Nutrient Concentration Changes in Oriental Kabakulak Tobacco during the Growing Season

A three-year field study with Oriental Kabakulak (Nicotiana tabacum L. cv. Kabakulak-S2) was conducted on a sandy clay loam soil at Drama, Greece, to determine nutrient concentration patterns in tobacco plants. All cultural practices were those in use for commercial production of Oriental neutral type tobacco. Whole tobacco plants were sampled at weekly intervals from transplanting to the end of the harvesting season and separated into leaves, stalks and roots. The samples were washed, dried, weighed, ground, and analysed for nitrogen, phosphorus, potassium, calcium and magnesium. Nitrogen and potassium concentrations in leaves, stalks and roots tended to decrease during the 1st week after transplanting, then increased up to the 3rd or 4th week and declined thereafter. Phosphorus concentration in all plant parts decreased with time after transplanting. This decrease was greater during the first two weeks than later on. Calcium concentration in leaves and stalks increased from the first to the 2nd or 3rd week, then declined slowly up to the 8th week and remained constant thereafter. In roots, calcium decreased from the 1st to the 8th week and then remained constant. Magnesium concentration in leaves increased from the 1st to the 4th week and then remained constant. In stalks, magnesium increased from transplanting to the 2nd week and then declined slightly, whereas in roots magnesium decreased after the 1st week. Concentrations of nitrogen, potassium and calcium in leaves were similar and much higher than those of magnesium and phosphorus.