Harvesting regimes to optimize yield and quality in annual and perennial Stevia rebaudiana under sub-temperate conditions

Uses of the perennial crops have been proven to increase the sustainability in agriculture. However, information about the relative efficiency of annual versus perennial stevia (Stevia rebaudiana) under different harvest regimes is unknown in the sub-temperate region of western Himalaya in India. The harvesting time of stevia is generally controlled by growth behavior and accumulation pattern of the steviol glycosides (SGs). Our objectives were to standardize the harvesting regimes in both the cropping modes for higher yield and quality of stevia leaf. Thus a field experiment with six treatment combinations comprising two life cycles (annual and perennial) and three harvest regimes (single-cut, double-cut and triple-cut) was conducted. The total dry leaf yield was in the range of 1.40-4.11 t ha−1, and significantly (P ≤ 0.05) highest dry leaf yield was recorded with the perennial stevia under three-cut management system (PH3) but remained statistically at par with PH2 (perennial with two-cut). However, PH2 produced maximum SGs (10.29 g plant−1). The results of Principle component analysis reveal that PH2 and PH3 are equally effective and suitable management practices for dry leaf and SGs yield. Thus, our results suggest that the perennial stevia with two-cut management system is suitable for sustaining the stevia production in this condition.