Estimating Fritillaria thunbergii Miq. yield, quality, and potassium use efficiency in response to potassium application rate

Abstract

There is a high market demand for the dried bulb of Fritillaria thunbergii Miq. because of its use to treat airway inflammatory and endocrine system diseases. Although F. thunbergii requires more potassium than nitrogen and phosphorus during development, the response of F. thunbergii to potassium has rarely been studied. Field experiments were conducted in 2016/2017 and 2017/2018 with two F. thunbergii cultivars under six levels of potassium fertilization (0, 40, 80, 120, 160 and 200 kg K2O ha−1) to investigate the effects of potassium application on F. thunbergii yield, quality, and potassium utilization efficiency. Results showed that potassium fertilization increased the bulb yield, bulb quality (peimine and peiminine content), and net income by 6.4–23.8 %, 2.1–26.6 % and 47.7–205.4 %, respectively. More biomass and potassium were partitioned to underground parts when potassium application increased. The yield and quality of the bulb were positively correlated with potassium accumulation in the underground part. The economic benefit of F. thunbergii is stable at 120–160 kg K2O ha−1, while the potassium utilization efficiency was reasonable at 80–120 kg K2O ha−1. In summary, potassium application is an effective strategy to simultaneously improve bulb yield and quality in F. thunbergii. Considering the economic and environmental benefits, a potassium application rate of 120 kg K2O ha−1 is optimal for F. thunbergii cultivation.