1 main shoot growth stage leaf production stage SGN:0000012 MaizeGDB:1863 This stage is recommended over rosette growth or stem elongation as it is most easily observed and least ambiguous. PO:0007133 The stage at which the leaves produced by SAM are visible above the ground in a seedling or mature plant. 1 seedling (related) leaf production in Solanaceae (related) plant_structure_development_stage