EFfect of different vermicompost from various organic sources on productivity and economics of sunflower (helianthus annuus l.) variety co 4.

Field experiment was conducted at the experimental farm, Department of Agronomy, Annamalai University, during February – May (2012) to study the effect of different vermicompost from various organic sources on productivity and economics of sunflower variety CO 4. The experiment with ten treatment combinations were laid out in randomized block design and replicated thrice. The ten treatment includes absolute control, recommended dose of fertilizer alone and graded dose of fertilizer nitrogen along with different organic composts and vermicompost. All the treatments exerted significant influence on growth and yield attributes and oil content of sunflower over the control. Application of 75% recommended dose nitrogen (RDN) + pressmud vermicompost @ 2.5 t ha-1 significantly recorded the higher plant height (169.80 cm), leaf area index (4.80) seed yield (1825.77 kg ha-1) oil content (40.47%) and oil yield (738.89 kg ha-1). Recommended dose Nitrogen (50 kg N) alone recorded lower seed yield, oil content and oil yield among the treatment combinations. However, it was significantly higher than control (no fertilizer and no organic manure). The next in order of ranking was 75% RDN + sewage sludge vermicompost @ 2.5 t ha-1. The benefit cost ratio (2.99) was also found to be higher with 75% RDN + pressmud vermicompost @ 2.5 t ha-1. Based on the above, it could be concluded that, 75% recommended dose nitrogen (RDN) + pressmud vermicompost @ 2.5 t ha-1 would help to increase productivity and profitability of sunflower under Cauvery delta region of Tamil Nadu.