Light-NPK synergy increases biomass, photosynthetic pigment and nitrogen content in Agastache rugosa (Fisch. & C.A.Mey.) Kuntze

Khairul Azree Rosli, . and Azizah Misran, . and Latifah Saiful Yazan, . and Puteri Edaroyati Megat Wahab, . (2024) Light-NPK synergy increases biomass, photosynthetic pigment and nitrogen content in Agastache rugosa (Fisch. & C.A.Mey.) Kuntze. Journal of Tropical Plant Physiology (JTPP) (Malaysia), 16 (2). pp. 29-44. ISSN 1985-0484

Agastache rugosa (Fisch. & C.A.Mey.) is a medicinal herb native to subtropical and temperate climates which is highly valued for its essential oils and phytochemicals in the pharmaceutical, cosmetic, and food industries. This study examined the adaptive strategies of A. rugosa in response to varying light and NPK levels. The treatments were four NPK levels which were low (NPK1, 40 mg kg ⁻¹), moderate (NPK2, 80 mg kg ⁻¹), high (NPK3, 120 mg kg ⁻¹ ) and very high (NPK4, 160 mg kg ⁻¹) nested under two light levels namely high-light (HL, 0% shade) and low-light (LL, 50% shade). We uncovered a resource allocation mechanism that optimises growth and photosynthetic efficiency through a multidimensional analysis involving biomass, photosynthetic pigment, and nitrogen contents. Highlight promoted greater biomass and pigment content across NPK treatments, with the most pronounced effects under low NPK levels, indicating enhanced nitrogen use efficiency. This suggested that strategic management of light levels could compensate for nutrient deficiencies in this valuable herb. High-light increased leaf nitrogen content in a non-linear way, implying shifts in resource allocation, which are crucial for optimising fertilisation. Principal component analysis exhibited distinct clustering patterns, highlighting the dominant effect of light on overall physiology, with NPK levels introducing a secondary gradient of variation. Our results demonstrated the complex interplay between light and NPK availability in shaping plant responses, challenging simplistic notions of productivity and proving the importance of considering multiple environmental factors in tandem. These insights advance our understanding of plant adaptation to environmental changes and offer valuable guidance for optimising cultivation practices in medicinal herb production.

Full text available from: Official URL: https://www.jtpp.org.my/volume/16_2/vol16_2_articl...

Abstract

Agastache rugosa (Fisch. & C.A.Mey.) is a medicinal herb native to subtropical and temperate climates which is highly valued for its essential oils and phytochemicals in the pharmaceutical, cosmetic, and food industries. This study examined the adaptive strategies of A. rugosa in response to varying light and NPK levels. The treatments were four NPK levels which were low (NPK1, 40 mg kg ⁻¹), moderate (NPK2, 80 mg kg ⁻¹), high (NPK3, 120 mg kg ⁻¹ ) and very high (NPK4, 160 mg kg ⁻¹) nested under two light levels namely high-light (HL, 0% shade) and low-light (LL, 50% shade). We uncovered a resource allocation mechanism that optimises growth and photosynthetic efficiency through a multidimensional analysis involving biomass, photosynthetic pigment, and nitrogen contents. Highlight promoted greater biomass and pigment content across NPK treatments, with the most pronounced effects under low NPK levels, indicating enhanced nitrogen use efficiency. This suggested that strategic management of light levels could compensate for nutrient deficiencies in this valuable herb. High-light increased leaf nitrogen content in a non-linear way, implying shifts in resource allocation, which are crucial for optimising fertilisation. Principal component analysis exhibited distinct clustering patterns, highlighting the dominant effect of light on overall physiology, with NPK levels introducing a secondary gradient of variation. Our results demonstrated the complex interplay between light and NPK availability in shaping plant responses, challenging simplistic notions of productivity and proving the importance of considering multiple environmental factors in tandem. These insights advance our understanding of plant adaptation to environmental changes and offer valuable guidance for optimising cultivation practices in medicinal herb production.

[error in script]

Item Type:	Article
AGROVOC Term:	medicinal plants
AGROVOC Term:	fertilization
AGROVOC Term:	cultivation
AGROVOC Term:	NPK fertilizers
AGROVOC Term:	light
AGROVOC Term:	biomass
AGROVOC Term:	nitrogen content
AGROVOC Term:	plant growth
AGROVOC Term:	nutrient use efficiency
Geographical Term:	Malaysia
Uncontrolled Keywords:	Agastache rugosa, biomass, chlorophyll, light, nitrogen, nutrient
Depositing User:	Ms. Azariah Hashim
Date Deposited:	16 Jun 2026 09:01
Last Modified:	16 Jun 2026 09:01
URI:	http://webagris.upm.edu.my/id/eprint/3911

Actions (login required)

View Item