Abstract:
Abstract: Panax notoginseng is a type of well-known traditional Chinese medicine. The root of Panax notoginseng has many healing effects on the blood system, cardiovascular system, brain, vascular system, nervous system, metabolism, and immune regulation. As the main herbal producing area, Yunnan province has planted Panax notoginseng from 4 300 hm2 in 2006 to 20 000 hm2 in 2016, increasing by 3.7 times. Output quantity has nearly doubled increased from 3.78×106 kg in 2006 to 7×106 kg in 2016. Nevertheless, the per unit area yield of Panax notoginseng decreased from 900 kg/hm2 in 2003 to 350 kg/hm2 in 2016, released by a current comparative analysis. Two reasons can contribute to the decrease: 1) The unreasonable management of water and fertilizer can lead to frequent occurrence of Panax notoginseng diseases, due possibly to the growth of Panax notoginseng is sensitive to soil moisture and nutrients, liking shade and wet environment. 2) 3-7 years are highly demanding for Panax notoginseng from planting to harvest. Continuous cropping obstacles in the planting process are also leading to the decreased yield with the increased incidence of disease. To increase Panax notoginseng yield, large amounts of chemical, organic and foliar fertilizers are used to promote Panax notoginseng growth, while large amounts of pesticides are sprayed to control the planting diseases. This study aims to investigate the effects of irrigation frequency and fertilizer amount on active component accumulation, and morbidity of Panax notoginseng. The native 2-year-old Panax notoginseng was chosen as experiment material. A field experiment was conducted during growing seasons in an experimental Panax notoginseng base in Kunming University of Science and Technology. Four levels of irrigation frequency were set: W1 (3 d irrigation once), W2 (5 d irrigation once), W3 (7 d irrigation once), and W4 (9 d irrigation once). Two fertilizer levels were F1 (75 kg/hm2) and F2 (150 kg/hm2). A complete combination was adopted with a total of 8 treatments. The results showed that with the reduce of irrigation frequency, the photosynthetic rate and transpiration rate of Panax notoginseng increased at first and then decreased, and the photosynthetic rate maximum under W2 treatment. The variation trends of plant height, stem diameter, leaf length and leaf width under various treatments were roughly the same, all of them indicating the maximum was obtained in the fruit stage,and the overground part of Panax notoginseng stops growing. The water potential of Panax notoginseng leaves first increased and then decreased, with the reduce of irrigation frequency, indicating the largest was achieved under W2 treatment. Under the combination of sub low-frequency irrigation and high-fertilizer W3F2, the accumulation of active components in Panax notoginseng root was the largest (1 084.93 mg/kg). In addition, with the reduce of irrigation frequency, the incidences of root rot of Panax notoginseng and black spot disease were the highest (15.79% and 3.41%, respectively) under the condition of high-frequency irrigation W1. The incidence of dry leaf disease was the lowest, only 1.11%. A combination treatment of sub low-frequency irrigation W3 (7-day irrigation once) and high-fertilizer F2 (150 kg/hm2) under the conditions of micro-sprinkling irrigation was suitable for the accumulation of effective components in Panax notoginseng roots was high, with a low incidence of disease. This finding can provide an important theoretical guidance to optimize the water and fertilizer management of panax notoginseng, and thereby to realize its green and sustainable development.