Sucrose functions as a transported sugar and carbon carrier between source and sink tissues in plants, influencing numerous growth processes and physiological events. To examine the effect of foliar‐applied sucrose on carbohydrate allocation and biomass distribution in different cauliflower organs, a factorial experiment was conducted using a completely randomized design (CRD) with four replications. The first factor was sucrose foliar application at two levels (0% and 1%), and the second factor was six plant growth stages: (1) 8–14 true leaves; (2) 14–20 true leaves; (3) more than 20 true leaves up to curd initiation; (4) curd formation stage; (5) curd diameter reaching 50% of the expected size; and (6) harvestable dense curd. Results showed that leaf carbohydrate concentration was initially low but gradually increased, peaking at stage 4. As the plant transitioned to the reproductive phase, carbohydrates were increasingly translocated to the curd, leading to a significant reduction in leaf carbohydrate content, particularly evident at stage 6 compared to stages 4 and 5. At stage 3, just before the reproductive phase, the leaf‐to‐plant weight ratio was highest. However, a sharp decline in this ratio was observed after curd initiation (stage 4), continuing through stage 5. At the harvest stage, analysis of fresh weight distribution among sucrose‐treated plants revealed that the curd accounted for the highest proportion (51.61% of total plant weight), followed by leaves (36.93%), stems (16.38%), and roots (5.18%). In contrast, control plants (no sucrose application) had the highest fresh weight in leaves (44.21%), followed by the curd (34.75%), stem (15.58%), and root (5.47%). These findings suggest that sucrose foliar application enhances carbohydrate translocation to the physiological sink (the curd), thereby modifying the source–sink relationship by regulating sugar partitioning and physiological processes. The onset of reproductive growth and the initiation of floret development appear to be critical stages when external carbohydrate supplementation—such as foliar‐applied sucrose—is most beneficial and can improve curd yield rather than other phenological stage.
Ghasemi et al. (Thu,) studied this question.