Effects of different levels of animal manure and bulb weights on yield and yield components of caraway (Bunium persicum Bioss.)

In order to study the effects of different levels of animal manure and bulb weights on growth criteria, yield components, seed yield and essential oil yield of caraway, an experiment was conducted as factorial based on a randomized complete block design with three replications at the Agricultural Research Station, Ferdowsi University of Mashhad, during two growing seasons of 2012-2013 and 2013-2014. Five animal manure levels (0, 10, 20, 30 and 40 t.ha-1 cow manure) and three bulb weights (4 g) were considered as treatments. Studied criteria were plant height, canopy diameter, yield components such as umbel number per branch, umbellet number per umbel and 1000-seed weight, biological yield, seed yield, essential oil content and essential oil yield of caraway. The results showed that the simple effect of animal manure levels and bulb weights were significant on yield components, biological yield, seed yield and essential content of caraway. Interaction effect between animal manure level and bulb weight was significant on plant height, canopy diameter and essential oil yield. The highest seed yield was belonged to the maximum animal manure level with 164.20 g.m-2. Seed yield was improved up to 27% by increasing bulb weight from 4 g. The maximum essential oil yield (14.25 g.m-2) was observed for 40 t.ha-1 animal manure bulbs with >4 g.