Traditional farmers have recognized the harmful effects of saffron debris on fallowing crop for many centuries. Little information is available on allelopathics effects of saffron on crop rotation. This study was conducted to examine the allelopathic effects of deferent soil incorporated parts of saffron, on emergence and seedling growth on tomato and wheat on greenhouse condition. Two experiment were conducted. In experiment 1, deferent rate of saffron leaves and corms incorporated in soil and its allelopathic effects on emergence and seedling growth of tomato and wheat were examined. In experiment 2, the emergence and growth of tomato and wheat were tested on deferent age of saffron and compared with check soil. Leaves and corms incorporated in the soil inhibited the emergence and growth tomato and wheat. Significant reduction in emergence , shoot length and dry weight of shoot were observed as the plant residues in the soil were increased. The concentration-dependence response of the test plant to saffron suggests that this plant might contain allelochemical(s). Apparently, the allelophathics effect on seed emergence and seedling growth of tomato and wheat was stronger compareed to those the corms. The soil under saffron cultivation also inhibited seed emergence and seedling growth of test plants. Age of saffron plantation did not explain the effectiveness of saffron on tested plants. In general, tomato was more sensitive than wheat to saffron residues. In conclusion further works is necessary to specify and verify the allelochemicals produced by this useful plant.

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