Studies concerning the release of new oriental tobacco genotypes, with superior characteristics of taste and aroma
For Oriental tobacco, quality is the most important feature and thus the main objective of breeding. Being more difficult than yield to determine, quality must take into account the taste, aroma, a high content of carbohydrates and low content of nicotine and albumin's. Romanian Oriental tobacco has a low content of nicotine (0.3 - 1.0%). Tobacco quality is positively correlated with precocity and resistance to drought and is negatively correlated with yield and resistance to diseases. The chemical analysis of the foliar surface is the only way to obtain an objective picture of quality, but it is also incomplete, coming only to complete the physical and testing methods of appreciation of the quality of the Oriental tobacco. Yield, as a main objective of breeding of Oriental tobacco, can be generally obtained by the individual selection of the most valuable plants. For Oriental tobacco, yield can be achieved only by choosing plants with large number of leaves, with dimensions typical for this tobacco and with proper aroma, short internodes and an oblique - vertical position of the leaves. The climatic conditions also have a special influence upon Oriental tobacco quality. This can be summarized by the ratio between the sum of temperature grades during the vegetation period and the amount of rainfall occurring in this period. Thus, the best Oriental tobaccos (small, thin leaves with low nicotine and albumin content and a high content of carbohydrates) are obtained in the areas where this ratio has high values. Having in view the numerous aspects raised by the areas grown with Oriental tobacco (clime, soil, amount of rainfall, rotation etc.), a strict zonation of the Oriental tobacco cultivars (subtypes Djebel and Molovata) is imposed so that a guarantee exists for constant and qualitative yields. Taking into account these aspects and also others that influence the quality of the Oriental tobacco obtained in Romania, the authors have produced a mathematical modelling of the qualitative elements of the Oriental tobacco. This program has in view the morphological, physiological and phonological characteristics of the Oriental tobacco cultivars, the soil, climatic and ecological characteristics of the areas where Oriental tobacco is grown, the best technological links (from sowing to curing and fermentation), the physical, chemical and smoking characteristics of the cured leaf as well as the resistance to diseases, pests, cold, drought, wind etc. From the interaction of all qualitative aspects of Oriental tobacco with those of growing conditions, the quantification coefficients and zonal distributions are obtained, and on this basis the decision is made as to which cultivars are to be grown, the best technological links to be used and also the brands of cigarettes into which the tobacco will be processed.