Bull. Spec. CORESTA Congress, Lisbon, 2000, p. 106, APOST5

Precocious Burley

Tobacco Research Center, Orumieh, Iran.
The West part of Iran is located between Turkey, Iraq and Zagros chains. These provinces are known as a mountainous, cold area with fairly short summers. For centuries tobacco farmers of this region have cultivated different oriental and other local sun-cured varieties. According to numerous studies and several experiments, there are some micro climates that are quite different from the nature of this region. In some parts the non-frost days exceed 180 days with an average temperature allowing the production of air-cured varieties in good conditions. Normally the cultivation of tobacco without irrigation is not possible in the west part of Iran, for this purpose they are using 7 up to 10 irrigations for one season. Recently with the starting of a new cigarette factory in north part of Iran (Rasht), the need for Burley tobacco has increased considerably, so the fertile, deep and well drained soils are going under cultivation of this type of tobaccos, particularly in Khoy, Marivan, Mahabad and Kermanshah.We can say that except for irrigation, there is no problem in the field, but the curing of the latest primings causes some troubles, and is very expensive. In 1995 we decided to produce a precocious air-cured variety to overcome this problem and reduce the curing costs by cultivating it during the warm days of summer. We used therefore Mutant no 4 which is a very precocious sun-cured semi-oriental tobacco. This variety is bred in Oroumieh and has been presented in a paper given at the 1996 CORESTA Congress. The seedlings of this variety only take 50 to 55 days and the field period usually takes less than 70 days. A successful reciprocal cross with Burley 21 was achieved in 1996.In 1999 more than 155 lines have been seeded, and 124 ones were transplanted in the fields. We investigated some genotypes among which we found 30 giant individuals offering more than 40 leaves. Genotype n°123.10 is the best with 48 leaves. These lines do not blossom, but most of them are quite precocious. The selected lines in seedbeds and fields have a life cycle shorter than relative parent, Burley 21. In this project it seems that 25 up to 30 days precocity can be expected. For year 2000 we have selected 330 lines that are already seeded in the seedbed.