General Commission for Scientific Agricultural Research ،Administration of Natural Resourses
Faculty of Agriculture,Damascus University,
The research was carried out at Abu-Jarash Farm, (Faculty of Agriculture – Damascus University ) during the season 2015–2016 to determine the water requirement of Black cumin (Nigella sativa L.). And then study the effect of water stress ( through the application of several levels of deficit irrigation ) in the productivity of Black cumin quantitative and qualitative to determine the crop response to drought conditions.
Four irrigation treatments (100%, – 80%, – 70%, – 60%) of full irrigation were applied in four replications by using full random sectors.
The Evapotransoiration crop and crop coefficient were calculated. Yield, water use efficiency, Crop response coefficient for deficit irrigation, oil ratio in seeds, and some indicators ( length of growth, date of flowering, height of plant, weight of 1000 seeds) were studied.
The Evapotransoiration crop was determined by 3947 m3/ h. The values of the crop coefficient were determined by stages of growth with the following values: (0.4, 0.62, 1.17, 0.77).
Deficit irrigation has decreased the studied indicators ( length of growth, date of flowering, height of plant, weight of 1000 seeds, oil ratio in seeds, productivity) with significant differences in the treatments 70 % and 60% compared to the complete irrigation treatment, and without significant differences in treatment 80% Compared to treatment 100%.
Treatment 80%of the full irrigation was superior with the highest value of water use efficiency (0.25 kg / m3) compared to other treatment, Without a significant reduction in productivity compared to the savings in water consumption. The treatment also recorded the best value ( 0.23 ) of the crop response coefficient for deficit irrigation, indicating that the plant is well tolerated in water stress conditions.
Keywords: water stress, productivity, Black cumin, water use efficiency, deficit irrigation.