| dc.description.abstract | This thesis reports on experimental work carried
out on sunflower (Helianthus annuus) over two seasons;
short rains of 1984 and long rains of 1985 at the Faculty
of Agriculture Field Station of the University of Nairobi,
Kenya. The Field Station is located at an altitude of
1850 metres above sea level and has an average rainfall
of 925 millimetres. The rainfall recorded in the two
seasons was 489.7 mm for the short ralns and 631.4 millimetres
for the long rains.
The main objectives of the experiment were to
find the effect of Towspacing, plant population and planting
date on yield, yield components and oil content.
The experiment was carried out in a split plot
design with dates of planting as main plots and rowspacing
and plant population as subplots. The difference between
the first date of planting was two weeks while the difference
between the second date of planting and third date
of planting was three weeks. The rowspacings used were
30 cm and 90 cm while the plant populations used were
25,000, 50,000, 75,000 and 100,000 plants per hectare.
The following were the subplot treatments which came out
after working out the plant-plant spacings; 90 x 11 (100,
000 plants per hectare), 90 x 15 (75,000 plants per hectare),
90 x 22 (50,000 plants per hectare), 90 x 44 (25,000 plants
per hectare), 30 x 33 (100,000 plants per hectare), 30 x
44 (75,000 plants per hectare), 30 x 66 (50,000 plants per
hectare) and 30 x 133 (25,000 plants per hectare). All
these subplot treatments were replicated three times in
the three main plots.
The results were as follows;
(i) Delay in planting by five weeks caused a reduction
in seed yield of 30% - 40% but an increase
in oil content. It also caused a signific~nt
reduction in the yield components.
(ii)
(iii)
(iv)
The increase in plant population from 25,000
plants per hectare to 100,000 plants per hectare
had no significant effect on seed yield but reduced
the yield components. The plant populations
of 50,000 and 75,000 had significantly higher
oil content than 25,000 and 100,000 plants per
hectare.
Increasing rowspacing from 30 cm to 90 cm had
no significant effect on seed yield and yield
components but had a significant effect on oil
content in one season only.
There was no interaction among planting date,
plant population and row spacing. | en |
