Growth and Dry Matter Accumulation Dynamics of Flue-Cured Tobacco under Different Soil Moisture Regimes

摘要

A filed research was carried out in the years of 2000, 2001 and 2003 in order to determine the effect of different irrigation regimes and water stress imposed at earlier growth stages on vegetative growth and dry matter accumulation of flue-cured tobacco plant (Nicotiana tabacum L.). The field trials were conducted on the fields of Ataturk Soil and Water Resources Research Institute in Kirklareli. A randomised complete block design with three replications was applied and K-326 Virginia tobacco cultivar was used in the experiment. Three levels of irrigation water amount reduction (0,40 and 60%) were applied at each development stage. Single irrigation was applied during the second part of vegetative stage, while subsequent water applications were done at 50 and 70% depletion level during the yield formation and ripening stages, respectively. Results of this 3-year study show that all vegetative parameters as well as dry matter accumulation processes were significantly affected by water shortage in the soil profile during the earlier growth stages. Water stress in various severity occurring during the rapid vegetative growth and yield formation periods reduced plant height, as well as influenced leaf number and leaf area development. Short-durationwater deficits during the rapid vegetative growth period caused 26,7 and 10; 10, 8 and 9 and 11.3, 8.5 and 9% loss of final dry matter weight of the plants, respectively for the three stress levels in 2000,2001 and 2003. Losses in the ranges of 40-70,15-17 and 22-25% could be expected as a result of water stress at three different levels during the yield formation period. Much greater 71, 82 and 71% losses were recorded as result of prolonged water stress during the periods of rapid growth and yield formation.