Effect of fertilizer and harvesting stage on growth and bioactive compounds content of Rheum tanguticum

Abstract

Rhubarb is a popular food in Europe due to the purgative action. Cultivation is the key way to ensure sustainable development and utilization of this herbal plant. In this paper, standardized cultivation of Rheum tanguticum (a kind of rhubarb) was explored through a three-year field experiment which investigated the effect of phosphorus (P) and potassium (K) fertilizer on growth indexes, sennoside content of R. tanguticum at different harvesting stages. Results showed that P and K fertilizer significantly increased root length, root diameter and root fresh weight, the maximum root fresh weight was 894.22 g/plant. Sennoside content of three-year-old R. tanguticum applied K fertilizer was over 5.87% at each harvesting stage in the third growth cycle and it increased along with growing year. Sennoside content has no obviously increment at the same harvesting stage, it also has no positive correlation with different harvesting stages and the wilting stage > green stage > growth stage in the same year. This study demonstrated that P and K fertilizer had accelerated effect on growth of R. tanguticum at the same harvesting stage, but had no obvious influence on the sennoside content. This will provide experimental data and guidance for the standardized cultivation of R. tanguticum.

Highlights

1. The effect of different fertilizer (P, K) doses, harvesting stages and growth years on growth indexes and sennosides contents of R. tanguticum was firstly explored.

2. A modified HPLC detective method was developed to quantify the sennosides content of R. tanguticum.

3. The effect of different fertilizer doses on growth indexes of R. tanguticum was firstly explored.

4. Variation of sennoside content after applying fertilizers was firstly explored.

5. The effect of harvesting stages on growth indexes and sennosides contents was firstly explored.

Graphical Abstract

KEYWORDS:

• Fertilizer
• growth indexes
• harvesting stages
• Rheum tanguticum
• sennoside content

Acknowledgment

The author wish to thank Yanbin Shi for the help given of data collection.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Qinghai Provincial Key Research and Development and Transformation Program (2023-NK-133); Gansu Provincial Department of Agriculture and Rural Areas Foundation to Prof. Yuan Chen for a Chief Expert of Traditional Chinese Medicinal Industry in Modern Agricultural Industry System (GARS-ZYC-1), Technology Innovation Guide Project of Gansu Province, China (22CX8NA002), Innovation and entrepreneurship training program for college students of Linyi University.