Effect of genotype plant population and nitrogen fertilization on growth yield and quality of sunflower (helianthus annuus l.) grown under semi-arid conditions oF Central Tanzania
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Date
2002
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Sokoine University of Agriculture
Abstract
Field experiments were conducted at Msalato and Makutupora during the 2000/2001
cropping season to evaluate the effect of genotype, plant population and nitrogen
fertilizer on growth, yield and quality of sunflower (Helianlhus annuus L.) grown under
semi-arid conditions of central Tanzania. The experimental design was a split-split plot
in randomized block with three replications. Two sunflower genotypes (The Open
pollinated-Record variety and CRN 1435 a hybrid) were assigned to the main plots.
three plant populations namely 55 555 plants ha'1 (60cm x 30cm), 44 444 plants ha'1
(75cm x 30cm) and 37 037 plants ha'1 (90cm x 30cm) constituted the subplots. Four
levels of N fertilizer (0. 30, 60 and 90kg ha'1) were allocated to the sub subplots. Record
variety (OP) produced significantly (P<0.05) taller plants, higher above ground biomass
and larger seed size than CRN 1435 (hybrid). Plant spacing had no significant effect on
plant height and dry matter accumulation. However, wider spacing recorded larger heads
and higher dry matter production than narrow spacing. Nitrogen levels did not show
significant effects. High values of dry matter accumulation were associated with high
levels of N application. The hybrid CRN 1435 significantly (P<0.05) recorded higher
number of seeds head'1, percentage oil concentration, seed yield and total oil yield (kg
ha'1) than Record variety. Head diameter, number of seeds head'1, seed weight head'1
and one hundred seed weight were the yield components significantly (P<0.05)
influenced by plant population. Percentage oil concentration, seed and oil yield (kg ha'1)
were significantly higher at high plant population (i.e. at a space of 60 x 30cm). Nitrogen fertilizer did not record significant difference in terms of seed yield and yield
components. The interaction between genotype and plant population was significantly
recorded for yield components like head diameter, seed weight head'1 and one hundred
seed weight with the highest values being recorded at 90 x 30cm spacing. Percentage oil
concentration, seed and oil yield were significantly highest for CRN 1435 at 60 x 30cm.
The hybrid CRN 1435 also produced more number of seeds, seed weight head'1.
percentage oil concentration, seed and oil yield at 60 and 90kg N ha'1 as compared to
other levels. Record variety did not respond to N application levels. The response of
sunflower to plant spacing and N application was not statistically significant. However.
high values for oil concentration, oil yield and seed yield was recorded at high plant
population (60 x 30cm) when fertilizer was applied either at 30. 60 or 90kg N ha'1.
respectively. Correlation analysis revealed that seed yield and total oil yield was
positively and significantly correlated with number of seeds head'1, percentage oil
concentration and seed weight head'1. Also oil concentration was significant and
negatively correlated with head diameter and seed weight head'1.
It is therefore
concluded from this study that hybrid variety (CRN 1435) is superior to Record (OP) in
terms of seed yield, oil concentration and total oil yield (kg ha'1). Narrow plant spacing
has greater influence on oil concentration and oil yield than on seed yield. The N
application levels were found to have similar effects for the parameters recorded except
at 0kg N ha'1.
Description
Dissertation
Keywords
Nitrogen fertilization, Plant population, Semi-arid conditions, Central Tanzania