Effect of Sowing Date on Yield and Essential Oil Content of Cumin Ecotypes in Kerman

Cumin (Cuminum cyminum L.) is known as most important cultivable medicinal plant in Iran. This research was aimed to study the effects of sowing date on yield and essential oil content of cumin ecotypes. The experiment was conducted as split plot arrangement in a compeletly randomized block design with three replications on growing season of 2011 2012 in Agricultural Research Station of Kerman University. Different sowing dates were 26th December, 10th January, 25th January, 9th February and 24th February, and different cumin ecotypes consisted of Semnan, Fars, Yazd, Golestan, Khorasan-Razavi, Khorasan-Shomali, Khorasan-Jonoubi, Esfahan and Kerman were used as main and sub plots, respectively. Different agronomic traits, yield and essential oil content were measured. Effects of different sowing dates were significant on all traits except for the number of seed per plant. Ecotypes showed significant variations for all studied traits. The interaction of sowing dates and different ecotypes was significant for all the traits except for 1000-seed weight. Change in rank interaction was observed for some of the traits, which represent different response of ecotypes to different sowing dates. Calculated GDD for each ecotype also demonstrated the different thermal requirements of them. Therefore due to the large variability in cumin germplasm, it is necessary to find the sowing date, for each ecotype, according to the environmental factors and the cultivation aim. The results revealed that based on cultivation aim, for getting the highest seed yield, sowing of Kerman ecotypes in February and for getting the highest essential oil percent, early sowing dates of Kerman and Semnane ecotypes, can be recommended for Kerman.