RESPONSE OF FLUE-CURED TOBACCO CULTIVARS NC 71 AND NC 72 TO SEED PRIMING: II. INFLUENCE ON TRANSPLANT PRODUCTION UNDER VARIABLE FLOAT-SYSTEM ENVIRONMENTS

Abstract Experiments were conducted over two years to determine the effects of priming on the performance of flue-cured tobacco cultivars, NC 71 and NC 72, in a greenhouse float system. Primed and non-primed seeds from the same seed lot were used each year, but seed lots differed within cultivars across years. In all experiments, treatments were replicated four times and arranged as a two by two factorial (cultivar × priming) in a randomized complete block design. A modified index of synchrony (ISM) was determined from daily emergence counts as a measure of uniformity of seedling emergence. The days required to reach 90% emergence (D90) also was determined. Temperature and solar intensity were recorded at each location. In both years, a significant cultivar × priming interaction was observed for D90 and ISM. In 1999, D90 was similar for primed and non-primed NC 71 seeds, but priming reduced D90 by three days for NC 72. Priming increased the ISM of NC 72, but decreased the ISM of NC 71. In 2000, priming NC...