Physiological and yield responses of cassava (manihot esculent crantz) to fertilizer and leaf harvesting treatments under different cropping systems in Luapula province of Zambia.
| dc.contributor.author | Mwamba, Sydney | |
| dc.date.accessioned | 2024-09-25T08:57:12Z | |
| dc.date.available | 2024-09-25T08:57:12Z | |
| dc.date.issued | 2023 | |
| dc.description | Thesis of Doctor of Philosophy in Agronomy. | |
| dc.description.abstract | Comparatively, Zambian smallholder cassava productivity is low. Zambian farmers produce 6 ton ha-1 , compared to 20–25 ton ha-1 in Zambia. Therefore, understanding smallholder farmers' poor yields is necessary to develop cassava cropping systems for yield intensification. In this study, field trials were conducted to evaluate the performance of three cassava varieties for yield, physiology, and morphology under four fertilization regimes while three varieties were assessed for field performance under NPK fertilizer and no fertilizer (Control). In addition, three cassava varieties were evaluated for growth, yield, and radiation use efficiency (RUE) in response to three leaf harvesting intensities and two fertilizer management regimes. The trials were conducted for two seasons at the Zambia Agricultural Research Institute Station (ZARI) in the Mansa District of Luapula Province. For objective (i), Fertilization regimes were treated as the main plot, Mweru (V1), Bangweulu (V2), and Katobamputa (local) (V3) were subplots while for objective (ii), the same cassava varieties were used, either with NPK fertilization and no fertilizer treatment. Objective (iii)examined three cassava varieties (Bangweulu-V1, Mweru-V2, and Katobamputa-V3) under two fertilizer management regimes (M1=Control and M2 NPK+Lime) and variable leaf harvesting intervals (D1 = no leaf harvesting, D2 = 2-week, and D3 = 3-week respectively) using split-split plot design. At 75–410 days after planting (DAP), leaf area index (LAI), light interception, yield, and yield components were measured at six different times, along with daily weather data. Using a linear mixed model, analysis of the variance examined fertilization regimes, variety, and harvesting interval effects using R-statistical software. Tukey's Honest Significant test was used for mean separation. Cross-treatment Pearson correlation was used to compare continuous variables for treatment means while stepwise regression was used to determine the most important cassava yield components. Irrespective of the variety, NPK + lime followed by NPK only yielded more and had a superior response for cassava yield components than lime and the control. NPK fertilisation increased cassava RUE, light extinction coefficient, and yield across seasons and varieties. Harvesting 5-8 young cassava leaves per plant at 3- week intervals for home and commercial use may not affect yield, independent of fertilizer or variety according to this study. Cassava growth, root yield, LAI, and RUE were affected by bi-weekly leaf harvesting. In poor soil nutrient conditions, NPK fertilizer+ lime, and NPK fertilizer treatments can increase cassava productivity, physiology, and morphology under high-rainfall environments. | |
| dc.identifier.uri | https://dspace.unza.zm/handle/123456789/8898 | |
| dc.language.iso | en | |
| dc.publisher | The University of Zambia | |
| dc.title | Physiological and yield responses of cassava (manihot esculent crantz) to fertilizer and leaf harvesting treatments under different cropping systems in Luapula province of Zambia. | |
| dc.type | Thesis |