Yield improvement in black soil virginia tobacco (Nicotiana tabbacum L.)

The rate of improvement in leaf yields of TSS tobacco (Nicotlana tabbacum L.) varieties grown in India since 1947 and basis of yield improvements was studied. The estimated rate of gain in yield from 1953–98 is 178, 26, 20 and 24 kg/ha in green, cured and bright leaf and grade index, respectively. The rate of genetic gain from Chatham (1950) to VT1158 (1993) is 67, 12, 5 and 9 kg/ha in green, cured and bright leaf yields and grade index, respectively. The rate of gain due to production technology is 111, 14, 15 and 15 kg/ha in green, cured and bright leaf and grade index, respectively. Higher yields could be achieved mainly through development of light to medium cast varieties with late flowering and improvement in various morphological characters. Improvement in leaf number, leaf area and specific leaf weight and fine-tuning of leaf cast nature and flowering are essential for future yield gains.