Assimilate Partitioning in Relation to Crop Productivity

Abstract Assimilate partitioning may contribute to improvements in crop productivity by: a) Increasing total biomass production. Watson (99) drew attention to the subsequently well-qualified observation that assimilate partitioning patterns that favor rapid generation of leaf surface contribute significantly to both genetic- and environmentally induced differences in crop growth rates (87). b) Favoring assimilate transfer to the harvestable portion of the crop. Retrospective physiological analyses have demonstrated that shifts in assimilate partitioning pattern largely account for the evolutionary increase in yield of a range of crop species (for reviews, see ref. 37). Clearly, upper limits exist to the degree to which assimilates may be partitioned to the harvestable portion without jeopardizing the capacity of the plant to support the yield component both structurally and nutritionally. Nevertheless, in these cases, further potential exists for improvement through optimization of yield quality, which, in part, depends on the chemical nature of the assimilate partitioned to the harvested organ.