Evaluating effects of top-dressing timing on two flue-cured Virginia tobacco (nicotiana tabacum l.) varieties lower cures quality
- Author
- Chimusaru, Elisha
- Title
- Evaluating effects of top-dressing timing on two flue-cured Virginia tobacco (nicotiana tabacum l.) varieties lower cures quality
- Abstract
- Optimal nitrogen management is crucial for enhancing the market-driven quality of lower flue-cured tobacco (Nicotiana tabacum L) leaves. This study evaluated four top-dressing timings: control (no N), 2g ammonium nitrate (AN) at planting, 8g AN at planting, and split application (5g at planting + 3g at topping) on growth, yield, and cured quality of Krk 26 and Krk 76 varieties. Field experiments measured leaf area (weeks 4, 6, 8), plant height, leaf dry weight, yield, and cured color. Split applications maximized leaf area development (p<0.001 at week 8), with Krk 76 exhibiting 35% greater expansion than Krk 26 under this regime. While all nitrogen treatments increased plant height (p<0.001) and yield (p<0.001) over control, split applications achieved peak yield (393,333 kg/ha in Krk 76). Cured color depended solely on nitrogen sufficiency (p<0.001), with both 8g basal and split treatments scoring optimally. Results demonstrate that split nitrogen applications synchronize with critical growth phases to maximize leaf expansion and yield, particularly in high-vigor varieties like Krk 76, while maintaining cured quality requires minimum nitrogen thresholds (≥8g AN equivalent). Growers should adopt variety-specific split timing for Krk 26 and ensure adequate total nitrogen for Krk 76 to optimize lower-cure outcomes.
- Date
- June 2025
- Publisher
- BUSE
- Keywords
- Split-application synchronization
- Varietal nitrogen responsiveness
- Sink strength divergence
- Supervisor
- Mr. Mutsengi
- Item sets
- Department of Crop Sciences
