Effect of osmopriming and irrigation regime on yield quantity and essential oil content of Cumin (Cuminum ciminum L.)

In order to investigate seed pre-treatment and irrigation interval effects on quantity and quality yield of the primed seeds of cumin (Cuminum ciminum L.), an experiment was carried out in research field of Vali-e-Asr University of Rafsanjan in 2009. The study was conducted as a Factorial experiment based on RCBD with four levels of seed pre-treatment (Control or without pre-treatment, seed pre-treatment with distilled water, seed pre-treatment with -0.3 and -0.9 Mpa PEG solution) and different irrigation intervals (5, 7, 9 and 11 days). The results indicated that the seed yield was significantly decreased with increasing of irrigation intervals which was related to more decrease of umbel number and seed number per umbel. The results also indicated that the percentage of the essence was increased with increasing irrigation interval however it was decreased in 11-day irrigation interval. Thousand seed weight and harvest index were not affected by seed pre-treatment and irrigation intervals. The highest umbel number in plant (14.62) and seed number per umbel (13.16) were obtained in seed pre-treatment of -0.3 Mpa PEG (P3), and in 5 and 7-day irrigation intervals. Totally, the highest seed yield (628.7 kg.ha-1) was obtained in seed pre-treatment of -0.3 Mpa PEG (P3) and 5-day irrigation interval and the highest essence content (3.62 %) was obtained in pre-treatment of distilled water (P2) and 7-day irrigation interval.