Influence of NPK levels on growth and yield of Stevia rebaudiana Bertoni under hills of Uttarakhand

Abstract

A field experiment was carried out at CSIR-Central Institute of Medicinal and Aromatic Plant Research Centre Purara, Bageshwar, Uttarakhand, India during 2014 and 2015 in sandy loam soil on Influence of NPK levels on plant growth and yield of Stevia rebaudiana Bertoni under lower hills of Kumaon Uttarakhand were tested in a randomized block design with factorial concept in three replications. Four harvestings were taken in a year. Stevia were treated with three doses of nitrogen (100,200,300 N kg/ha), three doses of phosphorus (60,120,180 P2O5 kg/ha) and two levels of potassium (80,160 K2O kg/ha). Pooled results indicated that significantly higher dry leaf yield was obtained with nitrogen @ 300 Kg/ha (45.68 t/ha) and it was on par with 200 kg/ha (43.76 t/ha). Phosphorus @ 180/ha recorded significantly highest dry leaf yield (40.68 t/ha) and it was on par with 120 kg/ha (43.40 t/ha). Potassium @ 160 kg/ha recorded dry leaf yield of 43.12 t/ha and it was comparable with potassium @80 kg/ha (41.84 t/ha). The growth parameters viz., plant height (cm), number of branches per plant and number of leaves per plant were significantly higher with nitrogen, phosphorus and potassium @ 300 kg/ha, 180 kg/ha and 160 kg/ha, respectively which were on par with 200 kg/ha, 120 kg/ha and 80 kg/ha respectively. In pooled data nitrogen N3 i.e., 300 kg/ha recorded the highest B:C (4.60) which was on par with nitrogen @ N2 i.e., 200 kg/ha (4.34), but significantly higher than N1 i.e., 100 kg/ha (3.38). Phosphorous P3 i.e., 180 kg/ha resulted in higher B:C (4.61) which was on par with P2 i.e., 120 kg/ha (4.50). Potassium level influenced the B:C non-significantly. Significantly lowest B:C was recorded with absolute control in pooled data (2.19). Nutrient level of 300:180:160 kg/ha NPK applied in equal splits to four harvestings in a year has been considered as an economically optimum level of nutrients for stevia.