Plant density and bulb size trial was conducted at Ziway in order to identify the optimum agronomic management practices, which contribute to maximized seed production in onion crop both in terms of quantity and quality. The experiment was laid down in split plot design with three replications, keeping plant density as main plot factor and bulb size as sub plot factor. The effects were studied by collecting data on bulb sprouting and plant performance, yield components, seed yield and seed quality parameters. Analyses of variance, mean comparison using least significant difference, correlation analysis were made using SAS computer software. Plant density significantly influenced bulb sprouting, umbel size, seed yield per 100m2and germination percentage. The largest umbel size (4.9cm) was obtained from low plant density; where as the smallest (4.4cm) from high plant density. Maximum seed yield per 100m2(1,163,446 seeds) was collected from high density while low density yielded only 416,240 seeds per 100m2. However the quality of seed in terms of germination was highest for seeds obtained from low density. The influence of bulb size was significant on plant height, number of flower stalks per plant, number seeded florets per umbel, seed per plant, seed per 100m2, seed yield (qt/ha) thousand seed weight. Plants grown from large bulbs produced plants with best height (72.3cm), highest number of flower stalks (8.5), seeded florets per umbel (368.7), seed per plant (1,539), seeds per 100m2(994,434) and seed yield in qt/ha (10.42). Seeds with best thousand seed weight (4.2g) were obtained from medium bulbs and small bulbs performed least in all aspects. Correlation analysis was made to study the relationship among plant growth, yield component, seed yield and quality parameters and their respective influence on yield and yield quality. Positive correlation existed between plant height and umbel size with seeded florets per umbel; flower stalk per plant, plant height, umbel size, seeded florets per umbel and number of seeds per floret with seed yield per plant, which was highly correlated with seed yield (qt/ha). However, further studies ought to be conducted in order to understand clearly, why bulb size and plant density interaction effect was insignificant
Key words: Plant density, bulb size, bulb sprouting, plant performance, seed yield and seed quality
Table of Contents
1 INTRODUCTION
2 LITERATURE REVIEW
2.1 Onion Crop Production
2.1.1 Onion Cultivars
2.1.2 Climatic Requirement
2.1.3 Soil and Fertilization Requirement
2.1.4 Water Requirement
2.1.5 Planting Date
2.2 Onion Seed production
2.2.1 Bulb-to-Seed Method
2.2.2 Seed-to-Seed Method
2.3 The Effect of Bulb Size and Plant density
2.3.1 Effect of Bulb Size
2.3.2 The Effect of Plant Density
2.4 Onion Flowering
2.5 Pollination in Onion Flowers
2.6 Onion Seed Setting and Maturation
2.7 Harvesting, Threshing and Seed Cleaning
2.8 Onion Seed Quality
2.9 Biotic Limiting Stresses
3 MATERIALS AND METHODS
3.1 Research Site Description
3.2 Experimental Treatments and Design
3.3 Management practices
3.4 Data Collection
3.5 Data Analysis
4 RESULTS AND DISCUSSION
4.1 Effect of Bulb Size and plant density on Bulb Sprouting and Plant Growth
4.1.1 Bulb Sprouting and Plant Stand
4.1.2 Plant Height
4.1.3 Umbel Size
4.2 Effects of Bulb Size and Plant Density on Seed Yield Components
4.2.1 Number of Flower Stalk per Plant
4.2.2 Number of Seeded Florets per Umbel
4.2.3 Seeds per Floret
4.3 Effects of Bulb Size and Plant Density on Seed Yield
4.3.1 Number of Seeds per Plant
4.3.2 Number of Seeds per 100m2
4.3.3 Seed Yield (qt per ha)
4.4 The effect of Bulb Size and Plant Density on seed quality
4.4.1 Thousand Seed Weight
4.4.2 Germination percentage
4.5 Correlation Analysis
5 SUMMARY AND CONCLUSIONS
Research Objectives and Themes
This study aims to determine the optimal agronomic management practices for maximizing onion seed production in terms of both quantity and quality. The research investigates the independent and combined effects of plant density and mother bulb size on growth, yield components, and seed quality parameters under conditions in Zway, Ethiopia.
- Effects of plant density on onion seed yield and quality.
- Influence of mother bulb size on seed production potential.
- Assessment of growth parameters and yield components.
- Correlation between growth, yield, and seed quality traits.
Excerpt from the Book
2.1 Onion Crop Production
Common onion constitutes the large bulk of economically important varieties. They all form a single bulb and are mostly grown from seed. When the plant is grown for production of green or bulb onions, it is treated as an annual, which rarely gets more than about 31cm tall. The seeds are planted in the field or started in protected areas then transplanted, when 10 to 12 cms tall, into the field. A few weeks later, when the top growth or the bulb has reached the proper size or condition, the entire plant is harvested and the desirable parts marketed. No seeds are produced and no pollination is involved.
In the springtime, the bulbs initiate normal growth, and then produce from 1 to 20 flower stalks, about 90cms tall. This is referred to as "bolting," an undesirable trait in green or bulb onion production but essential in seed production (www.oregonstate.edu). Bolting is strongly influenced by day length and temperature, and cultivars are bred to bolt at certain times in different areas. For this reason, northern and southern types are not interchangeable. Many cultivars have been developed for different regions and purposes northern and southern, purple and white bulbs, strong and mild-flavored (Robinowitch and Brewster, 1990).
Summary of Chapters
1 INTRODUCTION: Outlines the economic importance of onions as a global vegetable crop and identifies research gaps in optimizing seed production in Ethiopia.
2 LITERATURE REVIEW: Examines existing knowledge on onion production, cultivar classification, climatic requirements, seed production methods, and the impact of plant density and bulb size on seed yield.
3 MATERIALS AND METHODS: Describes the experimental site, layout (split-plot design), treatments, management practices, and data collection procedures used for the study.
4 RESULTS AND DISCUSSION: Analyzes the experimental data regarding the effects of bulb size and plant density on bulb sprouting, plant growth, yield components, seed yield, and seed quality, including correlation analyses.
5 SUMMARY AND CONCLUSIONS: Summarizes key findings and provides recommendations for optimal bulb size and planting density to enhance seed production.
Keywords
Plant density, bulb size, bulb sprouting, plant performance, seed yield, seed quality, Allium cepa, onion seed production, germination percentage, umbel size, flower stalk, vernalization, agronomic practices, crop management, Zway.
Frequently Asked Questions
What is the primary focus of this research?
The research focuses on identifying the optimal agronomic practices, specifically plant density and bulb size, to maximize the quantity and quality of onion seed production.
What are the central themes of the work?
The work explores how different planting strategies and mother bulb sizes influence bulb sprouting, plant height, flowering, seed yield components, and final seed quality.
What is the core research question?
The study asks how varying plant densities and mother bulb sizes affect the agronomic performance and seed yield potential of the onion crop in the Zway region.
Which scientific methods were employed?
The experiment utilized a split-plot design with three replications. Data were analyzed using SAS software, including analysis of variance (ANOVA), least significant difference (LSD) mean comparisons, and Pearson correlation analysis.
What does the main body cover?
The main body details the materials and methods used in the field experiment, followed by a comprehensive presentation and discussion of results concerning growth parameters, yield components, and seed quality metrics.
Which keywords characterize this study?
Key terms include plant density, bulb size, onion seed production, seed yield, seed quality, bulb sprouting, and Allium cepa.
How does plant density affect seed yield per 100m2?
The study found that high plant density (narrow spacing) resulted in the highest number of seeds per 100m2 due to a higher plant population, although it did not necessarily maximize seed yield per individual plant.
What impact does mother bulb size have on plant performance?
Larger mother bulbs were found to perform better in terms of plant height, number of flower stalks per plant, number of seeded florets per umbel, and overall seed yield per plant.
Why is the interaction effect between bulb size and plant density significant or insignificant?
The results indicated that the interaction effect was not statistically significant, suggesting that these two factors operated independently within the scope of this experiment.
What is the conclusion regarding seed quality?
The research concluded that while high planting density increases yield per area, it can have a negative influence on certain seed quality attributes, such as germination percentage and thousand seed weight.
- Arbeit zitieren
- Zerihun Zena (Autor:in), 2008, The Effect of Bulb Size and Plant Density on Yield and Quality of Onion (Allium cepa var cepa L) Seed, at Ziway, Central Ethiopia, München, GRIN Verlag, https://www.grin.com/document/208620
