Savo Vučković

The effect of vegetation area size on grass seed yield

This paper surveys sowing norms (row spacing and seed rate) in both our country and the world, as well as the optimal seed rates in grass seed production. It gives a short overview of row spacings and seed rates applied in our and some other countries. Earlier, grass cultivated for the purpose of seed production was grown on small vegetation area. According to some researches, high seed yields can be achieved by cultivating grass on large vegetation area. Based on the results obtained, it can be concluded that the highest cocksfoot, timothy, meadow fescue, tall fescue seed yield was achieved with plants grown in 50 cm spaced rows employing lower seed rates (8 and 4 kg/ha of seeds). The highest Italian ryegrass and perennial ryegrass seed yield was achieved with plants grown in 20 cm spaced rows employing 20 kg/ha of seeds.

Response of Italian ryegrass seed crop to spring nitrogen application in the first harvest year

-1 . Tiller length was not affected by nitrogen application, while two other tiller parameters were much more affected by the treatments. The maximum seed yield in the first production year varied among treatments depending on season conditions. Harvest characteristics were impacted by nitrogen application; however, there was an opposite impact in arid and humid weather conditions. The N application of 50 kg ha -1 was found to be the optimal for seed production in those conditions. Higher rates of N application (100 to 150 kg ha -1 ) had either no impact on seed yield, or decreased the yield of seed as a result of ryegrass lodging following seed shedding. Abundant shoot dry matter was obtained in some treatment variants, but there was no linear correlation between seed yield and yield components.

Evaluation of inbred lines as sources of new alleles for improving elite maize hybrid

Choice of an appropriate donor of alleles for use in reselection programs of existing inbred lines of maize ( Zea mays L.) is crucial to the success of such programs. Well-adapted local inbred lines might be used as donors to improve a target genotype. The objectives of this study were to: (i) evaluate Serbian maize inbred lines as donors of favorable alleles for improvement of a single cross hybrid and (ii) estimate Dudley’s relationship values to determine which inbred parent should be improved.Evaluation of four donor lines as sources of new favorable alleles for the yield of grain yield not present in the elite hybrid parent line was conducted, (Dudley, 1987a; 1987b). Each of the potential donors had significant values of the parameter μG, so they can be used as the sources of new alleles in the improvement of elite hybrid A654 × Fu4 yield. The greatest number of favorable new alleles for the improvement of grain yield of hybrid A654 × Fu4 was recorded in inbred line ZPLB368. The improvement of yield ...

Morphological and Nutritional Properties of Birdsfoot Trefoil (Lotus corniculatus L.) Autochthonous Populations in Serbia and Bosnia and Herzegovina

Birdsfoot trefoil (Lotus corniculatus L.) is a highly variable and widely distributed Old World perennial forage legume found in wild and naturalized populations throughout temperate regions of Europe, Asia Minor, North Africa, North and South America, Australia, and New Zealand. Understanding the relationships among birdsfoot trefoil morphological, ecogeographic and chemical characteristics may provide insights for better utilizing of exotic germplasms. Ten birdsfoot trefoil populations were and sampled and determined in Serbia and Bosnia and Herzegovina. Some morphological properties, such as growth form of populations, flower color, flowering period, number of stems, length of main stem, number of racemes per stem, number of flowers per inflorescence, number of pods per racemes, number of seeds per pods, hard seeds in the first year, dry matter (DM) yield, and some chemical properties, such as content of crude protein, ash, fat, crude fiber, phosphorus, calcium, magnesium, potassium, K/(Ca+Mg) ratio, and sulfur, manganese, iron, copper, zinc, selenium and tannin contents, were determined in all populations. Serbia is an important origin center of genes for many legume species. Considering the high values of their traits, some Serbian trefoil populations could serve as a valuable breeding material. In comparison with populations from other parts of the world, Serbian populations are superior in chemical properties and nutritional quality values. The investigated populations clustered in two distinct groups according to the analyzed characteristics.

FORAGE QUALITY AND ENERGY CONTENT OF PERENNIAL LEGUME-GRASS MIXTURES AT THREE LEVEL OF N FERTILIZATION

The aim of this study was to investigate fodder quality and nutritive value of different grass-legumes mixtures influenced by various level of N fertilization. Studied factors had an impact only on the content of crude protein (CP), crude protein yield (CPY) and nitrate content in the forage. The level of N fertilizer showed a highly significant and positive impact on the CP and nitrate content. Treatment with 210 kg N ha-1 is characterized by the highest content of CP and nitrate of 189.7 g kg-1 DM and 2524 ppm, respectively, and the highest protein yield of 1.95 t ha-1. The value of nitrate in the forage does not exceed the limit that is considered hazardous to the health of animals. Energy value of forage obtained from the grasslands of ME ≈7.75 and NEL≈4.32 MJ kg-1 DM is lower than values obtained in other studies. [Projekat Ministarstva nauke Republike Srbije, br. TR-31053]

Yield potential and quality of forage mixtures of alfalfa with cocksfoot and tall fescue depending on the nitrogen fertilization.

The study was performed at the Institute for Animal Husbandry in the three year period, in field and laboratory conditions. The experiment involved two mixtures of grasses and legumes: mixture A ( alfalfa (cv. K -28 ), 50% and cocksfoot (cv. K-40 ), 50% ) and mixture B (alfalfa (cv. K -28 ), 33.3 % , cocksfoot (cv. K -40) , 33.3 %, and tall fescue (cv. K -20) , 33.3 % ), and pure stand of alfalfa (M). The experiment was conducted in a randomized block design with four replications. Fertilization was carried out using the split method, in quantities of of 0, 70 and 140 kg N ha -1 . The aim of this study was to determine the phytocoenological stability of mixture of alfalfa (Medicago sativa L.) with cocksfoot (Dactylis glomerata L.) and tall fescue (Festuca arundinacea Schreb.), the yield and quality of fodder obtained from the grassland, depending on the mixture composition and nitrogen fertilization. Studied factors had a statistically significant impact on dry matter yield and protein yield. Alfalfa has achieved significantly higher yields compared to its mixtures. Dry matter yield increased with the addition of N fertilizers. Protein yield was highest in pure alfalfa crop, followed by its mixture cocksfoot. Fertilization has also increased protein yield.

APPLICATION OF FARMYARD MANURE IN GRASSLAND PRODUCTION

This experiment aimed at determining the effect of farmyard manure (FYM) applicationon a natural pasturein Western Serbia, with a 30 t ha-1treatment in comparison to control (no fertilizer added) during two years (2012-2014).The FYM was applied in the autumn of 2012 and the trial plots were harvested twice a year. Dry matter (DM) yield and forage quality - content of crude protein (CP), nonprotein N (%CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and net energy for lactation(NEL), were estimated for each production year. Treatment with manure gave a higher DM yield compared to control plots in both experimental years (5.91 t ha-1 vs. 3.01 t ha-1 in 2013, and 2.76 vs. 2.03 t ha-1 in 2014). As expected,the yield in the second cuts of both years was much lower than in the first cuts. The FYM application did not affect chemical composition and net energy concentration of forages, whereas significant effects of different cuts were found, but were inconsistent between the first and second experimental year. In general, it can be concluded that application of FYM did not have a significant effect on forage quality ina permanent grassland, whereas chemical composition was significantly affected by different cuts and experimental years. Based on the results, a grassland may have a good DM yield response if FYM is used as a fertilizer, while the effect on forage qualitymay be much weaker.

Yield and morphological traits in alfalfa varieties of different origin

The study was conducted to examine variability of green forage yield (GFY) and morphological traits (tiller length, internodes length, internodes-stem diameter, leaf width and length) in nine alfalfa varieties from USA and six varieties from Europe. The trials were carried out in Central Serbia during the second (2006-A1) and third year (2007-A2) of alfalfa exploitation. In unfavourable environmental conditions (A1), varieties from the USA had higher coefficient of variability (CV, %) in all cuttings (I CV=16.93, II CV=17.13, III CV=13.00, IV CV=21.29), as well as total yield variability (CV=14.33), compared to varieties from Europe (I CV=7.45, II CV=6.47, III CV=10.65, IV CV=19.51, for total yield CV=6.43). In the favourable agro-ecological conditions (A2) genetic potential of varieties was manifested, which caused similar yield variability. Variety origin (USA or Europe) had a low effect on variability of the morphological traits. The highest correlation (P £ 0.001) was achieved between yield and tiller length, regardless of variety origin.

Optimising Stand Density and Nitrogen Fertiliser Rates for Seed Production in the Tetraploid Italian Ryegrass Cultivar K29T

Tetraploid cultivars of Italian ryegrass have been developed and used as an alternative to diploid cultivars in an attempt to improve forage yield and quality. But, very often, production of tetraploid cultivars is reduced by unfavourable weather conditions. The objective of this research was to determine seed production stability of the tetraploid Italian ryegrass cultivar K29T in variable and contrasting environmental and meteorological conditions in Serbia. The study was conducted in four consecutive years and generations of seed multiplication. Every year, seed was harvested from the primary growth in the first production year after the year of establishment. Data of investigated traits (heading and harvest dates, tiller length, number of spikelets per spike, seed yield, dry herbage yield and 1,000 seed weight) were recorded for different management practices (stand densities and nitrogen applications). It was determined that seed yield, dry matter production and tiller length were presumably most affected by different environmental factors in different production years, and different management practice, especially different sowing densities. In contrast, number of spikelets per spike and 1,000 seed weight were less affected by management practice, except in the extremely arid 2003 year. Variation in seed yield was more related to variation in seed numbers than to variation in seed weight. In the first seed production year, the best density in this experiment was 15–20 kg ha−1 of seed sown at an interrow spacing of 60 cm without fertilizing or with only 50 kg ha−1 of N. Therefore, seed of tetraploid Italian ryegrass cv. K29T can be produced in diverse environmental conditions in Serbia, but lower stand densities allow for better plant tillering and the production of a greater volume of seed and, at the same time, good dry matter yield of the residual biomass.