Interaction of nitrogen fertilizer rates and plant population on growth, phenology, yield, and nutritional composition of Solanum scabrum
| dc.contributor.advisor | van Jaarsveld, C.M. Mavengahama, S. and Ntuli, N.R. | |
| dc.contributor.author | Ndlovu, Sindi | |
| dc.date.accessioned | 2024-07-16T08:50:24Z | |
| dc.date.available | 2024-07-16T08:50:24Z | |
| dc.date.issued | 2023 | |
| dc.description | A Thesis submitted to the Faculty of Science, Agriculture and Engineering in fulfilment of the requirements for the Degree of Master of Science in the Department of Agriculture at the University of Zululand, South Africa [2023]. | |
| dc.description.abstract | Solanum scabrum is a nutritious African leafy vegetable scarcely known in South Africa but consumed in other African countries. Very little is known about the agronomic requirements of this crop, including optimum fertilizer rates and plant population. This study focused on the effect of N fertilizer application and plant population on the growth, phenology, yield, and nutritional composition of S. scabrum. A field experiment was conducted at the University of Zululand farm in which S. scabrum was grown under 0, 100, 200, 300, and 400 kg ha-1 N (as limestone ammonium nitrate) and 100 000, 160 000, 220 000, and 280 000 plants per hectare in a randomised complete block design with three replications. Five randomly selected plants from the inner rows of each plot were marked and used to take measurements of vegetative traits (on plant height, leaf chlorophyll content, leaf area, and the number of leaves and branches) 35 days after transplanting. Phenological development of reproductive traits was recorded as duration (days after transplanting) to 50% flowering, fruit formation, and fruit maturity, using plants from the border rows. Plants from inner rows were harvested to measure marketable and non-marketable yield in fresh and dry mass (g). Ten centimetre long shoot tips were harvested for marketable yield at 35 and 56 days after transplanting. However, the non-marketable yield was determined from all aboveground parts harvested at 5 cm above soil level at the termination date. The same shoot tips were analysed for their N, P, K, Ca, Mg, Na, Al, Zn, Mn, Cu, and Fe content. Plant height and leaf area generally increased, but leaf chlorophyll content and the number of branches and leaves were inconsistent with an increase in N application. The effect of population size on plant height, the number of branches and leaves, leaf area, and leaf chlorophyll content were inconsistent. Nitrogen application of 300 and 400 kg ha-1 N and a low plant population (100 000 plants ha-1) increased the days to 50% flowering. Generally, applying N resulted in higher values for all yield parameters measured in this study. Further, yield parameters were higher at the lowest plant population (100 000 plants ha-1). Nitrogen application did not affect N, K, and Ca content, but reduced P content of the shoots. Its effect on the shoot Mg content was variable. Application of N had an inconsistent effect on the shoots’ Na, Zn, Cu, and Fe content. However, it reduced and increased the shoots’ Al and Mn content, respectively. Variation in plant population did not affect the macronutrients, whereas the application of N had an inconsistent effect on some micronutrients. The application of 300 kg ha– 1 was the optimum range for N fertilizer application, and 100 000 plants ha-1 was the optimum plant population relative to shoot fresh mass. This indicates potential for improving the crop through N fertilization, thereby contributing to food security and balanced diets in rural households in South Africa. | |
| dc.identifier.uri | https://uzspace.unizulu.ac.za/handle/10530/2570 | |
| dc.language.iso | en | |
| dc.title | Interaction of nitrogen fertilizer rates and plant population on growth, phenology, yield, and nutritional composition of Solanum scabrum | |
| dc.title.alternative | nitrogen fertilizer rates and plant population on growth | |
| dc.type | Thesis |