East African highland bananas (Musa spp., AAA-EAHB) are a distinct group of bananas growing in the Great Lakes Region where they are an important staple starch food and cash crop. Current yields are low in comparison with estimated potential yields and are declining. Several factors, such as drought, nutrient stress and pests and diseases have been reported to limit banana growth. Potassium has been identified to be the most limiting nutrient in banana production.
In order to quantitatively understand the effects of potassium nutrition on growth of East African highland banana, the model LINTUL BANANA 1, which models potential banana growth, was described and analysed, a literature study was executed and the obtained information was integrated by extending LINTUL BANANA 1 with the effects of potassium nutrition. Potassium nutrition affects the parameters light use efficiency, relative growth and death rate of leaves, and the partitioning of dry matter. Potassium concentration in the tissue water is a better indicator of potassium nutrition than potassium concentration on a dry weight basis. It was therefore proposed to extend LINTUL BANANA 1 by replacing the parameters affected with relations describing how the parameters depend on potassium concentration in the tissue water. For three parameters, hypothetical relationships have been proposed. Furthermore, it was hypothesized that these relationships can be explained by distinguishing between vacuolar and cytosolic potassium concentrations.
The modelling had helped organizing the available information. It was concluded that (i) LINTUL BANANA 1 can be extended with the effects of potassium nutrition by replacing parameters with relationships describing how these parameters depend on potassium nutrition and (ii) for a full quantitative understanding, these relationships have to be explained, not only described. The proposed hypotheses are relevant in different ways and lead to two different approaches in further research and modelling.