARI and electron transport rate (ETR) were best for differentiation of salinity stressed plants from non-stressed plants both at early and prolonged stress.

Common bean (Phaseolus vulgaris L.) exhibits a wide range of seed coat colors and this morphological trait is widely used in cultivar identification and assessment of diversity within this species. With an advancement in technology and informatics, new methods of assessing seed color are emerging in addition to traditionally used visual observation. Due to a great variety of color measuring techniques, the evaluation of the agreement between methods is needed prior to using the methods interchangeably. Seed coat color in terms of CIE L*a*b* color coordinates of 100 common bean accessions belonging to five mono- colored landraces was assessed using two methods, colorimeter and Computer vision. The percentage difference between the two methods across all samples for L* color coordinate was 5.81%, for a* color coordinate 23.32% and for b* color coordinate 44.44%. According to Bland- Altman difference plot there is a considerable lack of agreement between the two methods. However, using stepwise discriminant analysis revealed that colorimeter method correctly classified 97% of accessions into their respective landrace, while the classification success of the Computer vision was 99%.

Loess-derived sediments represent the most widespread soil parent materials in the Pannonian region of Croatia. Pseudogley, as the most common soil type in this region, developed mainly on such parent materials. Pseudogleys largely correlate with the WRB Reference Soil Group of Stagnosols. On the General Soil Map of Croatia at scale 1: 50 000 (GSM of Croatia), the distinction is made between Pleistocene loams (PL) and loess as Pseudogley parent materials. The initial purpose of this research was to investigate if the criteria for this distinction were clear and consistent and if the terms used for labeling these parent materials were adequate. Hence, we investigated parent materials of 18 Pseudogleys across 6 different locations (three on loess and three on PL) in the Pannonian region of Croatia. We analyzed their morphology (including micromorphology of three representative parent materials), particle size distribution, total porosity, pH, and mineral assemblages (by modal analysis of three representative parent materials). Following these analyses, no systematic differences between the loess parent materials and the PL parent materials were found. Additionally, it was concluded that, due to significant geogenetic and/or pedogenetic alterations of all studied parent materials, none of them should be labeled simply as loess. Hence, parent material at one location was labeled as leached loess derivate, and parent materials at all other locations were labeled as pseudogleyed loess derivates. Both types of parent materials were described in detail and defined. In addition, the terminology and the classification of loess(-derived) parent materials in general was proposed. The analyzed pseudogleyed loess derivates were not completely uniform across the investigated locations. Primarily, this was due to the polygenesis of loess (reflected by differences in particle size distributions and compositions of light and heavy mineral fractions). Secondarily, it was due to the 600–1100 mm MAP gradient along the study region (reflected by differences in pH values and properties of redoximorphic features). Although pedogenesis of the investigated parent materials might have started already during the Late Glacial and have continued throughout the Holocene at varying (and overall decreasing) rates, their morphology indicates that pseudogleization and lessivage are still active processes, which occur simultaneously in the analyzed parent materials and agree with the present climate.

A survey of recently discovered vitiviruses was performed on 113 Croatian autochthonous grapevine cultivars from the national collection “Jazbina” using one-step RT-PCR. The presence of grapevine virus H (GVH) was confirmed in nine (7.9%) cultivars and grapevine virus G in eight (7.1%), while the presence of grapevine viruses I and J were not detected. GVH was transmitted by the vine mealybug (Planococcus ficus) from a source plant to grapevine seedlings with a 10.5% transmission rate using a combination of 10 first and second instars per plant with 48 and 72 h of acquisition and inoculation access period, respectively. Transmission correlated with the presence of grapevine leafroll-associated virus 3 (GLRaV-3) in the GVH-source plant and recipient seedlings. No alternative GVH host was identified. A comparison of 356 nt fragments of the RdRP and CP coding regions showed nucleotide identity between the Croatian GVH isolates in the range of 95.5–99.2% and 97.5–99.4% and amino acid identity between 95.8 and 100% and between 98.3 and 100%, respectively. Comparison with foreign isolates revealed nucleotide sequence similarity in the RdRP and CP between 94 and 100% and between 97.7–100%, respectively. To the best of our knowledge, this is the first report of GVH in Croatia and the first identification of the vine mealybug as a vector of GVH.

Arbuscular mycorrhizas (AM) can improve phosphorus (P) nutrition and could serve as an environmentally friendly approach for sustainable crop production under P-limiting conditions. The objectives of this study were to assess the effect of AM on different physiological traits and to quantify the responsiveness of different basil (Ocimum basilicum L.) cultivars to AM under low P availability. The basil cultivars ‘Genovese’, ‘Sweet Basil’, ‘Dark Opal’, and ‘Erevanskii’ were inoculated (AMI) using Rhizophagus irregularis. Photochemical efficiency and gas exchange were measured on AMI and non-inoculated (AMC) plants and, at harvest, the shoot biomass, shoot P concentration, root morphological traits, frequency of mycorrhizas in the roots (F%), and extent of root colonization (M%) were determined. Significant differences in F% and M% were found among the examined cultivars, with the highest found in ‘Dark Opal‘ and the lowest in ‘Erevanskii‘. AMI reduced the shoot biomass and increased the shoot P concentration as well as other examined root traits in ‘Genovese’ and ‘Erevanskii’, whereas it did not affect those traits in ‘Dark Opal’ and ‘Sweet Basil’, indicating differences in responsiveness to AM. AMI positively affected the gas-exchange parameters in all examined cultivars, probably due to the increased sink capacity of a bigger root system and/or AM structures within the roots.

Stony karst landscape in the Adriatic coastal area has been cultivated for centuries to grow Mediterranean crops. Shallow and less fertile soils were mostly used for rain-fed grapevine and olive production. Native grapevine cultivars are, in general, well adapted to the warm and droughty climate, but a rapid drift in weather patterns characterized mostly by long-lasting high temperature events during the growing season urges the producers to apply irrigation. This research, studying the effects of different irrigation levels on Babic grapevine performance, was carried out in two growing seasons (2015 and 2016) with contrasting weather conditions in a vineyard established on a parcel of land derived from the stony surface of a limestone plateau on the very edge of the Eastern Adriatic coast. The study evaluated the effects of different irrigation regimes based on the quantification of grapevine water use (50, 75, and 100 % of crop evapotranspiration) by measuring the total leaf area, leaf gas exchange performance, and grape yield and quality. The irrigation treatments increased the total leaf area, net photosynthetic rate, average transpiration rate, and average mesophyll CO2 concentration. The yield components and grape quality were also affected by the irrigation treatments. Positive effects of irrigation in both the experimental seasons were associated with increased yield and total soluble solids (TSS), as well as synchronized TSS and phenolic ripening. Furthermore, water stress positively affected the concentrations of anthocyanins and other polyphenols in both years of the study. In 2015, extremely high temperatures reduced the grape yield, juice yield, and anthocyanin content in grapes in non-irrigated vines as well as in all irrigation treatments. Irrigation was efficient in reducing these negative effects, except in the case of the anthocyanin content.

Pseudogley is a soil characterized by vertical texture contrast and periodic stagnation of precipitation water. Its profile is often designated as A-Eg-Btg-Cg. It is the second most frequent soil type in Croatia, found almost exclusively on non-calcareous loess sediments in the Pannonian region of the country. The aim of this research was to determine if differences in particle size distribution and basic chemical properties exist among Pseudogleys formed along the 600–1100 mm mean annual precipitation (MAP) gradient on two different relief positions (plateau and slope) across the Pannonian region of Croatia. A total of 33 soil pits were dug in natural forests. The trends observed with soil depth for particle size distribution, organic C content, pH, Ca2 +/Mg2 + ratio, and base saturation point to the predominance of top-down formation of the investigated soil profiles. Both relief and climate influenced the distribution of Pseudogleys across the Pannonian region of Croatia. The incomplete homogeneity of loess parent materials across the study region governs the variations in clay content, silt content, and cation exchange capacity among the investigated Pseudogleys. Conversely, the increase in MAP along the investigated transect caused a decrease in soil pH, base saturation, and Ca2 +/Mg2 + ratio, and the increase in organic C content along the investigated profiles. Therefore, future studies of climate impact on loess-derived soils in this region should take into account only soil chemical properties that are not directly dependent on particle size distribution. The relief position on which soil pits were situated had no effect on soil characteristics. Hence, it seems that Pseudogleys should not be systemized according to their position on plateau or on slope, as it is the case in some classification systems.

The long tradition of common bean (Phaseolus vulgaris L.) cultivation in Croatia has resulted in the development of many landraces, which create a valuable basis for screening different physiological traits. Studying gas exchange parameters could provide valuable information that could be useful in creating new crop germplasm with enhanced agronomic attributes. Variability of gas exchange parameters, such as the net photosynthetic rate (A), transpiration rate (E), stomatal conductance (gs), intercellular CO2 concentration (Ci), light use efficiency (LUE), and water use efficiency (WUE) were studied on the collection of 226 common bean accessions and the relationship of the gas exchange parameters with the origin and morphological traits was tested. The highest variability among all landraces was found for the WUE and gs, and lowest for the A and LUE traits, indicating high potential of these traits to be used for selection and breeding programs. Accessions of the Mesoamerican origin had higher A and LUE and lower Ci values compared to accessions of the Andean origin. Accessions with the determinate growth had higher gs and Ci values and lower A, LUE and WUE values compared to accessions with the indeterminate growth. The variance components analysis showed that the growth type has a more pronounced effect on gs, Ci and WUE, whereas the origin has a stronger impact on A and LUE. The principal component analysis (PCA) showed that A separates accessions according to their origin, whereas Ci separates accessions according to their growth type. Accessions with higher Ci had lower A, indicating possibly higher rates of carboxylation per active site on the enzyme and/or higher regeneration capacity of Ribulose-1, 5-bisphosphate (RuPB) in the Calvin cycle in accession with high A.

In modern agriculture, besides providing high and stable yields, it is imperative to produce products with a high nutritive quality. The goal of this study was to determine the effect of different fertilization regimes on the macro- and micronutrients in beetroot. A 3-year field trial was set up according to a Latin square method with four types of fertilization (unfertilized control, 50 t stable manure ha−1, and 500 and 1, 000 kg NPK 5-20-30 ha−1). The mineral content was determined as follows (mg 100 g−1 in fresh weight of beetroot): 14–29 P, 189–354 K, 18–34 Ca, 17–44 Mg, 0.67–1.83 Fe, 0.41–0.65 Mn and 0.28–0.44 Zn. The highest beetroot P content was determined for the treatment with stable manure, especially in a year with dry climatic conditions. The highest beetroot K content was determined for the treatment with 1, 000 kg NPK 5-20-30 ha−1, but at the same time for the same treatment, a general decreasing trend of micronutrient content was determined, due to the possible antagonistic effect of added potassium. For better mineral status of beetroot, application of combined mineral and organic fertilizers supplemented with additional foliar application of micronutrients can be suggested.

Plant densities play an important role on plant N uptake and affecting yield quality and quantity. The main objective was to study effect of the different nitrogen levels and plant densities on N recovery and yield quality and quantity. A split-plot trial with six N levels (0, 50, 100, 150, 200 and 250 kg N ha-1) as main factor and three in-row seed distances (25, 30 and 35 cm) was conducted on private farm near Gospić, Croatia during two growing seasons in 2009 and 2010. The total fresh tuber yield increased significantly by N application in both years and by reducing in-row seed distance in 2009, but difference between N levels was insignificant. Highest fresh tuber yield with significantly fewer portions of small sized tubers was obtained by application 150 kg N ha-1 in 2009 growth season. Significantly highest tuber yield was obtained by application 150 kg N ha-1 in combination with 35 cm in-row seed distance in 2010 growth season only. By increasing in-row seed space from 25 to 35 total fresh tuber yields increased mostly by significant decreasing portion of small sized tubers and by increasing portion of medium or large sized tubers. Nitrogen recovery increased by plant density and decreased by increasing N application levels.

Aluminium (AP+) toxicity can cause inhibition of plant root growth and disturbance of its activity. A13+ can cause displacement of cations such as calcium (Ca2+) and magnesium (Mg2+) from the apoplast of root cells and in addition can inhibit their uptake. The aim of this experiment was to investigate the effect of toxic levels ofAl3+ on uptake and translocation ofCa2+ and Mg2+ of potato plants. Eleven potato cultivars were vegetatively grown on nutrient solutions pH 4, 0 with three different levels of toxic aluminium (0, 25, 0, 5 and 1, 0 mMAl3+ L-l), and control (without AI3+). After six days of growth, plants were divided on roots and shoots, and the concentrations of Al 3+, Ca2+ and Mg2+ of potato roots and shoots were determined. Significant differences in concentrations of AI3+, Ca2+ and Mg2+ in both roots and shoots were found among potato cultivars grown on nutrient solutions with different levels of AI3+. The significantly highest concentrations of A13+ in roots and shoots were determined in plants grown on nutrient solution with 1, 0 mMAI3+ L-1, 27 213 mg kg-l of dry weight (DW) and 200, 36 mg kg-l DW, respectively. Concentrations ofCa2+ and Mg2+ in roots and shoots significantly decrease with increasing A13-! concentrations in nutrient solutions, with lowest concentrations in plants grown on solution with 1, 0 mMAI3+L-1, 0, 75 % and 1, 58 % ofCa2+ and 0, 55 % and 0, 46 % ofMg2+ in roots and shoots, respectively.

The aim of this study was to determine the effect of three foliar fertilizers (Epso Salt, Megagreen and Drin) and control treatment (with no foliar fertilizer) on the chlorophyll content index, tuber size and yield of potato crop grown under water stress conditions. The experiment was conducted during three growing seasons (2005, 2006 and 2007) in the greenhouse using variety 'Courage' and arranged in a split-plot design with three replications. Foliar fertilization was carried out five times during vegetation in the period from the start of tuber formation to the stage of full tuberization. Water stress was induced at the full tuberization growth stage. There was no significant difference in chlorophyll content index in potato leaf influenced by foliar fertilizers between water stress conditions and optimum water supply. However, tuber yield was significantly reduced by an average of 15 % under water stress conditions. In addition, water stress resulted in a significantly higher number of 0-25 mm size tubers, but lower number of 50-75 mm size tubers. Foliar application of Epso Salt brought about similar tuber yields under conditions of water stress and optimum water supply. In contrast, Megagreen, Drin and control treatment achieved significantly higher tuber yield under optimum water supply when compared to water stress conditions.

The research aim was to determine the influence of different organic and mineral fertilization treatments and post-harvest treatments on the content of nitrogen and crude proteins in the edible part of beetroot (Beta vulgaris var. conditiva). A field trial (2003-2005) was set up in a hilly part of Croatia according to the Latin square method with four types of fertilization (control, 50 t ha-1 stable manure, 500 and 1000 kg ha-1 NPK 5-20-30), while treatments involved harvested fresh beetroot and stored fresh beetroot. The highest dry weight (DW) content was determined in climatologically favourable 2004 (average 14.8% DW) and in the treatment with 1000 kg ha-1 NPK 5-20-30 (15.6% DW) in harvested beetroot. In 2004 and 2005, the highest levels of nitrogen and crude proteins in harvested beetroot were determined in the treatment with 1000 kg ha-1 NPK 5-20-30 (2.41 and 2.43 g N kg-1 in fresh weight and 15.07 and 15.21 g crude proteins kg-1 in fresh weight, respectively). Regardless of fertilization treatment or studied year, nitrogen and crude protein contents were higher in stored than in harvested beetroot, by 12% on average. The lowest crude protein content was determined in treatment with stable manure what confirmed that protein content decreased by organic fertilization. It can be concluded that beetroot lost some water during the storage period, which increased its content of nitrogen and crude proteins in fresh weight and thus increased the nutritional quality of beetroot as a functional food.