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Monitoring genetic uniformity and identity is very important in maize breeding and seed production. Due to practical reasons, molecular and biochemical methods for the determination of genetic purity and uniformity should reliably reflect genetic differences associated with traditional morphological traits, even when they are not agriculturally important. A comparison of genetic purity and uniformity of one maize hybrid lot, based on morphological UPOV markers and the UTLIEF (Ultrathin-layer isoelectric focusing) method is performed in this research. Tested hybrid samples expressed uniform protein markers profiles, but on the other hand, unsatisfactory uniformity of morphological markers in the field, indicating some laches in seed production. Although the UTLIEF method, standardized by ISTA rules, provides enough accurate distinction between F1 seed and self-pollinated maternal seed, a "clean" isozyme or protein profile will not necessarily correlate with morphological homogeneity. It is most likely that the non-uniformity of the tested hybrid lot originates from the non-uniformity of one of the parental lines. Therefore, to establish where the laches occurred, it is necessary to perform post-control tests with reference samples of maize hybrid and parental lines, as well as, the insight into their official descriptions according to the UPOV descriptor. Thus, it is very important to require the deposition of referent samples of hybrids and varieties whose seed production is allowed in Serbia, as well as to have harmonised protocols for conduction of laboratory and field post-control tests.

Black soybean seed coat has a considerable content of anthocyanins which can provide a positive effect on the health of the consumers through food products enriched with the extracts of these valuable bioactive compounds. Nevertheless, the use of soybean seed coat, a by-product from soybean processing, additionally valorizes this raw material. The possibility of enrichment of sweet maize grains with anthocyanin extract was investigated. Several procedures with acetic acid were applied in the experiments of anthocyanins extraction from black soybean seed coat. During the marination process, the grains were stained, changing their standard yellow color to a crimson red. Since the brines with the addition of citric acid became cloudy (opalescent) after some time, lactic acid was used as an anthocyanin stabilizer in the continuation of the research. Depending on the extraction conditions, the spectrophotometrically determined content of total anthocyanins in the solution varied from 3541.90 to 5387.70 mg CGE/g d.m., and in the marinated maize grain between 179.89 and 286.05 mg CGE/g d.m. After seven days, the total anthocyanin content in the grain did not increase significantly, so this aging period was selected as optimal for marinating maize products.

Four commercial wholegrain flours made from differently colored kernels of maize genotypes produced in Maize Research Institute "Zemun Polje" were used as the subject of this study. Values of major chemical components as well as mineral nutrients, antioxidants and some vitamins of wholegrain flours obtained from white dent hybrid, yellow popping maize hybrid, red dent variety and blue popping maize landrace are presented. All flours had high fiber content (6.9-10.4%), while total protein ranged from 8.5% to 12.2%. A high level of anthocyanins was determined in blue popping maize wholegrain flour (910.0 mg CGE/kg), whereas yellow popping maize flour had a high content of total carotenoids (26.5 mg bCE/kg). Total antioxidant capacity was the lowest in white (15.50 mmol Trolox Eq/kg) and the highest in blue popping maize flour (37.6 mmol Trolox Eq/kg). All investigated wholegrain flours contained high levels of potassium and magnesium, as well as high content of trace elements, namely iron, zinc, copper and manganese. The maize flour is naturally gluten-free, which makes it highly suitable for persons susceptible to a gluten allergy and those with celiac disease. These results indicate that the wholegrain ZP maize flours can be used as functional food ingredients.

This study's primary objective was to assess the quality parameters of fifteen different genotypes of Serbian maize hybrids in order to establish whether they were suitable for making high-quality silage for ruminant feed. The study was carried out as a two-year field experiment at the Maize Research Institute in Zemun Polje, Serbia. Laboratory analyses included the yield structure of the examined maize hybrids, the evaluation of the composition of lignocellulosic fiber and the percentage of their ratios, as well as the in vitro dry matter digestibility and NDF digestibility of the whole plant samples. The Fisher's LSD test was used to statistically analyse the data, which were then reported as the mean and standard deviation of at least three independent replicates. The graphical representation of correlations among the observed parameters used the principal component analysis (PCA) method. All maize hybrids have displayed high-quality characteristics, which are required for the production of high-quality silage.

Information regarding the adaptation of maize (Zea mays L .) inbred lines to various field conditions and seed longevity is essential for seed companies. The objective of this work was to evaluate different vigour tests for detecting differences among naturally aged seeds and to assess the relationship between seed quality parameters and pedigree data of maize inbred lines. A seed of 15 maize inbred lines, selected at Maize Research Institute Zemun Polje, belonging to different heterotic groups was produced during 2011. Seed quality was assessed in 2015 by standard germination , radical emergence, accelerated ageing, and cold test. Root length of 4-day old seedlings was measured in all applied tests. Analysis of variance showed that genotype and storage conditions had a significant effect on all seed quality parameters. Large variation among inbred lines was detected in seed vigour determined by three tests, in particular by the accelerated ageing test. Cold test results showed very good chilling tolerance of tested genotypes, except two inbred lines with Lancaster background. The correlation between the cold test and the accelerated ageing test was significant, while the radical emergence test had a poor correlation with them. Obtained results indicate that the application of either cold test or accelerated ageing test is reliable for screening seed vigour of maize inbred lines.

Identification of high yielding and stable genotypes is one of the main goals in all breeding programmes. Estimation of hybrids is often aggravated due to the presence of genotype x environment (GE) interaction. One of the ways to eliminate negative effect of this interaction is the application of reliable statistical models such as AMMI model, which singles out high yielding and stable genotypes that have positive reaction to the improvement of production environments. This research aimed to establish specific maize hybrids interactions in different environments in two years by AMMI analysis. Twelve KWS maize hybrids belonging to FAO 400-500, were examined in two years over eight locations in Vojvodina. The highest yield in both years had the hybrid KWS2 (12.764 kg ha-1). Based on the AMMI1 model, hybrid KWS9 showed the highest stability and adaptability at all locations. According to AMMI2, hybrids KWS1, KWS3 and KWS12, had the highest stability and adaptability, while hybrids KWS2, KWS6, KWS8, KWS9 and KWS10 showed a satisfactory level of stability and it is necessary to pay attention to which locations they have positive interactions in order to be recommended in such regions. Nevertheless, based on the AMMI2, locations Temerin, Kikinda and Zrenjanin, showed similar interaction response, which points out that the number of trial locations could be reduced. Obtained results would contribute to the more precise decision in hybrids recommendation for the certain region, but also in defining further aims in maize breeding.

Taste and nutritional value make sweet corn a valued plant and an important component of the human diet worldwide. Kernel nutritive composition of sweet corn has been reported in various papers, but a description of carotenoid and tocopherols profile, especially after cooking is scarce. Therefore, the present study was carried out to compare the carotenoid and tocopherol content in sweet corn before and after cooking. Contents of b-carotene, lutein+zeaxanthin and tocopherols (d-T, b+g-T, a-T) in the kernels of twelve sweet corn hybrids were determined by High-Performance Liquid Chromatography (HPLC) and were expressed as the mean value of three independent measurements. Both genotype and cooking affected the content of the carotenoids and tocopherols in the kernel. The highest content of total carotenoids before and after cooking was found in hybrid ZP486/1su (27.77/45.28 µg/g) whereas the lowest content was in hybrid ZP 355su (10.27 µg/g) before cooking i.e. in hybrid ZP 347su (24.55 µg/g) after cooking. The cooking resulted in a significant increase in the content of total carotenoids and tocopherols, lutein+zeaxanthin, and b-carotene in all hybrids, except the ZP504su in which the b-carotene content decreased. An increase in a-tocopherol after cooking was observed in hybrids ZP485/1su and ZP484/1su, while a decrease was in hybrids ZP481/1su, ZP486/1su and ZP477/2su. The results showed that increasing micronutrient content is genotype-dependent. This study confirmed that cooking increases the nutritional value of sweet corn and gives it additional value in terms of functional food.

Five maize hybrids were used in this research: two yellow and one white dent, sweet hybrid, and yellow popcorn. Five brine recipes with acetic acid were examined, of which two with the addition of potassium sorbate. The brines with preservatives were stable for 16 months without colour changes of the liquid and corn cobs. The pH of brines ranged from 3.39 to 3.89. Canned hybrids ZP 366 and ZP 611k in brine without sugar, and with the addition of potassium sorbate and potassium metabisulfite marked as Number 5, showed the best sensory characteristics. The protein content determined in ZP 366 (9.56 %) and ZP 611k (10.23 %) did not vary significantly compared to whole-grain maize flour, while crude fibre content (7.67 and 6.88 %), and ash content (21.96 and 20.72 %) were significantly higher than in flour (crude fibre: 2.40; 2.64 %, ash:1.35; 1.48 %, respectively). This research will be continued in order to implement preliminary findings and new data on this subject.

The focus of this study is on the physical quality traits and starch composition of various maize kernel genotypes grown in Serbia. Furthermore, the aim was to determine the relationship among these quality traits. Results obtained from the Stenvert hardness test showed great variability among the maize samples. The portion of the hard endosperm fraction (HE) ranged from 53.29% to 76.28%. Test weight (TWt) and 1000-kernel weight (KWt) of 10 different ZP maize genotypes ranged from 782.69 to 907.39 kgm-3 and from 128.40 to 376.50 g, respectively. The specialty maize genotypes had the highest content of amylose (27.8% and 28.9%). Yellow dent genotype, ZP 606, had the lowest amylose content in the kernel (22.3%). The results suggested that the composition of starch granule differed depending on the hardness of the endosperm. The amylose content was highly correlated with the physical traits such as TWt, KWt, density and HE.

The protein content is an important parameter of the technological quality of soybean grain. Therefore, the selection work is aimed at creating a genetic basis for obtaining varieties not only of high yield but also varieties of improved grain quality. In order to provide sustained progress in breeding, it is necessary to find a stable source for breeding for desired traits. The aim of this study was to examine the value of the genotype × environment (G× E) interaction for protein content in 14 Maize Research Institute "Zemun Polje" short-season soybean accessions and to identify stable sources that can be used in breeding for protein content improvement. G×E interaction for grain protein content was analyzed using a linear-bilinear AMMI-1 model. The influence of genotype and environment on the total variation of protein content was approximately equal, while the smallest variation is attributed to genotype x environment interaction. A large number of genotypes with different protein content (Korana, PI 180 507, Kabott, Krajina, Canatto) showed a small contribution to the interaction in studied environments, the most important of which were genotypes with above-average protein content, as potential sources for future breeding programs.

Maize is one of the most important field crops both in the world and in our country. All commercially grown maize hybrids can be classified into one of five elementary types: dent, flint, floury, popping and sweet maize. The objectives of this study were to characterize the grain chemical compositions of yellow-seeded and white-seeded maize dents, popping maize and sweet maize genotypes. The results show that grains contents of starch, protein, oil, crude fibre, and ash of four selected maize genotypes ranged in the intervals: 53.54-68.13%; 9.19-13.00%; 4.35-5.39%; 2.13-3.93% and 1.28-2.85%, respectively. The amylose to amylopectin ratio varied from 21:79 to 28:72, which is a principal property of normal maize starch. The content of lignocellulosic fibres: NDF, ADF, ADL, hemicellulose and cellulose ranged from 11.31-15.27%; 2.51-3.54%, 0.24-0.52%, 8.10-12.68% and 2.14-3.02%, respectively. The solubility index of albumin, globulin, zein and glutelin ranged from 9.46-29.42%, 5.64-13.13%, 21.11-28.10% and 18.81-23.69%, respectively

Physical quality traits (1000-kernel weight, density, milling response and soft endosperm portion), basic chemical (starch, protein, oil, cellulose and ash) and amino acids composition of ten ZP maize genotypes differing in kernel hardness and colour were studied. The objectives of this study were to characterize differences in ZP maize genotypes regarding to various physical traits and nutritional quality parameters such as basic chemical and amino acid composition and the data was correlated to find the interrelationship between these parameters. Kernel physical traits and chemical composition significantly varied among tested genotypes. A significant negative correlation was found between protein content and portion of soft endosperm as well as a significant positive correlation between protein content and two physical traits, milling response and density. Protein content showed a non-significant negative correlation with starch content. The results showed that the protein content exhibited negative correlation with lysine as well as positive correlation with methionine. It has not been observed a significant improvement in the amino acid composition regarding the specialty genotypes such as the selected white and red kernels and popping maize genotypes. The information presented in this study could be useful for the utilization improvement of maize kernel and the development of maize-based ingredients to prepare nutritious feed and food products.

Sweet corn is considered as tasty and quality food. Its kernels contain sugars that are in good balance with amino acids, minerals and vitamin B. It is used as fresh product right after the harvest, but also for further industrial processing, freezing and canning. In breeding of sweet corn, equal attention is paid to the production of high and stable yielding hybrids, and to the enhancement of technological and sensory properties of the ear and kernel. The aim of this research was to establish agronomic and sensory properties of 12 sweet corn hybrids, 3 commercial and 9 experimental. The trial was set up according to the RCBD on two locations and in three replicates. The evaluation of agronomic parameters encompassed: fresh ear yield without husk, ear length, number of kernel rows and shelling percentage. Also, sensory characteristics were analyzed: appearance, color, smell, sweetness, juiciness, crispiness, pericarp hardness. Sensory characteristics were evaluated by voluntary panelists and scaled with 1 - 9 point hedonic scale. Fresh ear yield significantly varied over locations and hybrids. The highest fresh ear yield had experimental hybrid ZP 481/1su - 13.33 t ha-1, while the lowest was 7.14 t ha-1 (ZP504su). The difference between sensory characteristics among hybrids was also noticed, although all hybrids had satisfactory sensory characteristics with the average sensory marks above 7.30/9.00. The best sweet corn hybrid according to sensory characteristics was ZP 483/1su (8.29), while the highest yielding one ZP 481/1su had an average sensory mark 7.70.

Western corn rootworm (WCR) (Diabrotica virgifera virgifera LeConte) is one of the most important and potentially most dangerous pests of maize. Since its occurrence in Serbia in 1992, it has been present in almost all areas under maize cultivation. Alongside with all preventive measures, first of all, the crop rotation, which is considered the most economic one, a great attention has been paid to the forecast of the pest occurrence based on the flight dynamics and the population level. The flight dynamics, sex dominance, variations in the population level depending on the trap types and climate factors were observed on two locations: Crepaja in three-year continuous cropping (2005-2007) and in the experimental field of the Maize Research Institute, Zemun Polje in the duration of five years (2005-2009). According to the flight dynamics of WCR adults, the highest population level of this pest was observed in 2005, while the comparison of the number of adults over locations showed greater abundance of the pest in Crepaja than in Zemun Polje, which was attributed to extreme favourability of agro-ecological conditions on this location for the WCR development. The 2008-2009 period was characterised by the reduced number of WCR, which coincided with the extremely arid conditions that do not favour the development of this pest.

Maize hybrids (Zea mays L.) with specific traits, such as those with red pericarp, high-protein flints or white kernel hybrids, have increased utility value as they contain some vitamins and minerals beneficial to human and animal nutrition. Furthermore, their cultivation with the application of specific fertilisers could further increase the grain quality through increased participation of macro- and micro-elements that are lacking in the diet. Agronomic biofortification encompasses the application of different production technology that enables better absorption and effective accumulation of essential elements such as iron, zinc, manganese, copper in the edible parts of cultivated plants. On the other hand, fertilisation influences the weed infestation levels and especially the presence of nitrophilic weed species in maize crop. The fertiliser application changes the balance in competition between crops and weeds, not only for nutrients but also for other resources. The effects of different fertilisers were compared within developmental research in the field of ecological agriculture to point up the advantages of microbiological and organic fertilisers, since these fertilisers can contribute to higher yields, but unlike mineral fertilisers, they positively affect the soil and agro-ecosystem. The studies were carried out to determine to what extent agronomic biofortification contributed to the increase of yielding potential and grain quality of maize genotypes with specific traits, as well as how it affected the occurrence and distribution of weeds. The red kernel maize hybrid ZP5048C, high-protein flint maize hybrid ZP737 and white kernel maize hybrid ZP552b, were grown in variants with mineral fertiliser urea, microbiological fertiliser Team Micorriza Plus and organic fertiliser Fertor, that contained essential elements necessary for the nutrition of cultivated plants. No fertiliser was applied to the control treatment. The fertilisation mainly contributed to the increase of weed mass in comparison with the non-fertilised control variant in extremely dry 2017. The highest weed mass was recorded in the hybrid ZP737 in the variant with organic fertiliser, while the lowest weed mass was recorded in all hybrids when microbiological fertiliser had been applied. The highest, i.e. lowest grain yield was recorded in the hybrid ZP5048C (5.83 t ha-1), i.e. ZP737 (3.36 t ha-1), respectively. The protein content was increased at the highest extent in the kernel of ZP737 hybrid after the application of urea, while oil and starch contents were the highest in the grain of white kernel hybrid ZP552b treated with microbiological fertiliser. Due to the specificities and importance of meteorological conditions, the studies will be continued during the next few seasons. .

Twenty-six maize landraces were tested in order to evaluate maize seedling performance as an index for drought tolerance in adult plants. Samples were subjected to polyethylene glycol-induced osmotic stress at the early seedling stage. Grain yield was obtained in field experiments under well-watered (OC) and a combination of drought and high plant density (HD) conditions. Osmotic stress caused a reduction in seedling growth (length, fresh and dry weight), and increase in the shoot and in particular the root proline contents in the majority of landraces, and variations in root peroxidase (POD) activity. Genotypes displaying more pronounced root growth reduction and higher proline contents exhibited decreased POD activity under osmotic stress. Direct positive correlations between the proline content and growth inhibition, and between the proline and soluble protein content were established. Correlations between the changes in POD activity and growth parameters were significant and positive, and significant but negative with the changes in the proline content. In the field, water stress led to a reduction in grain yield in all of the tested landraces. Correlations between grain yield from both experimental sets (OC and HD) and osmotic-induced changes in seedling root growth were negative, which was opposite to the highly significant and positive correlations between the changes in the seedling root proline content and yield. Also, genotypes with the highest seedling root proline content increase under osmotic stress, exhibited the highest stress tolerance index (STI) based on grain yield achieved under both field conditions. Our results indicate that lower changes in POD activity and especially an increased proline content after exposure to osmotic stress during the early seedling stage could be considered as useful indices to facilitate selection efficiency for drought tolerance in adult plants. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR31028: Exploitation of maize diversity to improve grain quality and drought tolerance]

The influence of grain moisture content at harvest and at the moment of popping on popping volume and percentage of unpopped kernels was analysed. Four popcorn hybrids were studied. Hybrids were harvested when grain moisture content was: above 25%, between 20 - 25%, and below 18%. Each sample was popped at 20%, 18%, 16%, 14%, 12%, and 10% of grain moisture. All examined factors and their interactions significantly influenced both popping volume and percentage of unpopped kernels. The highest popping volume and the lowest percentage of unpopped kernels were observed at 14% grain moisture content. Hybrid ZP 608k had the highest popping volume and the lowest percentage of unpopped kernels at all treatments and overall. The lowest popping volume and the highest percentage of unpopped kernels were noticed for ZP 501k. The lowest percentage of unpopped kernels was observed in the last harvest term when grain moisture content was below 18%.

In plant breeding programs, it is often necessary to cross genotypes incompatible in time of flowering. In maize, when the incompatibility in flowering period could not be overcome by different sowing dates, or by the ability of silk to preserve its fertility in 10-15 days, conservation of pollen could be of great importance. For many plant species, the appropriate methods for pollen management have been set up, including methods of collecting, desiccation, testing of viability and longevity, as well as for pollen storage. The longevity of pollen during its storage depends upon plant species, conditions at the time of pollen collecting, pollen moisture content, as well as upon storage temperature and duration. Even within the same plant species, different genotypes exhibit different level of viability preservation during the conservation. Although maize pollen belongs to a tricellular pollen group and rapidly loses viability under field conditions, its preservation is possible. According to the literature, pollen viability could be preserved for 30 days in the conditions of refrigerator (+4°C), while in liquid nitrogen (-196°C) up to 120 days. In the majority of studies, pollen viability was evaluated in the laboratory conditions, and the results obtained could largely be differed from those obtained under field conditions, due to impossibility to control a number of environmental factors. This experiment was conducted under field conditions in order to evaluate the ability of pollen from commercial maize inbred line L217, stored under the conditions of +4°C and -20°C, to pollinate maize inbred L73B013 and produce grain. Inbred L73B013 is sown in five sowing dates in order to ensure the longer presence of fresh silk. Pollen samples from line L217 were taken twice, and along with silica gel, stored in refrigerator and freezer. Each of successive pollination included five silks. Except for the expected good ear seed set when silks were pollinated with fresh pollen, the next successive pollination resulted in extremely poor ear seed set. Pollen stored in the freezer for one day completely lost vitality, while the pollination with pollen stored for three days resulted in one kernel per ear (for two ears). Pollination with pollen stored for four days resulted in one kernel per ear for only one ear. Pollen stored at + 4°C gave slightly better, but still very poor results. Compared to control, the percentage of seed set for pollen stored only for one day was 4.4%, being decreased to 0.2% and 0.4% for pollen stored for four and five days, respectively. Plants pollinated with pollen stored for 20 days did not give any grain. Such poor results may be a consequence of species specific properties of inbred L217, but also a consequence of failure in the manipulation of pollen. A highly sensitive point during the storage of pollen, especially in species with pollen sensitive to dehydration, such as the maize pollen, is the process of drying before its storing. Therefore, we concluded that the procedure of pollen desiccation probably was not adequate. With the aim of correcting the deficiencies observed, the experiment will be repeated in 2017.

In this study 36 maize hybrids of different FAO maturity groups were observed in three successive years (2011, 2012 and 2013), on 8 locations. The main objective of this experiment was to observe the GxE interaction concerning yield, grain moisture, grain yield per ear and test weight. The experiment was set up according to the RCBD. Based on the obtained results average estimates, CV and overall ranking of hybrids were calculated. ANOVA was applied in order to estimate the effect of factors: genotype, environment and interaction. Thus the significance of all these factors was observed. Results of this research indicate the importance and necessity of performing multilocation and multiyear trials with the aim of observation and understanding the intensity of GxE interaction, as well as its influence on the grain yield and it components.

Sweet corn is used as food in the milky stage of endosperm, when its kernel is tender, succulent and sweet. It is consumed in form of fresh ears, or it is industrially processed. Breeding of sweet corn has several equally important aims that are directed by the market demands and different modes of consumption. The ear yield, in sweet corn is the most important but not the only main goal of breeding. In the two year study (2013, 2014) we observed the effect of the genotype, year and their interactions on the yields of 8 sweet corn hybrids. Two of the hybrids were commercial and six were experimental hybrids. The field experiment was arranged according to the RCBD with four replications. Hybrids were harvested 23 days after pollination, i.e. silking. Average yield in 2013 was significantly higher (12.19 t ha-1) than in 2014 (11.49 t ha- 1). In 2013 it ranged from 10.21 t ha-1 for the experimental hybrid ZP 489/1su, up to 13.52 t ha-1 for the commercial hybrid ZP 355su. In 2014 the lowest yielding hybrid was ZP 485/1su (10.14 t ha-1) while the highest yielding was ZP 486/1su (13.41 t ha-1). On average those two were also the highest (13.19 t ha-1) and the lowest yielding (10.66 t ha-1) hybrids. Statistical analysis showed that the effect of genotype and the year, as well as their interactions had significant impact on the yield performances of sweet corn hybrids.

During 2008 and 2009, efficacy of insecticidal products, based on thiamethoxam and imidacloprid, were tested. Furthermore, effects of entomophatogenic fungus Beauveria bassiana on the infestation intensity of European corn borer (Ostrinia nubilalis), were established over effects of both, 10 different treatments of maize seed (8 treatments and 2 controls) and the application of the fungal inoculum. Trials were carried out on maize crop under field conditions in accordance with the EPPO method. Results obtained in the studies with the product Cruiser 350 FS (350g l-1 thiamethoxam) applied in the amount of 0.9 l per 100 kg of seed and the products Imidor 600 FS and Gaucho 600FS (600g l-1 imidacloprid) applied in the amount of 0.7 l per 100 kg of seed, point out to satisfactory efficacy in controlling ECB and satisfactory effects on maize yields. The intensity of ECB infestation, expressed in percentages, ranged from 50.1% to 74.1%. The interrelation between average percentages of infested plants and obtained yields in both investigation years (2008-2009) in Zemun Polje was established. Results over treatments indicate that the highest percentages (62.2%) of infested plants were observed in the control variant (K1- Captan). Moreover, as expected, the lowest yield was also recorded in this variant. The treatment with the fungicide Maxim combined with the insecticide Criuser proved to be the most efficient. At the same time, the percentage of infested plants was the lowest in this treatment (53.32%) and the yield was the highest (8.610 t ha-1). The infestation level of maize plants in this treatment was significantly reduced over years of investigation in comparison with remaining treatments. Meteorological factors during the years of investigation, especially unfavourable agroecological conditions in 2009, affected the average yield of maize per hectare. The yield (8.314 t ha-1) recorded in the treatment with the inoculum of B. basssiana was almost equal to the one recorded in the treatment with the product Cruiser (8.610 t ha-1), while it was higher than the yield obtained in the treatment with the products Gaucho (7.506 t ha-1) and Imidor (8.259 t ha-1) combined with the fungicide Maxim. These differences were not statistically significant. Seed treatments with the fungal inoculum were not significantly different in any of observed parameters, except in the seed treatment with Captan. The comparison of data obtained in the two-year studies (2008-2009) under conditions of natural ECB infestation, shows prevalence of plants with damages of leaves (type H2) and tassels (type M3-4), which is indicated with the average score of 2.43. According to the average scores, it can be concluded that ECB infestation did not result in damages that would have significantly affected maize yield. In order to establish significance of certain observed parameters, they were compared and their correlations were determined. The greatest negative correlation with the 0.05 probability level (r= -0.96533) was established between the plant damage score and the recorded yield. Since recorded value of coefficients of correlation was approximately 1, it can be stated that the complete functional linear dependence existed among variables. Achieved results show efficiency of insecticides based on thiamethoxam and imidacloprid in the regulation of the infestation level in maize and also point to negative effects of the fungus B. bassiana on entomofauna of maize and its mycoinsecticide activity that could find an application in biocontrol of insect pests of maize.

Mineral elements deficiency in food can cause serious health problems. Being one of the three most importatnt macroelements for plant nutrition, phosphorus is involved in several key processes: photosynthesis, respiration, synthesis of starch, transport of carbohydrates and products of photosynthesis, cell division and increased water utilization. The objective of this study was to estimate the dynamics of inorganic phosphorus (Pi), as a precursor in the synthesis of phytic acid, and phytic phosphorus (Pphy) accumulation during the grain filling of two maize inbred lines differing in FAO maturity groups - L217 and L773. In addition, possible linkage between phosphorus content in grain and agro-morphological performances was observed. For the analysis of the dynamics in Pi and Pphy contents, seed samples were taken at 15th, 30th, 45th and 60th day after the polination. The obtained results showed a continuous decline of Pi content in both genotypes, with the most intensive decline observed at the first interval (e.i. 15-30 days) after the polination. The trend observed was much more pronounced in L217. Moreover, this inbred acheaved higher grain yield for 61.8 % at first sowing and for 63.1 % at 10-day delayed sowing, respectively, compared to inbred L773. In all three intervals observed, the decrease of Pi content was highly correlated with Pphy content increase for both genotypes. Based on lower accumulation rate, followed by lower Pphy content (2.635 mg g-1) during the stage of physiological maturuty, it could be concluded that inbred L217 could be considered as potentialy suitable genotype for low-phytic hybride selection.

This research encompassed a total of 12 popcorn hybrids planted according to the RCBD in three replicates in Zemun Polje in 2016. The following traits were analyzed: grain yield (t/ha), kernel size, 1000 kernel weight, popping volume, percentage of unpopped kernels, and sensory characteristics (the appearance, taste, smell, tenderness, crispness, adhesiveness to the teeth, presence of pericarp and overall taste acceptability of popcorns). The analysis of variance showed significant differences between the popcorn hybrids with regard to the traits analyzed. The grain yield ranged from 4.78 t/ha (ZP 644/1k) to 7.38 t/ha (ZP 557/1k). The lowest popping volume was noticed in ZP 501k (28 cm3/g), whereas the highest popping volume was found in the lower-yielding hybrid ZP 544/1k (40.17 cm3/g). The percentage of unpopped kernels was very low and it ranged from 0.66% to 4.57%. The analysis of sensory characteristics of popcorns also showed differences between 12 popcorn hybrids.

Cold test (CT) is a valuable method of assessing maize seed vigour. Although widely used CT is not standardized because of variations in CT procedures. The objective of this study was to evaluate seed vigour of 15 maize inbred lines developed at the Maize Research Institute Zemun Polje, using two different substrates (soil and sand) in a severe CT (7.5°C for 10 days followed by 7 days at 20/30 °C). Statistical analysis showed that inbred lines differ significantly in seed vigour, and no difference between two applied substrates in CT. Coefficients of variation were lower in CT with sand (6.05 %), compared to the CT with soil (6.74%) due to variation in soil quality and presence of soil-borne pathogens. Both CT procedures were highly correlated with field emergence. Results of this research indicate that CT with sand is appropriate for testing maize seed vigour, with the potential for standardization.

According to regional reports on climate, more frequent and severe droughts and floods are already apparent. Modern maize breeding for different purposes (e.g. drought tolerance) emphasizes the importance for improved maize ability to withstand adverse environmental conditions. Genotypes with drought tolerance obtain high grain yield under optimal conditions and lower, but stable yield under dry environmental conditions. Field testing was conducted in 2014, on twenty-three maize inbred lines differing in drought tolerance. The inbreds were evaluated in respect to morphological traits (plant and ear height, total number of leaves, number of leaves above uppermost ear, ear leaf length and width), yield components and grain yield per plant. The experiment was set up according to RCB design with two replications. To simulate water stress, two plant densities were applied. According to Principal Component Analysis and cluster analysis, five inbred lines (T1, T2, T4, T8 i T15) performed the highest stability in both experimental conditions. Those inbreds could be used as a source for drought tolerance in breeding programs.

This paper discusses the application of the infrared (IR) spectroscopy method for determination of structural properties of maize hybrid grains. The IR spectrum of maize grain has been registered in the following hybrids: ZP 341, ZP 434 and ZP 505. The existence of spectral bands varying in both number and intensity, as well as their shape, frequency and kinetics have been determined. They have been determined by valence oscillations and deformation oscillations of the following organic compounds: alkanes, alkenes, alkynes, amides, alcohols, ethers, carboxylic acids, esters and aldehydes and ketones, characteristic for biogenic compounds such as carbohydrates, proteins and lipids. In this way, possible changes in the grain structure of observed maize hybrids could be detected.

Popping maize is a specific type of maize differing from other types of maize by its capability to form a large puff or flake after explosive 'pop' that is a response to heating. Besides grain yield, an economically important trait, it is necessary that popping maize hybrids are characterized by a great popping volume and quality and testy flakes as well as other essential production traits. The grain yield of 12 selected popping maize hybrids was observed and the interrelationship among the grain yield, popping volume and the number of kernels per 10 g was established. Obtained results point out to a negative statistically significant correlation (-0,684*) between the grain yield and the popping volume. Furthermore, insignificant negative correlations (-0,135 and -0,399) were established between the grain yield and the number of kernels per 10 g and the popping volume and the number of kernels per 10 g, respectively. The traits observed in the present study are the quantitative ones, that is, their expression is determined by the greater number of genes and by environmental conditions. .

The percentage of moisture content at the moment of popping has the most significant impact on the popping volume of popcorn. In this research we observed the influence of the optimal moisture content of 14.2 % and lower moisture content (12, 10 and 8 %) on the popping volume of twelve popcorn hybrids. At moisture content of 14.2 % the highest popping volume was observed in ZP 611k (41.33 cm3/g). Four popcorn hybrids had very good popping volume of over 39 cm3/g and four hybrids achieved medium popping volume of 36-39 cm3/g, while three popcorn hybrids had unsatisfactory popping volumes below 36 cm3/g. Hybrid ZP 501k was the one with the lowest popping volume of 28.67 cm3/g. By reduction of percentage of moisture content in the grain, significant reductions in popping volumes were observed - in average 37.68, 27.97, 16.93 and 3.79 cm3/g, respectively. Analysis of variance showed that genotype, moisture content and their interaction had significant impact on the popping volume.

These experiments were conducted in the period 2003-2008 in Zemun Polje. Five hybrids were investigated in six sowing dates - on April 5th (Sd1), 15th (Sd2) and 25th (Sd3), and on May 5th (Sd4), 15th (Sd5) and 25th (Sd6). Three unfavorable years for the maize production were distinguished in this period: 2003 with 210.0 mm, 2007 with 290.1 mm and 2008 with 224.6 mm of precipitation; 2005 was moderately favorable, with 387.4 mm of precipitation. Two years were favorable for the maize production, both in terms of precipitation amounts and distribution: 2004 with 427.6 mm and 2006 with 417.1 mm. The highest average yield was achieved in Sd2 (11.21 t/ha - 100%). On the other April sowing dates, average yield was lower: on Sd1 - 11.04 t/ha (98.48%), on Sd3 - 10.97 (97.86%). The effects of the May sowing dates were significantly lower comparing with the Sd2: Sd4 - 10.53 t/ha (93.93%), Sd5 - 10.46 t/ha (93.31%) and Sd6 - 9.71 t/ha (86.62%). The highest yielding hybrid was ZP 684 (11.16 t/ha). These results doubtlessly point to the mid April sowing date as an optimum for maize in Serbia.