effects of biological fertilizer and vermicompost on vegetative yield and essential oil of basil (ocimum basilicum l.) under mashhad climatic conditions

in order to study the effects of vermicompost and biological fertilizers on vegetative yield and essential oil of basil (ocimum basilicum l.), an experiment was conducted based on a complete randomized block design with nine treatments and three replications at mashhad during growing season of 2009-2010. the treatments were: 1) vermicompost, 2) nitroxin (included: azotobacter sp. and azospirillum sp.), 3) biophosphorus (included: pseudomonas sp and bacillus sp), 4) vermicompost+ nitroxin, 5) vermicompost+ biophosphorus, 6) nitroxin+ biophosphorus, 7) vermicompost+ nitroxin+ biophosphorus, 8) chemical fertilizer (n.p.k), 9) control (no fertilizer). two harvests were cut at similar phonological stage during growing season. the results showed that at both cutting of basil, biological fertilizer combined with vermicompost were better compared to chemical fertilizer and control. in the first harvest, the highest fresh (11377.8 kg.ha-1) and dry yields (1895.6 kg.ha-1) obtained in vermicompost+ nitroxin+ biophosphorus treatment. also, vermicompost+ nitroxin and vermicompost+ biophosphorus produced the highest leaf dry yield (1164.7 and 1166.8 kg.ha-1 respectively). in second cutting, the highest fresh yield (11333.3 kg.ha-1) obtained in vermicompost+ nitroxin+ biophosphorus and the highest dry yield (2017.8 kg.ha-1) and leaf dry weight (1103.4 kg.ha-1) obtained in vermicompost+ nitroxin treatments. in both cuttings, the highest essential oil percentage obtained in control. the results of this study showed that vermicompost and bio fertilizers alone or in combination had no effect on essential oil but increased vegetative yield.