Yield of chamomile capitula and essential oil in competition with weeds in different spacings and sowing dates

Chamomile Is an Important socioeconomic option for family farming. Its cultivation Involves manual management practices and herbicide use restriction, and knowledge regarding weed interference on the yield of chamomile capitula and essential oil quality is still limited. In this perspective, this study aimed to assess the effect of sowing dates, plant spacings, and hoeing management on the yield of chamomile capitula, essential oil yield, and essential oil content under the environmental conditions of a region with a Humid Subtropical climate without defined seasons. The experiments were conducted on four dates (March 18, March 28, June 31, and August 30, 2017, with plants spaced 0.05, 0.10, 0.15, 0.20, 0.30, and 0.40 m within rows. On March 28 and May 14, 2018, the spacings between plants in the row were 0.05, 0.10, 0.15, and 0.20 m, including two hoeing managements (with and without weeds). The variables analyzed in the two years were the yield of dry capitula, the dry mass of chamomile plants and weeds (g m-2), and the content and yield of essential oil in 2018. The sowing dates influenced the yield of floral capitula, the essential oil content, and the essential oil yield as a function of the duration of the cycle and weed occurrence. The autumn sowings resulted in a higher yield of floral capitula in both years. A linear reduction trend was also verified in the yield of floral capitula with the increase in plant spacing within the row from 0.05 to 0.20 m in the two crop years.