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.
Up to date, there are no reports on the effects of combined sulfur (S) and nitrogen (N) foliar application in olive orchards on volatile compounds and sensory characteristics of virgin olive oil ...(VOO). In this work, the effects of increasing the fertilizer S and N concentration on volatile compound composition and odor and taste attributes of monovarietal VOOs of Istarska bjelica and Leccino cultivars were investigated. The volatile compounds were analyzed by gas chromatography with flame ionization and mass spectrometric detection after isolation by solid-phase microextraction, while sensory attributes were assessed by a professional panel. In all the investigated VOO samples, aldehydes were the most represented group of compounds, with (E)-2-hexenal as the most abundant, followed by (Z)-3-hexenal and 1-penten-3-one. Significant differences in the volatile profiles and sensory attributes were observed between VOOs from different treatments, mainly attributable to the interactions between all the factors that were investigated: treatment, cultivar, and year. Although significant interactions were noted for sensory attributes as well, the score for overall quality was generally lower for Leccino VOOs and for VOOs from both cultivars that were obtained after the highest SN dose treatment. All the samples were graded by overall sensory scores that were higher than eight and were characterized by well-pronounced fruitiness and the absence of sensory defects. The results of this study showed that foliar application of S and N significantly affects the quality of VOO, confirming that such a practice can modulate the characteristic olive oil odor and taste attributes and thus possibly influence its acceptability and preference among consumers.
This study investigates the effect of combined sulfur (S) and nitrogen (N) foliar fertilization on leaf S and N concentration, as well as on the growth of olive fruit and on the quantity and quality ...of olive oil, obtained from two olive cultivars ‘Istarska bjelica’ and ‘Leccino’ in two consecutive years. S and N are some of the most important nutrients, and both play a crucial role in plant oil production. The here-reported fertilization program significantly increased S concentration in leaves without affecting N concentration, which led to an increase in fruit yield and improvement of all fruit morphological parameters. The best oil yield per tree was obtained under the treatment with the highest S/N dose. Oil quality was not affected by S and N supply, and this allowed us to classify all our oil samples as extra virgin (EVOO). Regarding the content of total phenols (TPC) and composition of fatty acid methyl esters (FAME), they remained unaltered under the applied treatments. All investigated fruit morphological parameters, as well as fruit and oil yield, were highly cultivar-dependent. ‘Istarska bjelica’ was characterized as a cultivar with higher fruit mass and pulp percentage, while its stone parameters were lower than those of ‘Leccino’. Consequently, the extraction oil yield obtained from ‘Istarska bjelica’ fruits was much higher. Moreover, environmental conditions had a great impact on fruit and oil quantity. The here-obtained results led us to the conclusion that supply of S and N can enhance oil production without affecting its nutritional quality, a finding that could generate large long-term effects on economic growth in the olive oil sector.
The must used to make sparkling wine has a low pH value and moderate sugar content, and its potassium content can have a strong influence. An excess of potassium often leads to an insufficient supply ...of magnesium, since potassium has a strong antagonistic effect on magnesium, and, consequently, to poorer photosynthesis and a poorer quality of the must. The aim of this study was to determine whether the application of foliar fertilizers based on magnesium, phosphorus, and amino acids could reduce leaf potassium content, affecting the reductions in sugar content and pH value and increasing the total acidity of the must. A fertilizer trial with three replicates was conducted on the cultivar Istrian Malvasia (TCtrl—NPK, TMg—NPK + Agromag (6% MgO), TMgP—NPK + Agromag + Fosforo (30% P2O5) i TMgPBS—NPK + Agromag + Fosforo + Bio Prot) in a random complete block design. The NPK fertilizer was applied in the autumn. Foliar fertilization was applied three times during the growing season (31 May, 7 July, and 22 August 2014), and leaf samples were collected for leaf analysis before each application. The results show that foliar fertilization significantly reduced leaf potassium content, especially when treated with magnesium alone (treatment TMg). In addition, foliar fertilization significantly lowered the pH and increased the sugar content of the must. The results obtained in this research give a scientific contribution to the creation of fertilizer treatments for vines with a positive effect on the basic chemical composition of the base wine and provide a good basis for further research in reducing the use of certain enological practices during production.
Soil is a non-renewable resource, so it should be taken care of it. High quality food with sufficient yield for a growing human population can be produced only if plant nutrients are added to the ...soil by fertilizers to increase soil fertility, but the fertilizers have to be used economically, with the aim of raising the nutrient content available in the soil in order to meet plants' needs. The goal of the present investigation was to determine the effect of application of organic and mineral fertilizers as well as the effect of research environment on micronutrient content in red beet root. 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 stable manure*ha.sup.-1, 500 and 1,000 kg NPK 5-20-30*ha.sup.-1). After digestion of plant material with concentrated HNO.sub.3, iron, manganese, and zinc were determined by an atomic absorption spectrophotometer (AAS). The highest average red beet root micronutrient contents (270 mg Fe*kg.sup.-1 in dry matter, 96 mg Zn*kg.sup.-1 in dry matter, and 53 mg Mn*kg.sup.-1 in dry matter) were determined in the first research environment (Braljevica in 2003) with low potassium soil content. There was a general decreasing trend in contents of the studied micronutrients (Fe, Mn and Zn) with NPK 5-20-30 fertilization (and by application of high doses of potassium), certainly due to antagonistic activity with potassium. It is suggested to fertilize with both 500 kg NPK 5-20-30*ha.sup.-1 and microelement fertilizers.
There are limited numbers of scientific publication regarding genotypic differences which exist among olive cultivars concerning nutrient uptake and translocation. For that purpose, the object of our ...study was to determine possible differences between leaf mineral content of five selected olive cultivars since leaf nutrient analysis is consider being the best method for diagnosing olive tree nutritional status. Plant material was obtained from an olive collection, grown on calcareous soil maintained at Institute of Adriatic Crops and Karst Reclamation, Split, Croatia. The study was conducted with two Croatian autochthonous olive cultivars (“Istarska bjelica”, “Lastovka”), two Italian cultivars (“Pendolino”, “Leccino”) and one Spanish cultivar (“Hojiblanca”). Completely randomized design was applied. This study has shown questionably low Mg concentration in all olive cultivars with exception for “Hojiblanca” cultivar. Also, only Croatian cultivars “Istarska bjelica” and “Lastovka” as well as Spanish cultivar “Hojiblanca” recorded sufficient levels of iron leaf mineral content. Regarding other elements studied (P, K, Ca, Zn, Mn, Cu) all cultivars were above literature cited thresholds for possible deficiencies. Selected olive cultivars in our experiment demonstrated different nutrient leaf concentration, which is of particular importance for fertilization requirements and fertilization practice in Croatian orchards grown on calcareous soil.
To differentiate effects of netting and attribute them to crop, cultivar, planting density, climate, net type and colour, ca. 200 publications were scanned originally. Apple was chosen as a model ...crop due to the majority of reports, wide variation with many varieties and growing locations worldwide in the Northern and Southern hemisphere, but the results may be useful for other fruiting plants. After meeting strict selection criteria, a meta-analysis of 26 internationally published peer-reviewed articles was based on seven varieties and seventeen locations with a diverse range of climates. A novel Main Effects Meta Principal Components Analysis (ME Meta-PCA) was developed and provided unexpectedly uniform results: Location (climate), planting density and hail net (type and colour) had negligible impacts. Fruit (red) colour, most adversely affected by netting, correlated with TSS viz fruit sweetness, as often postulated in consumer studies, followed, to a smaller extent, by sugar/TSS, fruit firmness and acidity but small increase in fruit mass—i.e. maintenance of fruit quality under netting over all seven varieties (Braeburn, Gala, Elstar, Jonagold, Pinova and Fuji) examined and locations worldwide. While Jonagold and the early ripening Gala appeared suitable, unaffected and stable in the netting effects in the ME Meta-PCA, Pinova was the least suitable for cultivation under netting. Interestingly, late ripening cultivars (Braeburn and Cripps Pink) were both positively influenced by desired earlier ripening under netting. These effects on fruit quality are discussed with respect to shade adaptation under netting and countermeasures such as easy colouring mutants or reflective mulches.
U radu je istraživan utjecaj kultivara i tipa reznice na postotak ukorjenjivanja i duljinu korijena reznica američke tuje (Thuja occidentalis). U pokus su bili uključeni kultivari 'Columna' i ...'Smaragd' u kombinaciji s tri tipa reznice tj. jednostavne reznice, reznice s petom te reznice s dijelom grane. Postotak ukorjenjivanja reznica bio je pod značajnim utjecajem kultivara i tipa reznice, dok je duljina korijena bila pod značajnim utjecajem tipa reznice. Kod kultivara 'Smaragd' zabilježen je veći prosječni postotak ukorjenjivanja nego kod kultivara 'Columna'. Veći postotak ukorjenjivanja zabilježen je kod oba kultivara uz upotrebu reznica s dijelom grane i jednostavnih reznica, u usporedbi s reznicama s petom. Prosječna duljina korijena reznica s dijelom grane bila je signifikantno veća i od prosječne duljine korijena jednostavnih, i reznica s petom, neovisno o kultivaru. Kako bi se postiglo bolje ukorjenjivanje, u rasadničarskoj proizvodnji oba kultivara preporučuje se upotreba reznica s dijelom grane.
Influence of cultivar and type of cuttings on rooting percentage and root length in northern white cedar (Thuja occidentalis) was investigated. Two cultivars ('Columna' and 'Smaragd') with three types of cuttings (simple, heel and mallet cuttings) were included in the trial. Rooting percentage was significantly influenced by the cultivar and type of cuttings while the root length was significantly influenced by the type of cuttings. Higher average percentage of rooted cuttings was recorded in cultivar 'Smaragd' compared to 'Columna' cultivar. Average percentage of rooted cuttings was higher in both cultivars with the use of mallet and simple cuttings, compared to heel cuttings. Average root length of mallet cuttings was significantly longer than average root length of both simple and heel cuttings, independently of cultivar. In order to achieve better rooting, in the nursery production of both cultivars, use of mallet cuttings is recommended.
Since the produced Paška sheep milk is entirely processed in Pag cheese, it is of great importance to ensure a uniform milk production of prescribed chemical composition and hygienic quality. In ...addition to genotype, as the most important factor, the production and quality of sheep milk is affected by numerous physiological factors, so the aim of this research was to determine the influence of paragenetic factors (stage and number of lactation) on daily milk yield and chemical composition (total solids, milk fat, protein, casein, lactose, total solids non fat) of Paška sheep milk. Three herds were chosen by random selection within the areas of Kolan and Caska, and survey was conducted on a total of 213 Paška sheep. Stage of lactation was divided to: the beginning (to 50th-day), the middle (from 51st till 100thday) and the end (101st -day till dry out) of lactation. Depending on the number of lactation, sheep were grouped into five groups (1st, 2nd, 3rd, 4th, 5th and others). A significant influence of stage and number of lactation on average daily milk yield and analysed chemical composition parameters was determined. The Paška sheep had the highest daily milk production in the mid lactation (773 g), and the third lactation (712 g) recorded. At the end of lactation, total solids, milk fat, protein, casein, total solids non fat in milk were significantly higher than at the beginning and middle of lactation. The highest share of total solids, milk fat, protein and casein was determined in Paška sheep milk at 5th lactation and other lactations. Between the individual parameters significantcorrelation coefficients were determined.
Recent global warming and more frequent droughts are causing significant damage to maize production. A reliable estimate of drought intensity and duration is essential for testing maize hybrids to ...drought tolerance. For this purpose, the self-calibrating 10-day palmer drought severity index (scPDSI) and standardized precipitation index (SPI) for 1, 2, 3, 6, 9, 18, 27, and 36 10-day scales were used to estimate the effects of drought on grain yield of 32 maize hybrids evaluated in 2017 and 2018 at eight experimental locations in the Pannonian part of Croatia. Time series of observed 10-day mean air temperature, relative humidity, and precipitation totals for a set of “reference” weather stations of the croatian meteorological and hydrological service (DHMZ) for the period 1981–2018 were used to calculate the scPDSI and SPI indices. According to the 10-day scPDSI and SPI for different time scales, 2018 proved to be a “normal year,” while 2017 experienced a “mild to moderate drought,” which resulted in a 13% reduction in maize grain yield at eight experimental locations compared to 2018. The correlation between grain yield and drought indices for summer months was the highest for the 10-day scPDSI. To some extent, correlations between summer months’ SPI for the 3 10-day time scale and maize grain yield were comparable to the corresponding correlations for the 10-day scPDSI. However, for other SPI time scales considered, the corresponding correlations were weaker and less informative. The dependence of grain yield on scPDSI values was not the same for all hybrids, indicating their different tolerance to drought. The reduction in grain yield due to drought was primarily caused by insufficient grain filling (lower 1000-grain weight) and, to some extent, by a reduction in the number of grains. In this study, application of 10-day scPDSI data proved to be more relevant in detecting effects of drought on agronomic traits than application of SPI data for the most time scales.
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