Influence of Different Levels of Soil Moisture on Yield and Quality Characteristics of Coker (flue-cured) Tobacco

A field study was carried out from 2003 to 2004 in order to determine the effect of different soil moistureregimes and water stress imposed throughout vegetative growth stages of Coker 347 (flue-cured) tobacco plant(Nicotiana tabacum L.). A randomized block design with five treatments and three replications was applied at RashtTobacco Research Station in Guilan provience, Iran. Treatments were 40, 60, 80 and 100% of total available water(TAW) and non irrigated (dryland farming) as a control. At the end of flowering stage, some traits which were relatedto yield and also quality characteristics of tobacco plants were measured. The combined analysis of variance showedthat all the traits except number of leaves per plant, sugar percentage, and nicotine percentage were affected by TAW.The effect of year was significant on traits of yield components and quality treats due to the high precipitations in thesecond experimental year. Furthermore, the effect of year was no significant on the traits related to yield except forfresh leaf yield. However, the treatment of 40% of total available water (TAW1) was the best in fresh leaf yield, dry leafyield, unit price and gross income in unit area. The non irrigated treatment (TAW0) was the lowest in fresh leaf yield,dry leaf yield, unit price and gross income in unit area. In addition the values of nicotine percentage and sugar tonicotine ratio for all of the treatments were higher and lower than their common levels, respectively.