Zlatev G., Velkov V., Gerova C., Iordanov V. Oriental tobacco irrigation.
Taken of Donev N., G. Zlatev, et al. The Tobacco in Bulgaria. Editorial Jristo G. Danov: 229-243, Bulgaria, 1974.
In the oriental tobacco, the optimum level of moisture in the soil is / 70 – / 65-70 / – 50 / % of field capacity for the first, second and third phase of the growing season crop, usually in this type of tobacco apply from 2 to 4 irrigation, with partial water irrigation requirement from 300 to 400 m3/ha and total water irrigation requirement from 700 to 1440 m3/ha. The investigation of the different irrigation regimes, it has been established that with an optimal irrigation regime is stabilized yields and improves the yield and quality of the harvest, leaves are obtained clearer, with good combustibility, low-nicotine and more sugar content. In the oriental tobacco the most critical water requirements corresponds to the phase of active crop growth, the highest evapotranspiration occurs between the first and second harvest coincides with greater leaf area of tobacco.
Conduced researches show that a greater number of irrigation, do not lead to an increase the yield; on the contrary can diminish the quality of tobacco. From research, and practice has been established that there is not need to irrigation 1-2 days before harvest, due to physiological changes that occur in the technical maturity of the leaves, which leads to a decrease in the quality of harvest drying.