Haphazard and inappropriate plant spacing and poor soil fertility management practices are among the major factors constraining onion production in the Central Zone of Tigray. Therefore, a field experiment was conducted in Axum district from October to March 2014 to assess the influence of intra-row spacing (2.5, 5, 7.5, 10 and 12.5 cm) and nitrogen rate (0, 41, 82 and 123 kg N ha-1) on growth, bulb yield, and quality of onion. The experiment was laid out in a randomized complete block design (RCBD) of factorial arrangement with three replications. The main effects of nitrogen rate and intra-row spacing influenced only the plant height and stand count significantly (P < 0.01). The tallest plants (46.70 cm) were obtained from plants treated with 82 kg N ha-1 as well as those spaced at 7.5 cm intra-row spacing (43.78 cm). The highest stand count (90.33%) at harvest was recorded from plots that received 82 kg N ha-1 and spaced at 12.5 cm (98.04%). Nitrogen rate and intra-row spacing interacted to significantly (P < 0.01) to influence all parameters. Thus, increasing the rate of nitrogen across the increasing intra-row spacing significantly prolonged days to maturity, enhanced average bulb weight, bulb diameter, bulb neck diameter, leaf number per plant, leaf diameter, shoot dry matter, and dry total biomass yield. In general, the highest values of these parameters (126.67, 123.85 g, 6.05 cm, 1.35 cm, 12.57, 1.38 cm, 3.22 g and 13.08 g, respectively) were attained in response to the application of 123 kg N ha-1 and 12.5 cm intra-row spacing. However, their least values (100, 23.99 g, 2.33 cm, 0.68 g, 6.60, 0.47 cm, 0.73 g, and 2.72 g, respectively) were obtained at 0 kg N ha-1 and 2.5 cm intra-row spacing. The highest value of bolting (31.95%) was observed from the application of 0 kg N ha-1 and plant spacing of 2.5 cm. Increasing the N rate across the increasing intra-row spacing increased the yields of over-sized bulbs whereas decreasing the yields of small-sized, under-sized bulbs and unmarketable bulb yield. The highest yield of over-sized bulbs (4.03 t ha-1) was recorded at 123 kg N ha-1 and the intra-row spacing of 12.5 cm.
Table of Contents
1. INTRODUCTION
2. LITERATURE REVIEW
2.1. Description of Onion Crop
2.2. Environmental Requirements of Onion
2.3. Importance and Production Status of Onion in Ethiopia
2.4. Response of Onion to Nitrogen Application
2.4.1. Roles of nitrogen in onion nutrition and growth
2.4.2. Response of onion to nitrogen fertilization
2.5. Effect of Plant Spacing on Onion Yield and Yield Components
2.6. Response of Onion to Interaction Effect of Nitrogen and Plant Spacing
3. MATERIALS AND METHODS
3.1. Description of the Study Area
3.2. Experimental Materials
3.2.1. Planting material
3.2.2. Fertilizer material
3.3. Treatments and Experimental Design
3.4. Management of Experimental Field
3.5. Soil Sampling and Analysis
3.6. Data Collection
3.6.1. Phenology and growth parameters
3.6.2. Yield and yield components
3.7. Data Analysis
4. RESULTS AND DISCUSSION
4.1. Physico-Chemical Properties of the Experimental soil
4.2. Phenology and Growth Characters
4.2.1. Plant height
4.2.2. Leaf number per plant
4.2.3. Leaf length
4.2.4. Leaf diameter
4.2.5. Shoot dry matter yield
4.2.6. Dry total biomass yield
4.2.7. Days to maturity
4.2.8. Bolting percentage
4.2.9. Stand count percentage
4.3. Yield and Yield Related Traits
4.3.1. Average bulb weight
4.3.2. Bulb diameter
4.3.3. Bulb neck diameter
4.3.4. Bulb dry matter yield
4.3.5. Total bulb yield
4.3.6. Unmarketable bulb yield
4.3.7. Marketable bulb yield
4.3.8. Under size bulb yield (< 20 g)
4.4. Harvest Index
4.5. Total Soluble Solid
4.6. Correlation Analysis
4.7. Partial Budget Analysis
5. SUMMARY AND CONCLUSION
6. REFERENCES
7. APPENDICES
Research Objectives
This study aims to optimize onion productivity in the Central Zone of Tigray, Ethiopia, by assessing the influence of intra-row spacing and nitrogen fertilizer application on onion growth, yield, and quality to develop specific regional agronomic recommendations.
- Effects of various intra-row spacings on onion plant growth parameters.
- Impact of different nitrogen fertilizer application rates on bulb yield and quality.
- Interaction between plant spacing and nitrogen levels on crop performance.
- Economic feasibility analysis of different treatment combinations via partial budget analysis.
Excerpt from the Book
4.2.1. Plant height
Result from the analysis of variance revealed that the main effects of nitrogen and intra-row spacing significantly (P < 0.01) influenced plant height of onion. However, the two factors did not interact to influence plant height (Appendix Table 1).
Increasing the intra-row spacing from 2.5 to 5.0 cm increased plant height significantly. Increasing the plant spacing further from 5.0 to 7.5 cm also increased the height of onion plants significantly whereas; the increase in plant spacing further from 7.5 cm to 12.5 cm did not show significant difference. Thus, the heights of onion plants grown at the spacing of 7.5 cm exceeded the heights of onion plants grown at the spacing of 2.5 and 5.0 cm by about 7% and 15%, respectively. Similarly, increasing the rate of nitrogen from nil to 41 kg N ha-1 significantly increased the height of onion. Increasing the rate of nitrogen further from 41 to 82 kg ha-1 also increased the height of onion plants. But, the mean height of plant did not show significant difference as further increase in nitrogen rate from 82 to 123 kg ha-1. Thus, the mean height of onion treated with nitrogen at the rate of 82 kg ha-1 exceeded the height of onion plants treated with nil and 41 kg N ha-1 by about 28 and 16%, respectively.
Summary of Chapters
1. INTRODUCTION: Outlines the importance of onion as a commercial vegetable crop, its global production context, and the specific agronomic challenges faced by smallholder farmers in the Central Zone of Tigray.
2. LITERATURE REVIEW: Examines botanical descriptions, environmental needs, nitrogen nutrition requirements, and the impact of plant density on onion growth, yield, and quality metrics.
3. MATERIALS AND METHODS: Describes the field experiment setup, treatments (intra-row spacing and nitrogen levels), experimental design, and the data collection methods used during the 2014 cropping season.
4. RESULTS AND DISCUSSION: Details the findings on soil properties, plant phenology, yield components, and economic performance, analyzing how different treatment combinations impacted bulb quality and harvest parameters.
5. SUMMARY AND CONCLUSION: Summarizes key experimental results, concluding that specific nitrogen rates and intra-row spacing significantly boost yield and profitability, offering recommendations for local production.
Keywords
Onion, intra-row spacing, nitrogen, marketable yield, bulb size distributions, growth parameters, agricultural productivity, Tigray, crop management, agronomic research, plant density, fertilizer efficiency, partial budget analysis, bulb quality, vegetable production.
Frequently Asked Questions
What is the core focus of this research?
The research investigates how varying intra-row plant spacing and nitrogen fertilizer levels affect the growth, yield, and overall quality of onion crops in the Central Zone of Tigray, Ethiopia.
What are the primary factors being studied?
The study examines intra-row spacing (2.5, 5, 7.5, 10, and 12.5 cm) and nitrogen application rates (0, 41, 82, and 123 kg N ha-1).
What is the ultimate goal of the research?
The objective is to identify an optimal combination of plant spacing and nitrogen fertilization that improves crop yield and profitability for farmers in the specific study region.
Which scientific methodology was employed?
The research utilized a randomized complete block design (RCBD) with factorial arrangements and three replications, followed by an analysis of variance (ANOVA) and partial budget analysis.
What does the main body of the work cover?
The main body focuses on growth characteristics, phenology, yield and yield-related traits (such as bulb weight and size), and the economic viability of the tested agricultural practices.
Which keywords define this work?
Key terms include onion, intra-row spacing, nitrogen, marketable yield, bulb size distributions, and agronomic management.
Did spacing affect bolting percentage?
Yes, the study found that bolting percentage significantly decreased with increasing nitrogen rates and wider intra-row spacing, likely due to reduced plant competition and enhanced vegetative growth.
What were the economic findings for local farmers?
The analysis identified that the application of 82 kg N ha-1 with a 10 cm intra-row spacing provided the most economically attractive balance of low production costs and high net benefits for smallholder farmers.
How does nitrogen level influence total soluble solids?
Nitrogen fertilization significantly increased total soluble solids, although this parameter decreased across wider intra-row spacings.
What is the recommendation for larger commercial investors?
For investors with full resources, using 82 kg N ha-1 with 5.0 cm intra-row spacing is recommended as a secondary option, as it produces the highest net benefit, albeit at higher production costs.
- Arbeit zitieren
- Guesh Tekle (Autor:in), 2018, Growth, Yield, and Quality of Onion (Allium cepa L.) as Influenced by Intra-Row Spacing and Nitrogen Fertilizer Levels in Central Zone of Tigray, Northern Ethiopia, München, GRIN Verlag, https://www.grin.com/document/454821
