Abstract:
This study was carried out at the Demonstration Farm of pomology,
Department of Horticulture, College of Agricultural Studies, Sudan
University of Science and Technology during the summer and winter
seasons of the years 2006-2011. The objectives of the study were to identify
the response of annuals flowering ornamental plants to plant spacing and
nitrogen. Also the aim of the study was to assess the ability of annual
flowering ornamental plants to produce seeds under Sudan condition.
The Plants included in this study were 1/Summer annuals: celosia
(Celosia cristata) and zinnia (Zinnia elegans). 2/Winter annuals: snapdragon
(Antirrhinum majus) and carnation (Dianthus caryophyllus). The F1 seed for
mentioned plants were imported from Holland, Denmark, Japan and Egypt.
Two experiments were carried out for each plant species. The
experimental design was complete randomized block design. Computer
program has been used for data analysis and Duncan multiple range test was
used for comparison between the means. Experiment one: nitrogen (as urea)
at level of 0, 25 and 50 kgN/fed fifteen days after transplanting of seedlings.
Experiment two: Manure added at the rate of 0, 150 and 300 kgN/fed during
land preparation. The plants were spaced at 20, 30 and 40cm. Data recorded
and evaluated include vegetative growth (plant height, number of
branches/plant and number of leaves/plant), flowers yield and quality and
seeds yield and quality.
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The results revealed that, application of different sources of nitrogen
(urea or manure) promoted growth of both summer and winter annuals. It
gave the highest values of growth. Addition (50KgN) of urea or 300 kg/fed
manure gave the best vegetative growth of all tested plants in both seasons
compared to 25 kgN/fedof urea and 150Kgs manure. High doses of both
urea and manure delayed flowering in carnation and snapdragon. Moreover,
flowers yield and quality, seed yield and quality were affected positively by
addition of nitrogen.
The results showed that, increasing of plant spacing decreased plant
height but increased number of branches/plant in all tested plants in both
seasons. However, there were no significant effects on flower initiation of
celosia and snapdragon. However, closer spacing delayed flowering of
carnation. Maximum flowers yield and quality (number of flowers/plant or
inflorescences, flower diameter and flower age) of celosia, zinnia,
snapdragon, and carnation were recorded at spacing of 30 and 40cm.
Maximum number of seeds, germination rate and uniformity of snapdragon
were recorded at the wider spacing (40cm). Maximum number of seeds,
germination rate and uniformity of celosia and carnation were recorded at
closer spacing (20, 30cm).
