INFLUENCE OF SEED SIZE ON GERMINABILITY, GERM LENGTH, ROOTLET LENGTH AND GRAIN-YIELD IN SPRING OAT

During 1996, some laboratory tests have been conducted to determine th e influence of seed size in spring oat (variety VESNA) on the germinab ility, germ length and rootlet length. Also, field trial has been cond ucted to determine the influence of seed size on the grain yield. Seed calibration has been performed and seed fractions (mm of diameter) as follows: 2,8; 2,5; 2,2 were analysed; as well as unsieved seed as a c ontrol. The seed fraction of 2,8 mm has had the largest values of germ inability (99%), further the seed fraction of 2,5 mm and unsieved seed (97%), whereas the lowest values were attained with the seed fraction of 2,2 mm (95%). The differences in germinability found between seed fractions have been statistically very significant (P < 0,01). Similar results were also achieved with the seed size influence on germ lengt h and rootlet length. Seed fraction of 2,8 mm had the largest values o f germ length (8,3 cm) and rootlet length (9,8 cm), whereas the lowest values were attained with the seed fraction of 2,2 mm, respectively ( germ length 6,5 cm and rootlet length 8,0 cm). The found differences i n germ length and rootlet length between seed fractions have been stat istically very significant (P < 0,01). The greatest grain yield of spr ing oats were attained with the seed fraction of 2,8 mm (4,467 t/ha), and the smallest grain yield with the seed fraction of 2,2 mm (3,376 t /ha). The found differences between seed fractions have been statistic ally significant (P < 0,05).