Study on the Effects of Defoliation on the Growth of Cotton Plant Using the Functional Structural Model GREENLAB

For the functional structural plant model GREENLAB, parameters for the source and sink relationships can be retrieved through model inversion with plant architectural data as targets. In order to study more precisely the production of source organs, a controlled defoliation experiment was performed on single-stemmed cotton plants. Four regular leaf-pruning treatments were implemented to produce single-stemmed plants that retained a given number of functional leaves (i.e., 6, 9, 12 and 15, respectively) at the top of stem during the whole period of plant development, and compared with control plants (single-stemmed plants retaining all the leaves). Results show that the most productive treatment in terms of fresh above-ground biomass was the treatment with 12 functional leaves retained, which were significantly greater than control plants. The optimized functional parameters of GREENLAB for the source and sink relationships were found to be affected in relation with the number of functional leaves retained on the plants.