Temporal Patterns of Sesame (Sesamum indicum L.) Nutrient Uptake in the Southeastern US.

Sesame (Sesamum indicum L.) is an alternative row crop that is well-adapted to climatic conditions in the southeastern US, but the temporal dynamics of sesame nutrient uptake have not been thoroughly investigated. This information is needed to better inform fertilization decisions and improve nutrient use efficiency. The objective of this study was to characterize nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S) uptake and partitioning by cultivars recommended for production in the region. A two-year field study was conducted in 2015 and 2016 in Jay, FL. Data from 2015 are presented. Cultivars (S34, S35, and S39) were sampled at different growth stages and divided into stem/branch, leaf, flower/capsule, and grain components to determine N, P, K, Ca, Mg, and S uptake and partitioning. Nutrient uptake was significantly affected by growth stage, but there was no cultivar or cultivar x growth stage effect. Cultivars accumulated nutrients most rapidly from late-vegetative through early-bloom stages during which time 11 kg N ha^-1 day^-1, 1.3 kg P ha^-1 day^-1, 13 kg K ha^-1 day^-1, 5.4 kg Ca ha^-1 day^-1, 1.5 kg Mg ha^-1 day^-1, and 0.9 kg S ha^-1 day^-1 were taken up. During this period, 57-65% of total nutrient uptake occurred. Harvested grain removed (per ha) approximately 56 kg N, 11 kg P, 11 kg K, 15 kg Ca, 6 Mg, and 5 kg S. These results suggest that plant available nutrients during late-vegetative and early-reproductive growth may improve nutrient use efficiency by sesame.