Effects of Sowing Date and Planting Density on some of the Agronomic Traits and Di-allyl disulfide oxide (Allicine) Content of Garlic (Allium sativum L.)

Garlic (Allium sativum L.) is one of the most important plants in Hamadan province. Hamadan province with more than 2000 ha of garlic growing areas ranks first in Iran about 62 percent of garlic of Iran is produced in agronomical farms of this province.
In order to evaluate the effects of sowing date and planting density on some of the agronomic traits and Di-allyl disulfide oxide (Allicine) content of Garlic, (Allium sativum L.), an experiment was conducted in the growing seasons of successive years of 2012- 2013 at the agronomical farms of Hamadan. In this research used from garlic as a medicinal herbaceous plant and the treat ments were various of sowing dates and different of planting density. The experiment performed as split plot layout based on a complete randomized block design with four replications. The main factor was the sowing date with three levels (7 th october -22 th october- 6 th november) and sub factor was plant density with three levels (40000, 80000 and 120000 plants / ha). The agronomic traits that studyed in this research were consist of: bulb diameter, bulb let weight, bulb let length, bulb let diameter, and Di-allyl disulfide oxide (Allicine) Content, and seeds of garlic provided from Hamadan natural resources and agricultural research center. Di-allyl disulfide oxide amount was measured by Gas Chromatography (GC).
The results showed that various of sowing date and different of planting density had significant effects on bulb diameter, a clove weight, clove length and diameter and percentage of Allicine. The interaction effects of different of sowing date and various of planting density had significant difference on percentage of Allicine, but no significant effect on other characters was seen. The highest bulb diameter and clove length was obtained from sowing date of 7th October and 120000 plants per hectare and the highest of clove weight and diameter were obtained from the combination of 7th October and 40000 plants per hectare. The results showed that maximum amount of Di-allyl disulfide oxide was obtained from the combination of 6 th November and 40000 plants / ha.
Based on the result of this experiment, the sowing date of 6 th November and planting density 40000 plants in hectare is suitable to achieve ment to the highest and the best of produce and final yield and Di-allyl disulfide oxide (Allicine) Content of garlic as a medicinal herbaceous plant in Hamadan province.