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An increased awareness of environmental protection and sustainable production raise the necessity of incorporating the selection of low nitrogen-tolerant winter wheat cultivars for high yield and quality in the breeding process. This selection can be assisted by using stress screening indices. Our study aimed to evaluate and compare a number of stress screening indices and to determine and select the most nitrogen deficiency-tolerant winter wheat cultivars for further breeding. The experiment included forty-eight winter wheat cultivars from eight different countries that were grown for two consecutive years at three different locations under low-nitrogen (LN) and high-nitrogen (HN) conditions. The results emphasized the importance of applying the appropriate stress screening indices in evaluating and selecting nitrogen deficiency-tolerant wheat cultivars. The promising stress screening indices were the mean productivity index (MP), geometric mean productivity index (GMP), harmonic mean index (HM), stress tolerance index (STI) and yield index (YI). They identified cultivars Sofru, BC Opsesija and MV-Nemere as the most tolerant cultivars to LN conditions for grain yield. The same indices classified U-1, OS-Olimpija, Forcali, Viktoria and BC Tena cultivars as the most tolerant to LN conditions for the grain protein content. Using the tolerance index (TOL), yield stability index (YSI) and relative stress index (RSI), the Katarina and Ficko cultivars were denoted as LN-tolerant cultivars in terms of the grain yield and Isengrain, Tosunbey, Vulkan and BC Darija in terms of the grain protein content.

Phenolic acids (PAs) are a dominant group of phenolic compounds in cereals, existing mostly bound to compounds of cell wall. In this study, a total of 25 cereal grain samples, including wheat, winter and spring barley, corn, and popcorn, were evaluated for bound PAs and antioxidant activity in a two-year field trial. The PA contents, determined by HPLC, were significantly affected by cereal type. The mean total PA content was highest in popcorn and corn (3298 and 2213 &mu, g/gdm, respectively), followed by winter and spring barley (991 and 908 &mu, g/gdm, respectively) and wheat (604 &mu, g/gdm). Ferulic acid was the most abundant, accounting from 62% to 83% of total PAs (in popcorn and winter and spring barley, respectively). Across cereals, p-coumaric (35&ndash, 259 &mu, g/gdm) and p-hidroxybenzoic (45&ndash, 79 &mu, g/gdm) were also dominant, while in corn and popcorn o-coumaric (71 and 89 &mu, g/gdm, respectively) also occurred in higher content. The mean total phenol content ranged from 853 &mu, g GAE/gdm (wheat) to 1403 &mu, g GAE/gdm (winter barley) with DPPH scavenging activity from 14% to 67%, respectively. A significant influence of crop years on the ferulic acid and total PA content was found, while the variability of other PAs was dependent on the cereal type. The results indicated a high health benefit potential of selected cereals.

Maize (Zea mays) is an economic crop suitable for use in phytoremediation in low to moderately cadmium (Cd)- contaminated soils due to its ability to accumulate high concentration of Cd in parts of maize that are not used in human diet. The aim of this study was to test Cd content in nine female parents of the commercial maize hybrids (C1 = ♀2-48 ; C2 = ♀1767/99 ; C3 = ♀87-24 ; C4 = ♀135-88, C5 = ♀84-28 ; C6 = ♀84-44 ; C7 = ♀438-95 ; C8 = ♀30-8 ; C9 = ♀B-73) grown under field conditions in two soils (B1: eutric cambisol, B2: stagnosol) during three growing seasons (A1: 2006, A2: 2007, A3: 2008). The stationary trial was conducted in four replicates. The ear-leaves at flowering and grain at maturity were taken for chemical analysis. The average quantities of leaf-Cd were 0.081, 0.088 and 0.143 mg per kg of dry matter for A1, A2 and A3, 0.089 and 0.118, for B1 and B2, respectively. Grain-Cd was below the threshold (< 0.02 mg/kg). Five Cd-inefficient genotypes (C3, C5, C6, C7 and C9) had low leaf-Cd (average 0.049 mg/kg), while this content was about 6-times higher (average 0.299 mg/kg) in Cd-efficient genotype C4. The yield among the years ranged from 2.36 to 4.31 t/ha. Maize grown on B2 had about 26% lower yield than on B1. Five genotypes (C1, C2, C8 and C9) achieved yields less than 3.50 t/ha (mean 3.15 t/ha), while in two genotypes (C3 and C5) yields were above 4.00 t/ha (mean 4.14 t/ha). Very strong correlations (r) of leaf-Cd status among years (ranged from 0.52 to 0.77) confirmed high genetic effect on the capability of Cd accumulation in maize. However, correlations between Cd content and yield were low (ranged from –0.17 to 0.06). Cd-efficient C4 female parent could be used for development of maize hybrids suitable for phytoremediation, while Cd-inefficient female parents for hybrids could be suitable as forage maize crop contributing to the lower Cd input into food chain.

Boron (B) deficiency in maize can result in barren cobs attributed to silks being nonreceptive which is particularly important for the female parent in seed production. The objectives of this study were 1) to investigate genotypic differences among nine female inbred lines used in seed production for B concentration in ear-leaf and grain, as well as for grain yield and moisture in a three-year experiment (2006-2008) and 2) to determine response and relations among the traits when four of the female inbred lines are treated by foliar boron fertilization - three times in 10-days interval with 0.5% Solubor solution (17.5% B) during one growing season (2008). The investigations were performed on Experimental field of Agricultural Institute Osijek, (soil type: eutrical cambisol). Highly significant differences among the nine female inbred lines were detected for B concentration in ear-leaf (from 14.7 to 46.7 mg B kg-1) and grain (from 1.20 to 2.06 mg B kg-1) as well as for grain yield (from 3.33 to 4.83 t ha-1) and grain moisture (from 14.7% to 26.6%). However, there were also significant effects of growing season and the genotype by environment interaction for all four traits. Positive and moderate correlations were found between the boron status in plant and grain yield. Although B concentrations were considerably increased by foliar boron fertilization (averages 41.7 and 125.3 mg B kg-1 in leaves, 1.79 and 2.80 mg B kg-1 in grain, for control and fertilization, respectively), in general grain yield differences among treatments were non-significant. (averages 5.21 and 5.15 t ha-1, respectively).

Cadmium is a non-essential metal toxic to plants and animals. It is present in varying concentrations in soil and increased levels of cadmium negatively affect plants. In order to investigate the effects of increased levels of cadmium on mitotic index of the root, seeds of three maize genotypes with different cadmium accumulation were planted (B84, Os6-2 and their hybrid). Uncontaminated soil was used for the control treatment (approximately 0.2 mg Cd/ kg soil) and for the increased cadmium level treatment soil was contaminated with cadmium chloride (CdCl2) up to 5 mg Cd/ kg soil. Mitotic index was calculated as number of cells undergoing mitosis/total number of cells*100%. To determine cadmium uptake in the above ground parts of the plants cadmium concentration in ear- leaves was measured (by ICP-OES). Results of ICP analysis for cadmium have shown that in contaminated soil B84 line has a very low cadmium accumulation in leaves (1.321 mg Cd/kg dry weight), Os6-2 line has high cadmium accumulation in leaves (10.321 mg Cd/kg dry weight) and hybrid is in-between the two maize lines in cadmium accumulation in leaves (5.137 mg Cd/kg dry weight). Mitotic indices of B84 line and hybrid did not show reduction in contaminated soil (control - 13.64%, contaminated soil 12.4%, control - 27.17%, contaminated soil 26.89%) while Os6-2 line showed a large reduction in mitotic index in contaminated soil (control - 38.8%, contaminated soil - 6.11%) which suggests inhibition of root growth in Os6-2 line and a certain degree of tolerance in hybrid and B84 line.

Based on the Agricultural Institute Osijek trials (area of harvested plot=7, 56 m2) 2015/2016. year, in Osijek, sown with 10 wheat varieties (Srpanjka, Renata, Katarina, Felix, Vulkan, Kraljica, Tika Taka, Galloper, Osk 78/14 and Osk 138/14) in two repetitions on RCBD scheme in three fungicide treatmens (T1-treatment in stem elongation, T2-treatment in stem elongation and in heading, and T3-treatment only in heading) grain yield (dt/ha), hectolitre weight (kg/hl), thousand kernel weight (g), protein content (%) and amount of protein (kg/ha) were estimated. In stem elongation was used fungicide Sphere 0, 4 l/ha and in heading Prosaro 1, 0 l/ha. The highest grain yield (102, 63 dt/ha) and the highest amount of protein/ha (1336 kg/ha) was realised when protection against disease was conducted in stem elongation and in heading what is for +1, 30%, as well as +14, 16% higher in grain yield and 0, 92%, as well as +13, 76% in protein amount/ha in relation to fungicide protection treatment conducted only in heading or only in stem elongation. The highest grain yield in all treatments, primarily, were realised varieties Galloper, Tika Taka, Osk 78/14 and Kraljica, but also in certain treatments and Renata, Katarina and Osk 138/14. The highest amounts of protein/ha, in all treatments, were achieved varieties Galloper, Kraljica and Osk 78/14. For hectolitre weight (82, 2 ; 83, 8 ; 83, 0 kg/hl), thousand kernel weight (49, 3 ; 48, 7 ; 48, 4 g) and protein content (13, 1% ; 13, 0% ; 13, 1%) significant differences among treatments were not determined. In all treatments were realised above average thousand kernel weights for all varieties, while in other studied characteristics varieties held their specificity in greater measure.

A method which is widely accepted for the analysis of free proline content in plant tissues is based on the use of 3% sulfosalicylic acid as an extractant, followed by spectrophotometric quantification of a proline ninhydrin complex in toluene. However, sample preparation and storage may influence the proline actually measured. This may give misleading or difficult to compare data. To evaluate free proline levels fresh and frozen strawberry (Fragaria x ananassa Duch.) leaves and soybean (Glycine max (L.) Merr.) hypocotyl tissues were used. These were ground with or without liquid nitrogen and proline extracted with sulfosalicylic acid. A particular focus was the influence of plant sample cold storage duration (1, 4 and 12 weeks at -20oC) on tissue proline levels measured. Results – The free proline content analyses, carried out in leaves of Fragaria x ananassa Duch. as well as in hypocotyls of Glycine max (L.) Merr., showed a significant influence of the sample preparation method and cold storage period. Long term storage of up to 12 weeks at -20oC led to a significant increase in the measured proline in all samples analyzed. The observed changes in proline content in plant tissue samples stored at -20oC indicate the likelihood of the over-estimation of the proline content if the proline analyses are delayed. Plant sample processing and cold storage duration seem to have an important influence on results of proline analyses. Therefore it is recommended that samples should be ground fresh and analyzed immediately.

The field experiment of P and K fertilization was conducted in spring of 2004 (a = ordinary fertilization, b = a + P1, c = a + P2, d = a + P3 , e = a + P1, f = a + P2, g = a + P3 , h = a + P2K2. The amounts of added either/or phosphorus (P2O5) and potassium (K2O) were (kg ha-1) 500, 1000 and 1500, for the step 1, 2 and 3, respectively. The triplephoshate enriched with sulphur and zinc (45% P2O5 + 1. 2% S + 0.06% Zn) was used for P fertilization. Potassium salt (KCl containing 60% K2O) was source of K. Nitrogen amount was equilized for all treatments by adequate quatities of CAN (calcium ammonium nitrate: 27% N). The experiment was conducted in four replicates for crop rotation maize (2004) and soybean (2005: residual effects of the fertilization). Applied fertilization considerable influenced on increases of plant available P and K in soil, while differences of pH and humus among tretaments were in range of statistical error. Also, both P and K single fertilization gave tendency to decrease hydrolitical acidity. In general, grain yields of maize were high and ameliorative fertilization had moderate effects on maize yield as well as P and K in grain and leaves increases. Only applications of the highest K rate and PK combination resulted by significant yield increases, for 5% and 12%, respectively. Only application both P and K nutrients resulted by increase of grain quality (protein content). Residual influences of the fertilization were higher because soybean yields were increased up to 21% (influences of P), 17% (influences of K) and 30% (PK influences). However, protein and oil contents in grain were indenpendent on fertilization.

Water quantity and the application period are highly significant for achieving high yield. Also, the best results can be obtained with the proper amount of macro and micro nutrients, especially nitrogen. However, nitrogen is ecologically a very sensitive element. The climatic factors and irrigation have a great effect on the efficiency of fertilization. Therefore, the objective of this study was to examine the effects of supplemental irrigation and nitrogen fertilization on grain maize yield and yield components. The maize grain yield and yield components showed statistical differences between the 2000 growing season (10.64 t ha-1) and 2002 (12.14 t ha-1). Irrigation variant A1 (keeping soil water from 80 to 100% FWC) gave the best results in yield and in all the researched components. Medium (B2) and higher nitrogen level (B3) also gave the best results in the research except grain/ear ratio which had the best results with B1 (100 kg N ha-1). The highest level of irrigation (80-100% FWC) and nitrogen level (200 kg N ha-1) did not give statistically significant higher yield and yield components. Applying 150 kg N ha-1 in the year 2000 also proved environmentally suitable quantity of nitrogen on the researched soil since the higher level of N (B3) did not increase the yield.

Suša i kadmij su značajni okolišni čimbenici koji negativno utječu na fotosintezu biljke. Cilj ovog istraživanja je bio istražiti utjecaj kombinacije vodnog stresa i stresa uzrokovanog kadmijem na fotosintetsku aktivnost kukuruza. Sjeme tri genotipa kukuruza (B84, OS6-2 i B84xOS6-2) je posijano u plastične 20-litarske kante u pet ponavljanja. Postavljeni su tretmani: dovoljno vode/bez kadmija, dovoljno vode/5 mg Cd u tlu, nedovoljno vode/bez kadmija, nedovoljno vode/5 mg Cd u tlu za svaki genotip. Biljke su zalijevane po potrebi, a tijekom metličanja tretmani sa nedovoljno vode nisu zalijevani devet dana pri čemu je svaki dan mjerena fluorescencija klorofila. Nakon toga su opet uobičajeno zalijevani i fluorescencija klorofila je mjerena dodatnih sedam dana. Najniže Fv/Fm vrijednosti su bile kod tretmana nedovoljno vode/5 mg Cd u tlu kod linije B84(0.67) koja je također imala i najviše vrijednosti Fv/Fm parametra (0.81) u tretmanu dovoljno vode/bez kadmija. Općenito, najniže Fv/Fm vrijednosti izmjerene su u tretmanima nedovoljno vode/5 mg Cd u tlu, a najviše u tretmanima dovoljno vode/bez kadmija što ukazuje na negativan učinak kombinacije vodnog stresa i stresa uzrokovanog kadmijem. Statistička analiza je pokazala značajne učinke genotipa, dana, vode, kadmija kao i interakcije genotip×kadmij and voda×dan.

Iako su mnogi odgovori na stres specifični za pojedini tip stresa, razvidno je iz novijih istraživanja da su neki odgovori na stres općeniti, te stoga potencijalno pridonose istraživanju nespecifične tolerancije na višestruki stres. Kvantitativno-genetičke analize su identificirale genetske korelacije između svojstava tolerancije na više stresova, pokazujući da selekcija na toleranciju jednog tipa stresa je povezana sa selekcijom na toleranciju drugog tipa stresa. Naša istraživanja tolerancije na stres kod kukuruza su pokazala moguću vezu između tri gst gena i pet parametara fluorescence klorofila ukazujući na povezanost glutation transferaze (gst) s regulacijom apsorpcije fotona, disipacije energije i omjera hvatanja ekscitona i disipacije. Ovaj rezultat omogućuje vjerodostojno fiziološko tumačenje da su gst geni kod kukuruza povezani s učinkovitosti fotosinteze općenito, te konačno s tolerancijom na višestruki stres. Glavni cilj našeg odobrenog projekta Hrvatske zaklade za znanost je objasniti i integrirati genetičke i fiziološke mehanizme tolerancije na višestruki stres kod kukuruza u uvjetima povećane gustoće sklopa, suše, napada kukuruzne zlatice i infekcije fuzarija kao i prekomjerne količine kadmija u tlu. Preliminarni rezultati genetičkih i fizioloških analiza bit će prikazane.

Proizvodnja sjemena je obično veča od potreba, a dio sjemena čuva se kao zaliha. Činjenica da su agrotehnika proizvodnje i urodi sjemena povezani s više rizika (osobito suša) te ne predvidivost potreba tržišta za sjemenom uvjetuju ovakov pristup organiziranju sjemenske proizvodnje. Poljska kvaliteta sjemena se u procesu dorade i skladištenja nastoji što više očuvati, jer na taj način ostvarujemo maksimalni genetski potencijal kultivara. Ovim istraživanjem je utvrđena energija klijanja i klijavost sjemena hibrida kukuruza Ossk499, Ossk 552, Ossk 617 i hibrida suncokreta Luka i Apolon, nakon skladištenja od 12 mjeseci u podno betonskom skladištu (temperatura zraka 15-18°C i relativna vlaga zraka 65-70%). Sjeme hibrida kukuruza pripremljeno je u tri tretmana ; T-1 kontrola, dorađeno-netretirano sjeme, T-2 (aktivna tvar fludioksonil+M- metalaksil, doza 100ml/100kg semena), T-3 (aktivna tvar karboksin+tiram, doza 500ml/100kg sjemena+ aktivna tvar imidaklopirid, doza 0, 6l/100 kg semena) a hibridi suncokreta u tretmanima ; T-1 kontrola, dorađeno-netretirano sjeme, T-2 a.t. Apron XL 350 ES + Gaucho FS 600 i T-3 Apron XL 350 ES + Poncho FS 600). Na osnovu dobivenih rezultata istraživanja utvrđeno je značaj genotipa i primjene insekticida na vrijednosti energije klijanja i klijavosti sjemena tijekom skladištenja. Tretiranje sjemena hibrida kukuruza i suncokreta s pripravkom Gauchom FS 600 najviše smanjuje početnu energiju klijanja i klijavost semena kao i u svim dužinama i uslovima skladištenja semena.

A field trial with the application of 3 rates (0, 5, and 20 t ha-1) of hydratized calcite (73% CaO + 2%-3% MgO + 21% H2O) was set up in the spring of 2006. The experiment area had 3 plots of 630 m2. Each plot was divided into 4 subplots for replications. Over the next 2 years, the residual effects of liming on plant yield and nutrient uptake were investigated using maize hybrid OsSK499 in 2006 and 2007 and soybean variety Ika in 2008. The ear leaves of maize at flowering (mid-July 2006 and 2007) were analyzed for P, K, Ca, Mg, S, Zn, Mn, Fe, Cu, Mo, and B concentrations in leaf dry matter. In general, liming was more effective in 2007 than in 2006, based on the significant influence on Mg (+34%), Ca (+10%), Mo (+24%), K (-13%), B (-20%), Mn (-68%), and Zn (-19%) concentrations in the leaves. Liming increased maize yield up to 33% and 35% in 2006 and 2007, respectively. In the third year of testing, soybean responded with a considerable yield increase of up to 44%. A very high soybean yield might be the result of the high yield capacity of the Ika cultivar and favorable weather conditions. However, based on leaf analysis, the nutritional status of soybean was unbalanced because of inadequate concentrations of K, Mg, and Mo. Additionally, P, Cu, and B concentrations were at the lowest limit of an adequate status. However, the leaf nutrient status of Ca, Zn, and Mn could be defined as adequate.

Krupna i srednja frakcija sjemena tri kultivara soje (Zora, Lucija i Korana) su testirani uobičajenim metodama analize kvalitete sjemena (masa 1000 zrna, sadržaj vlage, energija klijanja - EK, standardni test klijavosti - SK) te “cold” testom (CT). Zatim je proveden test konduktiviteta sjemena (EC) “bulk” metodom na tri konstantne temperature imbibicije (10, 20 i 30oC, 24 h), uz određivanje % usvojene vode sjemenom tijekom imbibicije. Ispitivani kultivari soje se nisu značajno razlikovali po EK, SK i CT. Srednja frakcija je imala vrlo značajno veću EK i SK u odnosu na krupnu frakciju. Prema postojećoj kategorizaciji EC sjemena za krupnozrne leguminoze i CT, obje frakcije sjemena pokazuju visok vigor. EC sjemena soje je varirao od 18,0 μScm-1g-1 do 29,5 μScm-1g-1, s vrlo značajno većim vrijednostima na 30oC. Najveći EC, uz najmanji CT, utvrđen je kod sjemena kultivara Korana. Frakcija sjemena nije značajno utjecala na EC. Značajna negativna korelacija između EC i CT kod sjemena srednje frakcije indicira da je EC na 20oC pogodan za brzu analizu vigora sjemena soje, ukoliko u uzorku prevladava srednja frakcija. Količina usvojene vode sjemenom nakon imbibicije u EC je iznosila od 114,5 do 130,4% u odnosu na početnu masu sjemena. Uz značajan utjecaj kultivara, frakcije i njihove interakcije, najveći intenzitet usvajanja vode utvrđen je pri najvišoj temperaturi imbibicije i kod srednje frakcije sjemena. Dobiveni rezultati upućuju na daljnja istraživanja procesa imbibicije sjemena u laboratorijskim i poljskim uvjetima, sa svrhom boljeg poznavanja genetskog potencijala soje za otpornost na imbibicijsko oštećenje i uspješno nicanje u nepovoljnim uvjetima., Large and medium-sized seed of three soybean cultivars (Zora, Lucija and Korana) were evaluated using commonly applied seed quality analytical methods (1000 grain mass, moisture content, rate of germination - EK, standard germination test - SK) as well as cold test (CT). Afterwards, seed electrical conductivity test (EC) - „bulk“ method - was performed at three constant temperatures (10, 20 and 30oC, 24 h), with subsequent determination of seed water uptake during imbibition, as the % of the initial seed sample weight. The tested soybean cultivars did not show significant differences regarding EK, SK and CT. Medium-sized seed showed very significantly higher EK and SK in comparison with large seed. According to the current EC evaluation scale for large-seeded legumes and CT values, both seed categories expressed high vigour. EC test varied between 18.0 – 29.5 μScm-1g-1, and significantly higher values were seen at 30oC during imbibition. The highest EC and the lowest CT values were obtained with the seed of cultivar Korana. Seed size had no effect on EC test value. The established significant negative correlation between EC and CT in medium-sized seed implies that EC test performed at 20oC could be suitable tool for fast soybean seed vigour analyses, if medium-sized seed dominated in seed sample. Seed water content after imbibition in EC test varied between 114.5 - 130.4% regarding seed initial weight. Considering significant influence of cultivar, seed size category and their interaction, the highest water uptake rate was observed at the highest imbibition temperature applied, as well as in medium-sized seed. These results suggest further investigation of seed imbibitional processes in both laboratory and field conditions, with aim of better comprehension of soybean genetic potential in imbibitional damage resistance and successful emergence in adverse conditions.

A method which is widely accepted for the analysis of free proline content in plant tissues is based on the use of 3% sulfosalicylic acid as an extractant, followed by spectrophotometric quantification of a proline-ninhydrin complex in toluene. However, sample preparation and storage may influence the proline actually measured. This may give misleading or difficult to compare data.To evaluate free proline levels fresh and frozen strawberry (Fragaria × ananassa Duch.) leaves and soybean [Glycine max (L.) Merr.] hypocotyl tissues were used. These were ground with or without liquid nitrogen and proline extracted with sulfosalicylic acid. A particular focus was the influence of plant sample cold storage duration (1, 4 and 12 weeks at -20°C) on tissue proline levels measured.The free proline content analyses, carried out in leaves of Fragaria × ananassa Duch. as well as in hypocotyls of Glycine max (L.) Merr., showed a significant influence of the sample preparation method and cold storage period. Long-term storage of up to 12 weeks at -20°C led to a significant increase in the measured proline in all samples analysed.The observed changes in proline content in plant tissue samples stored at -20°C indicate the likelihood of the over-estimation of the proline content if the proline analyses are delayed. Plant sample processing and cold storage duration seem to have an important influence on results of proline analyses. Therefore it is recommended that samples should be ground fresh and analysed immediately.

Šest hibrida kukuruza šećerca (OS 250su., OS 254su., Bc 274su., Bc 378su, Spirit i Bonus) posijano je u poljskom pokusu u 2009. i 2010. godini na lokaciji Županja u tri varijante gnojidbe (130, 150 i 180 kg K2O/ha). Utvrđeno je značajno poboljšanje gospodarskih svojstava kukuruza šećerca pri povećanoj gnojidbi kalijem (180 kg K2O/ha) u odnosu na kontrolu (130 kg K2O/ha), ranije metličanje i svilanje za 3 do 7 dana, veća težina klipa za 10%, veći promjer klipa za 18% te udio zrna veći za 3%., During 2009 and 2010 in the field trial in Županja six sweet corn hybrids (OS 250S., OS 254su., BC 274su., BC 378su., Spirit and Bonus) were sown in three variants of fertilization. The potassium (K) fertilization significantly improves characteristics of sweet corn. Increased potassium fertilization (T3 - 180 kg K2O) compared with control (T1 - 130kg K2O) results in a larger diameter of cobs (20%), higher cob weight (10%) and an earlier tasseling and silking for 3 to 7 days.

Tretiranje sjemena hibrida kukuruza je neizostavan dio procesa dorade sjemena. Sjeme kukuruza najčešće je tretirano nekim od fungicida, a u poslijednjih par godina zbog problema sa žičnjacima i kukuruznom zlaticom u ponudi je sjeme tretirano i insekticidom. Cilj ovih istraživanja bio je utvrditi promjenu energije klijanja i standardne klijavosti kukuruza tijekom tri godine skladištenja na dva genetski različita hibrida (OSSK-596 i OSSK-602) kreiranih na Poljoprivrednom institutu Osijek. U istraživanjima oba hibrida testirano je netretitano sjeme te sjeme tretirano u tri varijante: 1.fungicid A ; 2.fungicid B ; i 3.fungicid + insekticid. Rezultati istraživanja pokazuju da tijekom tri godine skladištenja dolazi do pada energije klijanja i standardne klijavosti. Najveći gubitak kvalitete sjemena tijekom trogodišnjeg skladištenja zabilježen je s varijantama sjemena oba hibrida tretiranih suspenzijom fungicida i insekticida. Značajan pad energije klijavosti iskazan je već nakon 12 mjeseci skladištenja kod oba istraživana hibrida, dok je značajni pad standardne klijavosti uočljiv nakon 24 mjeseca skladištenja. Na temelju dobivenih rezultata kvalitete sjemena kukuruza ispitivanih tretmana, sjeme tretirano suspenzijom fungicida i insekticida nije pogodno za skladištenje duže od 12 mjeseci u skladištima koja nemaju mogućnost kontroliranja temperature i vlage zraka, te bi se takovo sjeme trebalo zasijati u godini tretiranja.

U proizvodnji sjemena visoke kakvoće bitni su vremenski uvjeti proizvodnje, vrsta kultivara, prisustvo štetnika u polju, povoljan sadržaj vode u zrnu, sadržaj ulja u zrnu, oštećenja zrna u doradi sjemena, primjena pesticida, ambalaža, uvjeti i trajanje uskladištenja, biokemijska oštećenja tkiva sjemena tijekom skladištenja, prisustvo bolesti i štetnika. Istraživanjem je analizirana energija klijanja i klijavost sjemena soje (Ika, Kuna) i suncokreta (Apolon, Favorit) nakon skladištenja u dva uvjeta skladištenja (S1 uvjeti skladištenja: 5-40oC i relativna vlaga zraka 45-70%, S2 uvjeti skladištenja: 15oC i relativna vlaga zraka 65 do 70%). Rezultati istraživanja pokazali su da suncokret u odnosu na soju duže održava energiju klijanja i klijavost sjemena. U uvjetima skladištenja S1 smanjenje vigora sjemena bilo je od 15 do 49% a klijavosti od 12 do 46%. U uvjetima skladištenja S2 u odnosu na skladišne uvjete S1 prosječno smanjenja vigora soje i suncokreta nakon tri godine skladištenja bilo je manje od 5 do12%, a klijavosti od 3 do 28 %.

Objectives of this investigations were to determine effects of nozzle wear on some most important spray characteristic. In detail, flow rates, spraying angle and distribution pattern were checked and compared with data taken from firms informations. The investigated nozzles were flat fan type, made from different materials. Flat fan nozzles are the most common used tip of nozzles in applying pesticides in Croatian arable farming. The relative wear rates of nozzle materials varied greatly with differnt time of use. At the end of test periods, hardened stainless was the most resistant to wear, followed, by stainless steel, plastic and brass nozzles. Nozzles with lower flow rates wore at faster rates compared to nozzles with higher flow rates. Analyzing the spray angles it was determined that an increase in flow rate due to nozzle wear corresponded to a reduction in the spray angle. There was little difference between the spray deposit distributions of new and worn fan nozzles in widths of patterns. However, the worn nozzles delivered greater volumes of liquid in the centers of patterns., Cilj istraživanja bio je utvrditi utjecaj trošenja otvora mlaznica ratarskih prskalica na neke najznačajnije karakteristike mlaza. Ispitivani su i mjereni protoka tekućine (l/min), kut mlaza, te raspodjela tekućine po površini, kao najznačajniji kvalitativni parametri mlaza. Isti imaju presudan utjecaj na preciznost i učinkovitost pri kemijskoj aplikaciji pesticida. U ispitivanje su uzete mlaznice s lepezastim spljoštenim mlazom, s kutom mlaza 1100, izrađene od četiri različite vrsta materijala. Mlaznice s lepezastim spljoštenim mlazom su najčešće korišteni tip mlaznica na prskalicama u ratarskoj proizvodnji u Hrvatskoj. Relativno trošenje otvora mlaznice izrađenih od različitog materijala, značajno je variralo s vremenom uporabe mlaznice, izraženo u radnim satima. Na kraju perioda testiranja utvrđeno je da su mlaznice izrađene iz otvrdnjenog nehrđajućeg čelika bile najotpornije na trošenje, a slijedile su ih mlaznice od nehrđajućeg čelika, plastične, te mlaznice izrađene iz mjedi (mesinga). Ispitivanjem je utvrđeno da su se mlaznice s manjim nazivnim kapacitetom (količina protoka tekućine kroz mlaznicu, l/min), trošile brže u usporedbi s mlaznicama većeg nazivnog kapaciteta. Mjerenjem izlaznog kuta mlaza utvrđeno je da je povećanje količine protoka mlaznice uslijed trošenja njezina otvora korespondiralo sa smanjenjem kuta mlaza. Ispitivanje ujednačenosti površinske raspodjele tekućine obavljeno je na ispitnom stolu. Utvrđene su male razlike u ujednačenosti poprečne raspodjele između novih i trošenih mlaznica. Ipak, trošene mlaznice su dale veći volumen tekućine u centru mlaza u usporedbi s novim mlaznicama.

Prinosi suhe tvari i bjelančevina važan su čimbenik u stvaranju novih kultivara krmnih kultura. Kroz dugi niz godina oplemenjivanja postignut je mali genetski napredak u povećanju kakvoće lucerne. Stoga smo istraživali mogućnost korištenja lokalnih populacija lucerne u svrhu povećanja kakvoće direktnom i indirektnom selekcijom. Dobiven je jak i opravdan utjecaj genotipa i okoline na svojstva prinosa suhe tvari i odnos list/stabljika kao i njihove interakcije na razini značajnosti P, Yields of dry matter and protein are important factors in selection of fodder crop cultivars. During the long time of fodder crops breeding for quality alfalfa a small genetic gain was achieved. Therefore we investigated possibility of using local populations of alfalfa to increase quality with direct and indirect selection. Strong and significant influence of genotypes and environments was recorded for yield of dry matter and leaf/stem ratio examined traits and their interactions at the level p

The results of the performed investigation led to the conclusion that FE was correlated to SG, but CT and EC were more reliable seed vigour related to field emergence. Seed deterioration during storage was certified by laboratory tests and field experiments and it was more expressed in the adverse soil and weather conditions after planting. However, established significant cultivar differences in seed vigour preservation, implicated the possibility for usage of genotypes with higher seed vigour potential in soybean selection and successive stand establishment even in suboptimal environmental conditions in the period from planting to emergence.

Istraživanjem je prikazana proizvodnja sjemena u Republici Hrvatskoj od njezinih početka, trenutnog stanja do budućeg razvoja. Za prikaz su odabrane važnije sastavnice proizvodnje kao i vremenska razdoblja koja su obilježila proizvodnju sjemena u R.H. U Hrvatskoj je danas godišnja proizvodnja sjemena na oko 30.000 ha s proizvodnjom oko 200.000 t sjemena Istraživanjem su obuhvaćene potrebe za sjemenom, organizacija sjemenske proizvodnje, površine za sjemensku proizvodnju, doradbeni kapaciteti, distribucija, cijena, izvoz i uvoz sjemena., This investigation show seed production in Croatia from begining to the present state and future possibilities. Research emphasize important seed productions as well as specific time period. Present seed production in Croatia is organized on 30 000 ha and approximatly 200 000 t grain yield per year. Investigation included seed request, organization of seed production, seed production areas, seed processing capacity, distribution, costs, seed export and import.

Poljoprivredni institut Osijek osnovan je 1875. godine na inicijativu tadašnjeg „Hrvatskog gospodarskog društva" u Osijeku, imenom "Agro-kulturno kemijski zavod". Pod nazivom Poljoprivredni institut Osijek radi neprekidno od 1961 . godine. U svom dugogodišnjem radu je značajno utjecao na unapređenje proizvodnje kvalitetnog sjemena. Tako su izgrađeni centri na: PIK-u Belje, VUPIK-u Vukovar, IPK-Oranica Osijek, PP Garešnica itd. U suradnji s poljo-privrednim kombinatima organizirao je proizvodnju i doradu sjemena te plasirao velike količine sjemena na domaćem i inozemnom tržištu. Prve količine sjemena hibridnog kukuruza (dvostruki križanci) Institut je proizveo 1958. godine u količini od 5.384 kg. Značajna proizvodnja OS hibrida kukuruza pocinje 70-ih godina, a komercijalno povećanje sjetvenih površina od 1975. godine. Najveća proizvodnja sjemena OS hibrida kukuruza bila je 1978. godine (7.846 ha- 12.239 t) a najmanja 1998. godine (147 ha-250 t). Poljoprivrednom Institutu je do danas priznato 116 hibrida kukuruza, od kojih se u širokoj proizvodnji nalazi svake godine 10-12 hibrida, FAO grupe 100-700. U strukturi sjetve merkantilnog kukuruza OS hibridi zauzimaju od 15 do 18% sjetvenih površina. Sjeme OS hibrida kukuruza danas se proizvodi u: Mađarskoj, Turskoj, Srbiji i Crnoj Gori, Slovačkoj, Kazakstanu., Agricultural Institute Osijek is the oldest institution for breeding and seed production in Croatia. Agricultural Institute Osijek established in 1875, on initiative „Croatian managing society“ with the name „Agro-cultur chemical Institut“. With the name Agricultural Institute Osijek work since 1961 and thru many years it has significant influence on quality seed production improvement. In the purpose of seed production improvement, Agricultural Institute Osijek has started with establishing particulary processing centers in cooperation with other managing subject, like technicaly key for further development and improvement of seed production. Processing centers has build on PIK Belje, VUPIK Vukovar, IPK Oranica Osijek, PP Garešnica etc. Agricultural Institut Osijek in cooperation with Agricultural combinat already organized production and processing of seed and also delivered a large amounts of seed on domestic and foreign market. The first hybrid maize seed (double - cross) Agricultural Institute Osijek produced in 1958 in amounts of 5 384 kg. Significant production of OS maize hybrids began in the early 70's and commercial increasing of sowing surface f rom 1975. The largest production of OS maize hybrids was in 1978 with (7 .846 ha- 12.239 t ) and the smallest in 1998 (142 ha- 250 t). Today, Agricultural Institute Osijek has 116 registered maize hybrids FAO group 100-700. 10 to 12 of them are widespread in production every year. In total sowing structure in Croatia, OS maize hybrids occupied 15-18% of totaly sowing surface. Today, OS maize hybrid seed production established in some foreign countries like Hungary, Turkey, Slovenia, Serbia and Montenegro, Slovakia and Kazahstan.

Hibridi OSSK 373, OSSK 444, OSSK 494 i OSSK 552 različitih grupa zriobe (FAO grupe 350, 450, 490 i 590) uzgajani su na jedanaest lokacija kroz pet godina (1999.-2003.) u makropokusima od Račinovaca (okolica Županje) do Luke (okolica Varaždina). Eksperimentalna parcela sastojala se od osam redova dužine 100 metara. Parcela je obrana kombajnom, izmjerena je vlaga zrna i utvrđena masa zrna s parcele preračunata u t/ha. Trofaktorijalnom analizom pokusa utvrđen je vrlo značajan utjecaj (F-test) sva tri promatrana činitelja: lokaliteta, godine proizvodnje i hibrida na prinos i vlagu zrna. Urod zrna bio je značajno veći kod kasnijih hibrida, a najveći prinos imao je hibrid OSSK 552 (12.16 t/ha). Trend porasta vlage zrna kasnijih hibrida na zapadnijem području bio je značajan, ali apsolutne vrijednosti vlage zrna ipak nisu bile ekstremne (ispod 29%). Uzevši u obzir potencijal rodnosti kasnijih hibrida kukuruza kao i njihovu moguću (pre)namjenu (berba u klipu i/ili proizvodnja silaže) postoji osnova za povećanje zastupljenosti kasnijih hibrida kukuruza na sjetvenim površinama sjeverozapadne Hrvatske., The hybrids OSSK 373, OSSK 444, OSSK 494, OSSK 552 of different FAO maturity groups (FAO groups 350, 450, 490 and 590 respectively) were grown at eleven locations in five years (1999-2003) in macro trials from Račinovci (near Županja) to Luka (near Varaždin). There was an experimental plot of eight rows 100 metar long. Entire plots were machine harvested and the whole quantity of grain was weighed, calculated in t/ha and grain water content was determined. In combined ANOVA, all three effects: location, year and hybrid, were highly significant (F-tast) for two agronomic traits, grain yield and grain water content. Grain yield was significantly higher in later hybrids and OSSK 552 was highest yielding hybrid with 12.16 t/ha. Going westward, water content increased more rapidly in later hybrids, but the magnitude of water content was not excessive (below 29%). Taking higher yield potential of later hybrids into account, as well as possible switching of type of production (grain and/or forage production), it is feasible to increase production of later hybrids in North-West Croatia.

Pomoću indeksa poljskog nicanja (FEI = poljsko nicanje/standardna klijavost x 100) u radu je prikazana veza standardne klijavosti (SG) i poljskog nicanja (FE) soje. Indeks je promatran pod utjecajem nekoliko važnih činitelja vigora sjemena soje: kultivara, starosti i tretmana sjemena fungicidom kao i različitih uvjeta u sjetvi. Rezultati ispitivanja upućuju na to da sjeme odgovarajućeg vigora (SG≈85%) ima podudarne vrijednosti SG i FE (SG≈FE, FEI≈1 00). U tom slučaju SG precizno je predviđala FE, a prilikom sjetve takvog sjemena nije bilo rizika ukoliko sjeme nije tretirano fungicidom prije sjetve ili ako je sjetva obavljena u manje povoljnim uvjetima u polju. Nasuprot tomu, kod sjemena reduciranog vigora (SGFE, FEI= 40-100), tj. postojala je velika mogućnost smanjenog FE u odnosu na SG. Međutim, prilikom korištenja ovakvog sjemena, tretman sjemena fungicidom i sjetva u povoljnijim ekološkim uvjetima značajno su pridonijeli tomu da se u poljskim uvjetima ponove rezultati iz laboratorija (SG≈FE, FEI≈100). Ovo saznanje može značajno smanjiti rizik u sjetvi i pridonijeti postizanju odgovarajućih sklopova biljaka u polju., In the paper are presented relationship between standard germination (SG) and field emergence (FE) with field emergence index (FEl= field emergence/ standard germination x 100). Index was showed under influence of few important factors of seed vigor: cultivar, seed age and seed treatment as well as different seedbed conditions. Results showed that the seed with optimal vigor (SG≈90%) has very similar SG and FE values (SG≈FE, FEI≈100). That means that during the sowing of such seed, there was no risk if we use untreated seed or if there are unfavorable field conditions. On the contrary, by seed with reduced vigor (SGFE, FEI=40-100), there was a very great possibility of reduced FE. lf we use such seed, fungicide seed treatment and sowing in optimal seedbed conditions can significantly contribute to the repetition of laboratory results in field condiitons (SG≈FE, FEI≈100). This knowledge can significantly reduce risk in sowing and contribute to improvement of soybean seed performance and stand establishment.

Sjeme suncokreta specifičnih je svojstava s obzirom na proces dorade i skladištenje. Tijekom skladištenja često dolazi do opadanja kakvoće sjemena, a pri tomu značajnu ulogu imaju: genotip, duljina i uvjeti skladištenja, tretman sjemena, vrsta ambalaže i dr. Ovim istraživanjem utvrđeno je opadanje energije klijanja i klijavosti sjemena suncokreta, a ispitivanje je obavljeno na netretiranom (kontrola) i tretiranom sjemenu (T1 : Geocid ST-35 i T2: Apron 35 DS). Analizirano je sjeme tri hibrida suncokreta Poljoprivrednog Instituta Osijek (Fakir, Orion i Olio) tijekom dvije godine skladištenja u "jumbo" vrećama (1999., 2000., 2001). Utvrđeni pad energije klijanja i klijavosti tretiranog sjemena, u prosjeku za sva tri hibrida, kretao se od 3 do 13%, a pad klijavosti netretiranog sjemena bio je manje izražen i iznosio je 2-5%. Najveći pad klijavosti zabilježen je na sjemenu hibrida Olio (13%), a najmanji na sjemenu hibrida Fakir (3%)., Sunflower seed have specific characteristic considering seed processing, storage and seed treatment. During the storage time of seed supply, seed quality is often reduced. Significant influence on reduction of seed quality have: hybrid, storage time and conditions, the way of packing seed and seed treatment. This research analyse decreasing of seed germination viability and germination on untreated (control) and wet treated seed T1 (Geocid ST-35) and T2 (Apron 35 DS) on three hybrids of sunflower created on Agricultural institute Osijek (Fakir, Orion, Olio) during the three year of storage in „jumbo“ bags (1999, 2000 and 2001). Treated seed of all three hybrids had reduced germination viability and germination of seed from 3-13%. Untreated seed had smaler reduction (2-5%). The bigest reduction of germination viability and germination of seed had hybrid Olio (13%) and the smallest hybrid Fakir (3%).