Evaluation of phenotypic variability and agronomic trait performance of different jute mallow genotypes (corchorus species) from Northern, Western and Eastern Uganda

Abstract

Knowledge of morphological characterization and phenotypic trait variability are very important in selection of traits for improvement as well as discrimination of germplasm in improvement programmes. Three accessions of jute mallow (Corchorus species) were collected from Kasese in western Uganda, Soroti in Eastern Uganda and Gulu in Northern Uganda and were evaluated for morphological variability and phenotypic trait performance. The experiment was carried out in Makerere University Agricultural Research Institute Kabanyolo and the replications were set on raised blocks using Randomized Complete Block Design. Data was collected on growth and development parameters, yield parameters and incidence of pests and diseases Data collected were subjected to statistical analysis using R and RStudio interface and analysis of variance (ANOVA) was performed to test for differences between the genotypes, Fisher’s LSD at a 5% significant level to separate the means between the genotypes. The results revealed significant differences in days to germination whereby there was no germination in the accession from Soroti and northern accession germinated earlier than the western accession. There was significant difference in the days to 50% flowering between the northern (44 days) and western (56 days) at p<0.001. Significant differences were also observed in plant height between the western and northern accession in week 5 whereby northern was taller than western accession at p<0.05 and in week 9 where western accession was having higher mean height, 92.47 cm than northern, 82.90 cm at p<0.001. This led to prolonged vegetative time for western accession and there was significant difference in leaf number in that the northern accession had more leaves than the western accession and more branches before pod initiation after which the number of branches and leaves remained constant and others fell off and dried as the western accession with late flowering continued to put more branches and leaves. There was significant difference in leaf area between the western and northern accession at P<0.001 in that western accession had leaves with larger leaf area than northern throughout the plant growth cycle. However, leaves of western accession were heavily defoliated by pests unlike those of northern accession It was then recommended that corchorus accession from Kasese should be improved by breeders in order to come up with varieties with desirable horticultural traits since it was better performing with larger surface area leaves, more branches at later stage which increases its harvesting period as compared with northern accession