Vermicompost Effects on the Growth and Flowering of Petunia hybrida 'Dream Neon Rose'

Abstract: The effects of vermicompost of an animal manure origin on the growth and flowering of Petunia hybrida ‘Dream Neon Rose ’ grown under glasshouse conditions were determined. Petunia seeds were germinated, transplanted into media and grown-on for 150 days. The traditional base medium (control) was a mixture of 70 % farm soil and 30 % sand (v/v). Treatments were either vermicompost incorporated at 20, 40 and 60 % or sphagnum peat incorporated at 30 and 60 % into the base medium. Vermicompost had significant (P<0.05) positive effects on flower numbers, leaf growth and shoot fresh and dry weights compared to both control and peat amended media. Plant performance was best in the 20 % vermicompost medium. Further increasing the vermicompost content in the base media decreased flower numbers, leaf growth rates and shoot fresh and dry weights. Plant performance was poorest in the 60 % sphagnum peat medium. Plant tissue analysis revealed that total extractable N, P and K were highest in petunia plants grown in the 60 % vermicompost medium and were lowest in plants grown in the 60 % peat medium. Use of vermicompost tended to increase tissue Ca and Mg concentrations compared to the control. However, these trends were generally not significant at P<0.05. Fe was also highest in plants grown in the 60% vermicompost medium and was lowest in plants grown in the control medium. Zn concentrations were highest in plants grown in 60 % peat medium and lowest in plants grown in the control medium. Cu and Mn