Evaluation of phytochemical properties of purple coneflower [Echinacea purpurea (L.) Moench] flowers in intercropping with green beans and different summer time planting dates

To evaluate dry matter yield and phytochemical properties of two years old purple coneflower [Echinacea purpurea (L.) Moench] flower in intercropping with green beans and different summer time planting dates, a randomized complete block design in split plot arrangement with three replications was conducted in Research Farm of Genetics and Agricultural Biotechnology Institute of Tabarestan in 2012-2013. Treatments included planting arrangements [coneflower and green bean monoculture, replacement intercropping planting with patterns of 1:1 and 2:2 ratio of coneflower: green beans], planting dates (June 30, July 30 and August 29), and cultivation of green beans in the spring of 2012 coincided with the emergence of coneflower.Results of the experiment showed that planting date of June 30 increased dry matter, caffeic acid derivates, total phenol and flavonoid contents of flower. Among the intercropping planting arrangements, patterns of 2:2 ratio of coneflower: green beans, increased flower dry matter. While the highest amount of cichoric acid, chlorogenic acid and echinacoside (29.3, 2.4 and 2.3 mg/g dry matter, respectively) were obtained in coneflower plants cultivated as sole crop. The maximum amount of total phenol and flavonoid contents of flower were detected in coneflower plants cultivated in June 30 and sole cropping pattern. Overall, it can be concluded that if the aim of cultivation of this plant is increasing production of caffeic acid derivatives, sole cropping is better than mixed cropping. However, for dry matter improvement, mixed cropping has more advantages. In addition, early cultivation of the crop is more suitable for caffeic acid derivatives and dry matter production than delayed planting.