EXAMINATION OF EARLINESS OF AUTOCHTHONOUS POPULATIONS OF PERENNIAL RYEGRASS
University of Montenegro
Monitoring of changes in phenological phases of autochthonous populations of perennial ryegrass was conducted on the experimental field of the Agricultural Institute of Republic of Srpska in Banja Luka (Bosnia and Herzegovina) during 2007, 2008 and 2009. Seven autochthonous populations collected in Bosnia and Herzegovina (BiH) and one variety of perennial ryegrass were used for this research. This research included the following populations of perennial ryegrass: Dragočaj, Kosjerovo, Laminci, TAS, Kupres, Maglajani, Manjača and variety Maya. The aim of this research was to select populations of perennial ryegrass in the conditions of opened pollination on the basis of phenological observations. These genotypes should be selected on the basis of earliness, length of vegetation and other characteristics important for understanding the initial genetic materials included in the breeding program of forage crops. During the research, the following changes were observed in phenological phases with the perennial ryegrass: growth of generative shoots 10 cm above the ground, the length of the vegetative phase from April 1, the period from heading to start of blossoming, duration of blossoming, and the length of the growing season. Phenological phases were observed individually by recording the date of their beginning and/or ending, and duration of the phases was expressed in number of days. On the basis of the duration of particular phenological phases, the differences were observed among autochthonous populations of perennial ryegrass in duration of vegetation period until appearance of spiking. The earliest ear formation was determined in population Laminci with the average duration of vegetative period of 29 days. Population Manjača had the longest period until the ear formation, which lasted for 44.9 days. During these tests of the duration of the vegetation period, three groups were distinguished. The first group, characterized with a shorter vegetation period, included populations: Laminci (82.5 days), Maglajani (84 days) and Kupres (84.3 days). The second group with the vegetation 2 period from 87-89 days included populations: TAS, Kosjerovo and the variety Maya. The latest maturing group included populations: Dragočaj and Manjača with the average duration of vegetation period of 95 days.
perennial ryegrass, populations, phenological phases, earliness, vegetation period.