Evaluation of potassium application methods and rates on the yield and quality of flue-cured tobacco
With rising input costs, growing environmental concerns, and new higher yielding cultivars, potassium fertilizer recommendations must be accurate. Research is being conducted to evaluate the effects various potassium rates and application methods have on the yield and quality of flue-cured tobacco. Research was conducted at the Upper Coastal Plain and Oxford Tobacco Research Stations in 2009. One study evaluated the effects of nine potassium rates from 0 to 225 lbs/A, all applied at transplanting, on flue-cured tobacco. The second study evaluated the effects of four potassium rates; 75, 125, 175, 222 lbs/A, and four application timings; broadcast one month before planting, broadcast one week before planting, at planting, at planting and layby, on flue-cured tobacco. Potassium-magnesium sulfate was used to supply the potassium in both studies. Soil samples and tissue samples were collected throughout the season. Cured leaf yield and chemical and physical quality data were also collected. There was no significant difference between treatments and control plots. Lower rates of K-Mag were acceptable under these conditions, along with broadcast application.