Influences of Vermicompost as a Seedling Growth Medium on Organic Greenhouse Cucumber Production

This study was conducted to determine the possibility of using vermicompost (VC) as a seedling growing medium, and its performance on production of organically grown cucumber (Cucumis sativus, 'E 32.15845') in a greenhouse. Organic seeds were grown in peat (P) (100%), VC (100%), or the mixture of both in different ratios (20, 40, 60 or 80% VC), and seedlings were grown using organic methods. Effects of treatments on seedling growth, plant growth, yield, and fruit quality were determined in the autumn of 2011 and spring of 2012. Seedlings were planted on 26 August 2011 and 5 March 2012 at a spacing of 3.57 plants m(-2). Some seedling quality parameters showed significant differences according to growing systems and seasons. Substrate containing 100% VC resulted in the shortest seedling stem length and lowest shoot fresh and dry weights in all seasons; however, this was not significantly different than 100% P in the spring. At the end of the growing season, VC amendments in different ratios produced longer plant lengths compared with peat (100%). In both seasons, 40% VC + 60% P and 100% P had the lowest shoot fresh weights, while in the spring, shoot fresh weights in the 20% VC amendment did not differ significantly from the previous two treatments. The highest total and marketable yields were observed on plants grown in 40% VC + 60% P in both growing seasons. Some fruit quality parameters were affected significantly by the growing season and treatments. Considering overall results, it was concluded that VC could be used as a portion of the seedling growing medium and that it increased the yield. Among the treatments tested, the amendment of 40% VC had promising effects on yield and biomass.