M. Flasarova et M. Onderka, FORMATION AND COMPENSATION OF YIELD COMPONENTS IN CHOSEN SPRING BARLEY GENOTYPES, Rostlinna vyroba, 43(9), 1997, pp. 449-454
In 1989, 1990 and 1991, formation, reduction and compensation of yield
components in chosen spring barley genotypes (Galan, Akcent, Ladik, H
eran) were quantitatively analysed at decisive stages of organogenesis
and under different environmental conditions: weather conditions of t
he year and N-fertilization (60 and 90 kg of pure nutrients per 1 ha).
A basic method used for statistical estimation was analysis of varian
ce of two-fold classification with replications. The Tukey test was us
ed to verify differences between individual mean values of variants. T
he objective of the study was to characterize formation, reduction and
compensation of yield components in different spring barley genotypes
, and to determine effects of increased N-rates on formation and utili
zation of yield potential. Data on characteristics of investigated gen
otypes are given in Tabs I and II. The genotype Galan showed lower til
ler formation, however, a high percentage of their fertility. It had b
oth high potential and actual spike productivity. The genotype Akcent
developed a high number of tillers, however, intensity of their format
ion was lower at the earliest growth stages and tillers were considera
bly reduced. It produced an average number of florets and kernels per
spike and reached a low kernel weight. The genotype Ladik exhibited lo
wer intensity of tiller formation and a number of the tillers was less
reduced. It produced a high number of florets per spike which was, ho
wever, strongly lowered. It was characteristic by a high kernel weight
. The genotype Heran showed intensive tillering and developed tillers
were considerably reduced. It had a low number of both florets and ker
nels per spike. A spike weight was higher. These results prove that wi
th regard to breeding for production potential genotypes with both hig
h yield potential and its realization are suitable. Weather conditions
of the years influenced the plant growth and development, and associa
ted processes of formation and reduction of yield components (Tabs III
and IV). The early growth stages were very important; they influenced
a number of tillers and, based on the intensity of their formation, a
lso productive density of the stand. At higher intensity of tiller for
mation till stage V of organogenesis a spike number per unit area incr
eased. The increase was, however, insignificant. Not only a number of
founded florets but as well as their reduction was decisive for a kern
el number per spike. There was no relationship between a number of dev
eloped florets and a final kernel number per spike. Yield differences
were caused by spike productivity, and especially by kernel weight. Ef
fects of nitrogen on formation and reduction of yield components are p
resented in Tabs V and VI. Under intensive conditions of the sugarbeet
growing region, after sugarbeet as a forecrop, an increased N-rate (9
0 kg.ha(-1)) improved potential stand productivity (tiller and floret
formation), but did not significantly affect its sink. It significantl
y decreased kernel weight and thus spike productivity and grain yield.