Effect of Vermicompost Application on Plant Growth Characteristics in Saffron (Crocus sativus L.) Cultivation

Abstract

The physical and chemical properties of soil play an important role in plant growth and health influencing mainly the quantity and quality of root and shoot growth via the availability of nutrients and water. Different Vermicompost-Soil mixture ratios (w/w) in addition to pure soil and pure vermicompost were used as growth media in this study. These media are as follows: V0 (0% Vermicompost + 100% Soil), V10 (10% Vermicompost + 90% Soil), V25 (25% Vermicompost + 75% Soil), V50 (50% Vermicompost + 50% Soil), V75 (75% Vermicompost + 25% Soil), and V100 (100% Vermicompost + 0% Soil). Results showed that all vermicomposting media caused an increase in plant height than pure soil medium.  Active shoot, leaf, and flower number per plant showed an increasing tendency with the vermicomposting substrate but these results did not show statistical importance. Although stigma fresh and dry weight tended to increase with increasing vermicompost ratio in the soil statistically, the media shared the same statistical groups, pure vermicompost significantly decreased the parameters. The chemical properties of the growth media before-sowing and after-harvest were also analyzed, and it was observed that the amount of organic matter in the growing medium increased after harvest while the nitrogen concentration decreased. With the increase in vermicompost ratio in the soil, the fiber-forming and color matting of the tunics also increased statistically. Considering that the most important reasons for growing saffron are stigma and bulb yield, it is seen that vermicompost application does not have a statistical effect in terms of the fresh, and dry weight of stigma between pure soil and vermicompost-soil mixtures besides the negative effect of pure vermicompost. In addition, although V25, and V50 applications seem to be superior to lesser and higher vermicomposting medium in total corm yield, the fact that V0 (%100 Soil) gives the best result in terms of dry matter has revealed the unnecessariness of vermicompost application.