Material and method Directory UMM :Data Elmu:jurnal:E:European Journal of Agronomy:Vol12.Issue1.Jan2000:
70 M. Pospisˇil et al. European Journal of Agronomy 12 2000 69–78
parison with areas under other field crops. This is split-plot method in five replications. Cultivar
OS-Nada, its mother 2n=18 and father 4n= the main reason why there are very few profes-
sional or
scientific studies
from this
area. 36 lines, were used as test crops. The ratio of
mother and father components at sowing was Researchers from North America Campbell,
1968, the UK and Denmark Scott, 1968; 6:0:2. Basic fertilization for seed sugar beet was
carried out with 50 kgha of N, 150 kgha of Longden and Scott, 1973; Longden, 1974 con-
ducted research with twice as many plants P
2 O
5 , and 300 kg ha of K
2 O. Sugar beet was
sown at the end of August at a between-row 300 000 plantsha at harvest as commonly
recommended in
other production
regions. spacing of 50 cm and within-row spacings of 11.4,
8.6, 7.1, and 5.7 cm. In spring, a density correction Trogisch 1985 maintains that a plant density of
150 000–250 000 plantsha at harvest is desirable was made according to the test treatments.
Leaf area per plant and the LAI were deter- for seed sugar beet grown under European condi-
tions. Under
the conditions
prevailing in
mined in characteristic pheno-stages of seed sugar beet at the start of vegetation in spring, in the
Vojvodina FR Yugoslavia, the highest yield and best seed quality of sugar beet were obtained with
stage of inflorescence stalk appearance and in full flowering using the punch method Campbell and
plant densities of 130 000 to 150 000 plantsha after wintering Stefanovic´, 1987. Based on the trial
Viets, 1967. In the said stages, measurements were made on ten plants from each treatment and
results achieved in eastern Slavonija Croatia, Kristek and Matic´ 1984 concluded that good
involved the number of leaves, the leaf weight per plant and their dry matter. Leaves with blades
yields might be obtained with 65 000–80 000 plantsha at harvest. According to the authors,
longer than 2 cm were counted. All observations and measurements in the trial were carried out on
nitrogen rates applied with topdressing to direct- drilled seed sugar beet vary, depending on the soil,
mother plants. Seed sugar beet was harvested at the end of July. Seed yield and quality were
from 150 to 250 kgha Longden and Johnson, 1977; Zarisˇnajak and Sˇijan, 1991; Rastija, 1993.
determined after the harvest. The data obtained were processed by up-to-date statistical methods
The objective of this research is to determine the effect of plant density and nitrogen application
analysis of variance, correlation applying com- puter programs Microsoft Excel 5.0 and Mstat.
upon the formation and size of leaf area, LAI, yield and quality of sugar beet seed. Investigations
Analyses of weather conditions during three growing seasons showed considerable variation in
should also reveal how much the yield and quality of sugar beet seed depend on the LAI.
precipitation distribution from year to year Fig. 1. Particularly unfavourable precipitation
distribution was recorded in 1991–92. Water balance after Thornhwaite’s method indicates a