Modifying the Growing Media and Bio Stimulants Supply for Healthy Gerbera (Gerbera jamesonii) Flowers

Abstract Gerbera ( Gerbera jamesonii ) cv. Jaguar Yellow is an ornamental plant of the Asteraceae family. Ordinarily, farmers use expensive materials such as peat moss as a media substrate in gerbera production, in addition to application high nitrogen fertilizers. Therefore, the current study was designed to assess the yield and quality changes of gerbera flowers owing to utilizing environment-friendly inputs under unheated plastic greenhouse conditions for two seasons of 2017/18 and 2018/19. The experiments were laid out in a randomized complete block design with 3 replicates, each replicate involved 5 pots per treatment. For preparing the soil substrate mixtures, four substances were used which involved peat moss (P), sand (S), vermicompost (V), and compost (C). P + S, P + S + V and P + S + C were assembled whether with or without Azotobacter + Azospirillum as bio stimulant (Bio) addition to obtain six combinations. Results showed that P + S + V + Bio was the effective practice for enhancing gerbera plant height, leaf width, root weight plant plant-1 and leaves weight plant-1. Also, P + S + V + Bio produced the maximum values of leaf chlorophyll, nitrogen, phosphorus, and potassium contents. The differences in flowering initiation between P + S and each of P + S + V, P + S + V + Bio, P + S + C and P + S + C + Bio were not significant. P + S + V + Bio (for flowering duration and flower yield), in addition to P + S + V (for flowering duration) recorded the highest values in both seasons.