|Abstract or Summary
- Five newly released and two Eastern European winter wheat
cultivars were grown under five different seeding rates (80, 160,
240, 320, 400 seeds per m²). Four of these newly released cultivars
were grown at three different locations which have different environmental
conditions. Data were obtained on grain yield, tiller number
per plant, 1000 kernel weight, seed number per spike, plant and
spike number per unit area, plant height, heading and maturity dates.
At the lowest rate of seeding the grain yield was significantly
lower at all three locations. Although there were no significant
differences for grain yield for all the other seeding rates, maximum
yields were obtained from lower seeding rates at Ryan while at
Hyslop and Madras, which had better moisture conditions, maximum
yields were obtained at higher seeding rates. This situation was not observed for the Yamhill cultivar in which maximum yields were
obtained at 160 seeds per m² seeding rate at all three locations.
Tillers per plant value decreased as the seeding rate increased.
Hyslop and McDermid produced significantly higher number of tillers
per plant from the other cultivars.
Significantly highest 1000 kernel weight values were obtained
at the lowest seeding rate. Yamhill produced the highest significant
1000 kernel weight while Paha produced the lowest.
Seeds per spike value followed the same order as tillers per
plant and 1000 kernel weight showing a continuous decrease with the
increased rates of seeding.
The number of plants per m² was a direct linear function of
seeding rate. The number of spikes per m² increased curvilinearly
with the increased seeding rate. Hyslop and McDermid produced the
highest significant number of spikes per m² because of their higher
Plant height increased with increased rates of seeding because
of the increased competition for light. Yamhill and Paha were
significantly the tallest cultivars. The tallest plants were observed
There was a decrease in the number of days in heading and
maturity as the rates of seeding increased. The cultivars ranked in
the order Paha > Yamhill > Hyslop > McDermid for heading and maturity dates. Heading first occurred at Hyslop followed by Ryan
and Madras while maturity occurred first at Ryan followed by
Hyslop and Madras.
Highly positive correlations were observed among plants per m², spikes per m and seeding rate while these factors correlated
negatively with tillers per plant, 1000 kernel weight and seeds per
The regression equations showed that maturity date, heading
date and spikes per m² values were the most important factors for