Biological indicators of Bulgarian and introduced Burley tobacco varieties

The biological indicators of ten Bulgarian and introduced Burley tobacco varieties were analyzed. The analysis showed that the expression of the biological indicators is closely related to the genotype and is insignificantly influenced by the environmental conditions. The most favorable results for all morphological features and the length of the vegetation period was for the Burley 1344 variety, which can be used in the breeding programs as a donor to improve the biological parameters of Burleys tobacco. In the other studied varieties of Burley tobacco, there was uniformity in morphological parameters. Pliska 2002 variety was not suitable for the Burley tobacco standard, because it presents with a small leaf width in the middle harvesting belt and too long vegetation period for the Burleys tobacco varieties. Bulgarian varieties were more favorable biological indicators that those of the introduced varieties. From the introduced varieties with optimal biological parameters was characterized Burley 21 variety.