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The objective of this study was to investigate the influence of seed coat colour on the seed quality of four red clover cultivars (germination, dormancy (hard seeds), dead seeds and initial seedling growth (vigour)) produced in Serbia over a period of two years. The seeds analyzed were first separated visually into bright, dark and mixed seed groups, followed by subsequent digital colour measurements. The results obtained showed that the seed coat colour of red clover could be considered a good indicator of seed quality and seedling growth ability. The results furthermore showed that bright-coloured seeds of red clover cultivars indicated increased vigour and seed quality compared to other colours. The impact of the production area and year on the seed quality parameters was inconclusive. A high variability in hard (CV = 22.22 %) and dead seeds (CV = 40.18 %) was recorded between different seed lots of red clover. A lower variability was found in the germination parameter of bright- and mixed-coloured seeds (CV = 4.53 % and CV = 8.53 %). The seed coat colour could be an important factor in determining the quality of red clover seeds, potentially increasing germination simply by removing dark-coloured seeds.

The research on the effect of ecological conditions and cultivars on the yield components of potatoes was conducted in Badovinci (Western Serbia) during the period 2008-2009. The following potato cultivars were included in the experiment: early ('Cleopatra', 'Anushka' and 'Presto'), medium early ('Kuroda', 'Omega' and 'Dita'), and medium late ('Desiree', 'Roko' and 'Jelly'). The four-replicate field trials were set up using the standard methodology according to the random block design. 18TThe research results suggest that genotype (G) and ecological conditions (E) significantly affect all yield components of potatoes. In both years, the highest yield was recorded18T in18T the medium late variety 'Desiree'18T 18T(18T28.30 t ha־¹), followed by the early variety 'Anushka' 18T(18T26.60 t ha־¹), 18Twhile the lowest18T 18Tyield18T was 18Trecorded18T 18Tin the medium early variety 'Omega' (18T13.35 t ha־¹). The 18Tresults obtained show that18T 18Tthe18T 18Thighest yields18T in Western Serbia were 18Trecorded in early varieties18T 18T('Cleopatra'18T, 'Anushka' 18Tand18T '18TPresto'18T) and 18Tmedium18T 18Tlate varieties18T 18T('18TDesiree'), which exhibited considerable18T resistance to high18T 18Tair temperatures18T and 18Tdrought stress18T.

Forage Sorghum is an annual herbaceous plant of the family grass. It is grown for feeding animals and people, and ranks among the millet grains. I disorders, sorghum is used as hay and to extract the starch, alcohol and glucose. Purpose of our paper is to determine which of the forage sorghum hybrids, among foreign selections, gives the best production results in the specific agroecological conditions on PSS Sremska Mitrovica experimental field and what are the possibilities of its use in our country. Five intraspecies hybrids (Sorghum bicolor x Sorghum bicolor) and two intraspecies hybrids (Sorghum bicolor x Sorghum sudanense) were analyzed in this paper. The difference in yield between the H7 hybrid that had the highest yield and H5 runner-hybrid was even 19 t ha-1, which indicates exceptionally high yield potential of H7 hybrid in biomass production. In specific agroecological conditions H7 hybrid gave the 96 t ha-1 of green fodder and 25.2 t ha-1 of dry matter.

Owing to its characteristics, alfalfa (Medicago sativa L.) is the most important forage plant in our country. The great importance of alfalfa is reflected in the production of high-quality fodder and alfalfa seeds, which are a valuable and competitive commodity on domestic and foreign markets. In this study, the presence of plant pathogenic genera of fungi on the seeds of five different alfalfa cultivars was investigated (Kruševačka 28, NS-Mediana, Zaječarska 83, Banjalučanka i Osječka-66) from three different lots (sites) of each cultivar. The detected phytopathogenic fungi on the alfalfa seeds caused a decrease in the overall germination, but the present research results indicate a satisfactory health status of all alfalfa cultivars and seed lots.

A field study in central Srem (Serbia) evaluated during two seasons the effect of nitrogen (N) fertilizer application (50, 100 and 150 kgha-1) and harvest time (from 70 to 110 days after the seeding) on fodder kale quality. Fodder kale was sown as a second crop in the conditions of irrigation. The goal of study was to evaluate the most important parameters of fodder kale quality (raw proteins and raw cellulose) depending on different nitrogen fertilization and harvest time. The average crude protein content increased (20.78-22,85 %) and the crude cellulose content decreased (15.12-13,96 %) as the nitrogen rates increased, directly due to the higher adoption of nitrogen and indirectly, by increasing the proportion of leaf dry matter in the total yield. The plants used in the first time of harvest had the highest leaf proportion and the highest protein content. Such trends changed in the last harvest time (by postponing the usage) when the crude cellulose content increased because of the leaf biomass reduction. The highest crude protein content (23.10 %) and the lowest crude cellulose content (13.63 %) in the fodder kale dry matter were obtained in the first harvest time (70 days after the seeding) using the highest nitrogen rate (150 kgha-1).

This paper presents the germination three cultivars of alfalfa using different concentrations of PEG-6000 (Polyethylene glycol) and control. The aim of this study was to determine the tolerance of alfalfa under drought stress effects and the choice of optimal testing methods. Seed germination and establish the presence of hard seed alfalfa was done by the standard method without pretreatment and with pretreatment. Readout germination of alfalfa seeds was done after ten days, according to the Rules for testing seed quality of agricultural products. The concentration of PEG of 0.4 MPa has proven to be optimal for assessing the seed germination of alfalfa. The alfalfa cultivars have behaved differently towards different concentrations on PEG, indicating the possibility of correct selection of alfalfa cultivars for autumn sowing period (September) after seed harvest in August.

Investigation of the influence seed tuber size and seed tuber pre-treatment on the total yield of early potato varieties Cleopatra conducted in Badovinci (western Serbia) during the 2007 and 2008 year. Examination were carried out by planting tuber weight 40 ± 5g, 60 ± 5 g i 80 ± 5 g. The research results indicate that the seed tuber size and pretreatment very significantly affected on all investigated characteristics potatoes. In both years the highest yield of tubers was established in the variant with the application of pretreatment and planting of the largest seed size fraction mass (80 g). Higher yields of potato tubers in moist conditions in western Serbia (Macva) of early varieties Cleopatra were achieved by planting larger mass of tubers (80 g) and removing the apical sprouts on tubers.

After harvesting, the seed dormancy of grasses occurs. During the maturing period, seed dormancy is slowly reduced, and seed germination reaches the maximum values of use. Germination decreases during longer storage. The levels of seed dormancy and germination prevention determine the complex of physiological and biochemical processes in the seeds, which vary depending on genetic background, environment during maturation, and even the position of seeds on the plant. The goal is to maintain, as long as possible, the maximum germination after seed ripening. However, aging and germination reduction are processes which largely depend of storage conditions and seed packaging. The three tested seed lots of tall fescue were kept in paper, textile and polyethylene (PVC) containers during 10, 16, 24, 28, 34 and 40 months. The dormancy, germination energy, and total germination were examined. The seeds stored in PVC containers required a shorter period of time in order to release from dormancy and achieve maximum germination (16 months, 43% germination). After 40 months, there was a significant decrease in germination (80%). In some seed lots, the germination dropped to 77%, which is the required minimum for marketing authorization (The Official Gazette of the Republic of Serbia, No. 47/48). In the case of the seeds kept in paper containers, the maximum germination (89% and 90%) was obtained after 22 months. The same seed germination was obtained after 40 months of storage.

After the harvest of tall fescue seed dormancy is present, indicating the reduction of germination. In conventional storage conditions for seed storage, we investigated the influence of three different ways of packaging (paper bags, canvas bags and plastic bags) to change the germination of seeds immediately after harvest, after 30, 60 and 90 days. After 30 days seed dormancy is reduced by 1 to 3% and germination was increased by 2-3%, while the impact of packaging had no significant effect. The decreasing trend in seed dormancy and increased germination even after 60 days continued in the same percentages. After 90 days of storage the contents of dormant seed was reduced to 22-35% and germination was increased to 65-72%.