ABSTRACT
Cumin has been regarded as a temperate plant (12, 23). This species is successfully grown in the Middle East, North Africa and in parts of Asia and Europe, and its growing period completes before severe hot temperatures of late spring and early summer (8, 16, 18, 26). Optimum growth temperature of cumin ranges between 9° and 26°C, which usually coincides with late winter and early spring in many cumin growing areas. Therefore, in cumin producing countries such as Iran and India, this species is grown as a winter crop (22). Favorable environmental conditions for cumin production prevail in many parts of Iran. However, high relative humidity in the Northern parts of the country is the main growth limiting factor due to sensitivity of cumin to fungal pathogens such as Fusarium oxysporum, F. cerumini, Altemaria bumsii and Erysiphe polygoni which can easily spread at high levels of relative humidity (7, 13, 15). Therefore, cumin growing areas of Iran are restricted to dry regions adjacent to Central Desert (e.g. Khorasan, Isfahan and Kerman provinces). In India also relatively dry state, Rajasthan is the main state of cumin
production, more than 90% of the area under cultivation and production of cumin is allocated in this state. Districts such as Barmer, Jalore, Nagaur, Pali, Jodhpur, and Ajmer have the highest area under the cultivation of cumin.
