Effects of shade regimes and planting geometry on growth, yield and quality of the natural sweetener plant stevia (Stevia rebaudiana Bertoni) in north-western Himalaya

• Published in: Archiv für Acker- und Pflanzenbau und Bodenkunde 2013-07, Vol.59 (7), p.963-979
• Main Authors: Kumar, Rakesh, Sharma, Saurabh, Ramesh, Kulasekaran, Singh, Bikram
• Format: Article
• Language: English
• Subjects: planting geometry; rebaudioside-A; shade stress; Stevia; Stevia rebaudiana; stevioside; yield
• ISSN: 0365-0340; 1476-3567
• DOI: 10.1080/03650340.2012.699676

During 2008 and 2009, field experiments were conducted at the research farm of CSIR-Institute of Himalayan Bioresource Technology, Palampur, India to assess the effect of shade levels (no shade, 25% shade, 50% shade, 75% shade) and plant geometry levels [30 × 15 cm (north-south, N-S), 45 × 10 cm (N-S), 30 × 15 cm (east-west, E-W) and 45 × 10 cm (E-W)] on the growth, yield and quality of stevia. Plant development was fastest in controls and slowest in stevia plants growing at minimum light (75% shade). These plants showed delayed bud formation and flowering. Significantly, higher dry leaf yield was recorded when the crop was grown under 25% shading than under 50 and 75% shade. Total steviol glycosides content decreased with increasing shade levels. All shade levels resulted in the same leaf-to-stem ratio, which was significantly higher than that obtained under ambient light. Plant geometry significantly affected the number of leaves and leaf dry weight plant -1 . During both years, dry leaf weight was highest in the wider row spacing (45 × 10 cm) than in the narrow row spacing (30 × 15 cm). Stevia spaced at 30 × 15 cm in an E-W direction recorded significantly higher total steviol glycosides at 2 months after transplanting (MAT).