| dc.description.abstract | Highland bananas are an important staple food in East Africa, but their physiological growth pattern is influenced by drought stress and potassium (K) in Uganda. Modelling is a promising approach for evaluating crop response to applied inputs in generating management interventions. Dry matter content and partitioning to different biomass parts (corms, pseudostem and leaves) are important inputs in a banana growth model LINTUL-BANANA II. However, it is not known if application of potassium alters these model parameters. This information is important for including potassium module to LINTUL-BANANA II for it to simulate potassium-limited growth and allow for illuminating pathways to input management. A total of 45 plants at different phenological stages (small, intermediate and big) were destructively sampled from an on-going K response. The trial was set up with treatments of 0, 75, 150, 250 and 600 kg K ha-1 yr-1 applied in randomized complete block design at Kawanda, central Uganda. Samples of the different biomass parts (corms, pseudostem and leaves) were taken for determination of dry matter content and dry weight of each biomass part as well as the total dry weight per plant. Data were subjected to ANOVA in unbalanced design with phenological stage as a confounding variable. Means were separated using the least significant difference at 95% confidence level. Even though there was an increasing trend in total dry weight and leaf dry weigh per plant, this was not significant. Application of 600 kg K ha-1 yr-1 significantly increased the pseudostem and corm dry weight. However, dry matter content was only significantly higher in pseudosmtem where 600 kg K ha-1 yr-1 was applied. There was no significant difference in dry matter content in the leaves and corms with application of K compared to where no K was applied. Treatment effects may have been masked by the small sample size and the dry conditions in which the sampled plants grew. Tentatively, it can be concluded that banana K nutrition does not affect the DM content in leaves and corms, and it increases that in pseudostems when K is applied at a high rate of 600 kg K ha-1 yr-1. It is recommended that dry matter content in a given biomass part can be input in LINTUL-BANANA as a constant, regardless of plant K nutrition status, except where high rates of K equal to or higher than 600 kg K ha-1 yr-1 are applied when pseudostem dry matter content should be increased in the model as a function of the K rate applied. It is also recommended that this study be repeated with a larger sample size using plants that grew in optimal conditions except for K supply. | en_US |
