The experiment was carried out at the experimental field of the Institute of Tobacco Products – Markovo in 2008-2010. The randomized complete block design with 4 replications and 25 m2 plot size was used. The new burley large type tobacco hybrids (Staikov and Yankov, 2000) in F1 - X- 1534, X-1538, X-1553, X-1562 and X-1566 were investigated. The aim of the investigation was to estimate the new hybrids by yield and quality of cured tobacco using Burley 1317 as a control. The plants were grown in compliance with the standard technology. The statistic processing of the data was made according to АNOVA, DUNKAN – multiple-range test.The results showed that the cured tobacco yield was higher in the new hybrids in comparison with the control. The highest yields were obtained from hybrid X-1553, which exceeded the control Burley 1317 by 29.8 %. On analyzing the data ANOVA of cured tobacco yield it was ascertained that the variants had statistic influence on the yield - η 60, while the years with their specific climatic conditions exercised a non-significant influence on the values of that characteristic - η 2. In terms of quality of cured tobacco (I class – 31.6 %) and nicotine content (3.44 %) the X-1566 hybrid exceeded the studied variants. The highest total nitrogen content was established in the X-1538 hybrid (3.59 %). The sugar, ash and ammonia content in all studied variants were in optimal values.
Testing of new burley large-leaf type tobacco hybrids under the conditions of South Bulgaria