The geometric shape of a plant and its components depend on the allocation of absorbed nutrients and substances to a growing organ. In turn, the overall outcome is influenced by genetics and local environmental conditions. The relationship between different components of an organ can be shown with the help of allometry. To determine the effects of organic fertilizers on morphological traits and yield of basil, this research was conducted as a factorial experiment based on a Completely Randomized Design (RCD) with three replication-s under controlled conditions. Experimental factors were basil ecotypes (green and purple) and organic fertilizers (cow manure, vermicompost, sulfur granular compost, and control). Results indicated that the highest values of plant height, fresh and dry weight of lateral branches, leaf count, leaf area, leaf fresh and dry weight, and plant biomass were found in green basil when vermicompost was applied. In contrast, the lowest mean values of these parameters were observed in the control. The application of vermicompost, cow manure, and sulfur granular compost caused increases of 30, 29, and 28% in the plant biomass of purple basil. Meanwhile, they caused increases of 61, 49, and 28% in the plant biomass of green basil, respectively. Also, the fitted experimental allometric relationship indicated a significant correlation between average leaf count and average leaf area (r2=0.95). Allometric relations-hips between root and shoot dry weight also indicated a more symmetric growth of these two parameters in green basil, compared to purple basil. Therefore, the analysis of growth relationships between plant components and production could be evaluated based on morphological components (i.e. leaf count, leaf area, and root dry weight as well as shoot dry weight), and allometric equations.

Keywords