Effect of fertigation on Stevia (Stevia rebaudiana) under drip irrigation

Abstract

A field experiment was conducted at the Directorate of Water Management, Bhubaneswar (Odisha) during rabi seasons of 2005–06 and 2006–07 to study the effect of drip irrigation regimes and fertigation levels on stevia (Stevia rebaudiana, Bertoni), grown in rice fallow. The treatments included three irrigation regimes (I1- drip irrigation at 100% PE, I2 at 80% PE and I3 at 60% PE) and three fertility levels (F1-100%, F2 – 75% and F3 - 50% recom mended dose of 110-45-45 kg N-P2O5-K2O/ha) with an extra treatment as control having surface irrigation with soil application of fertilizers were tested in a factorial randomized block design with three replications. Pooled data of two years showed that drip fertigation improved fresh leaf by 4.9%, dry leaf by 4.0% and total biomass yield by 2.04% over conventional surface irrigation with soil application of fertilizer. Irrigation through drip at 100% PE produced maximum fresh leaf (8.95 t/ha), dry leaf (2.74 t/ha) and total biomass yield (34.44 t/ha). Application of 100% RD (F1) gave highest quantity of fresh leaf (8.21 t/ha), dry leaf (2.53 t/ha) and biomass (33.50 t/ha) compared to 75% RD and 50% RD. Application of irrigation at 100% PE with 100% recommended dose of fertilizer produced 9.13 t of fresh leaf 2.90 t dry leaf and 35.0 t biomass yield per hectare and; improved glycoside contents. However, the magnitude of N, P and K contents in both soils and plants have also been enhanced with 100% fertilizer application of N, P2O5 and K2O (110-45-45 kg/ha) compared to lower levels.