Wild medicinal and aromatic plants (MAPs) have a high potential for organic farming and further use in medicine, food and cosmetics. The Institute for Environmental Solutions (IES) in cooperation with agriculture experts and organic farming company SIA “Field and Forest”, as well as Latvian Institute of Organic Synthesis research a potential of 9 wild spring MAPs to develop innovative technologies for organic farming.
The researchers have selected the following MAPs for this research – cowslip (Primula veris), woodruff (Galium odoratum), mezereon (Daphne mezereum), coltsfoot (Tussilago farfara), pasqueflower (Pulsatilla pratensis), lily of the valley (Convallaria majalis), ground-ivy (Glechoma hederacea), greater celandine (Chaledonium majus) and lady’s mantle (Alchemilla spp).
IES spoke to leading researcher Dr. Arta Kronberga, who showcased the latest conclusions and described further steps of the research. Read the interview below.
IES: We know that in the previous research periods the team of researchers focused on work in experimental field preparation. On what did you focus during Summer and Autumn research seasons of 2020?
Dr. Arta Kronberga (A.K.): During Summer and Autumn seasons of 2020 we continued to test the most suitable technologies for cultivation of medicinal and aromatic plats in organic farming.
“All of the researched MAPs are different. There is no such thing as one technology that would fit to all the species. We are looking for most suitable approach for each researched plant species.”
We are carrying out different activities: firs, testing of accelerated seed sprouting; second, researching of sowing for some species and planting of others; third, trying out different times of sowing and planting; fourth, testing of different types of shading systems and plant growing under agricultural film, then evaluating differences of gathered populations and effects of organic fertilisers.
IES: Plant growing under agricultural film – why this method is used in this research?
A.K.: It is a growing technology when a plant is planted, and the surface of the soil is covered with a special agricultural film that provides moisture absorbency and help plants to fight weeds. We use this technology for slow-sprouting plant species because it slows down sprouting of weeds and increases the competitiveness of plants. One of the plants we wanted to grow in the film was the ground-ivy (Glechoma hederacea), which would help to harvest the plant. This plant grows low to the ground and are covered with soil.
IES: Why did you do the tests for organic fertilizers?
A.K.: Organic fertilizers are relatively new in agriculture. There is insufficient information on fertilizers and their effects, particularly on medical plants. We don’t know how effective they are and how often should they be used? As a part of this study, we assess their effects and try to answer these questions.
IES: You mentioned that accelerated seed sprouting tests were done within this research. What conclusions can you draw from them?
A.K.: We conducted test cycles to accelerate seed sprouting of slow-sprouting plants. For example, in natural conditions lily of the valley seeds takes up to two years to sprout, because the seed needs to go through the maturity period. Such long period of sprouting is not suitable for commercial cultivation. Therefore, we have developed a method that simulates natural conditions under controlled conditions. For example, we simulate a cold period in a laboratory as cold weather naturally occurs in winter, thereby accelerating stratification. This method has shown successful results and we are preparing to present them in scientific journals.
IES: During the 2019 research season, it was concluded that the seeds of mezereon (Daphne mezereum) have been sprouting for up to two years. Have you found the most suitable method for propagating this plant?
A.K.: We have concluded that wild mezereon produces a low number of seeds that sprouts very slowly. Therefore, propagation of this plant with seeds is not suitable. We have started a new test trials for this plantlet rooting with in vitro methods. We use the information available in scientific literature to test different environments, plant hormone effects and combinations of these two factors. Plantlet rooting with in vitro method is a widely applied approach for commercial cultivation, where, under controlled conditions, a plant fragment which lacks a root is rooted.
“When we started this research, we knew that there is a lot to learn about these MAPs. It was important to find the weak points for each of the species and find smart solutions. Now, we are finding solutions that will allow us to cultivate these plants in organic farming. For example, if it is not possible to propagate mezereon with seeds, then we have to move forward and find other approaches.”
IES.: You are also carrying out an evaluation of plant development in the experimental fields. What conclusions can you share?
A.K.: During the whole research we are evaluating how each of the species develops in experimental fields in Priekuļi municipality in Latvia. We can observe differences between species and different populations within the same species. There are populations that adjust better to field conditions. We assess these differences by visual inspection of the plants, but for more precise and detailed data collection we use drone technologies. Drone overflights and data collections are carried out approximately once every two weeks at a specified height. Data is processed automatically by a specially designed algorithm capable of calculating the number of plants in each field, vegetation development and plant development capacity compared to weeds.
IES: Have you noticed any effects of climate change (e.g. raising temperature during Winter) on development of the plants?
A.K.: There is an interesting pattern that we have noticed. Some of the researched spring MAPs are blooming twice in a Spring season and once in Autumn because of the raising temperature. For example, cowslip and pasqueflower are blooming now, during October blooming in experimental fields. This phenomenon can affect the harvest. Plants are simply wasting their energy and are not able to bloom again in the Spring. We reached this conclusion this Spring when plants that bloomed in Autumn 2019 did not bloom in Spring 2020.
IES: How does Latvian Institute of Organic Synthesis (OSI) contribute to this research?
A.K.: Researchers of OSI provide very important input to this research, as they provide an insight into the value of plants grown in experimental fields. OSI researchers are currently conducting 3 major trials:
Chemical analysis of MAPs. OSI researchers are doing chemical analysis of MAPs to evaluate the composition of the active substances. They have already identified plants with the most valuable chemical composition and thus, it would be worth to research them further.
Effects of plant extracts on cells. OSI is currently studying the effects of plant extracts on cells, such as cell growth. Researchers are growing cells of living organisms and evaluating cell development by adding extracts of the 9 MAPs. While we can research the composition of different active compounds in the researched plants, OSI researchers can evaluate if these substances are suitable for further use in medicine, food and cosmetics.
Alkaloid level measurements in MAPs. MAPs contain different alkaloid groups and some of them are poisonous. OSI researchers are assessing the levels of alkaloids in the researched species to evaluate if they are useful for further use in medicine, food and cosmetics.
IES.: What kind of preparations do you intend to do before the Winter?
A.K.: At the end of the vegetation season, we will carry out an accurate inventory of plants in all the experimental fields so that we can compare differences before and after the Winter season. These data, combined with the recording of metrological conditions, will provide information on how wild plants survive Winter in commercial farming conditions.
The research is a part of the project “Innovative solutions for growing technologies and applications of spring medicinal and aromatic plants” (Nr. 126.96.36.199/18/A/043). It is supported by European Regional Development Fund, as a part of Measure 188.8.131.52 “Industry-Driven Research” of specific objective 1.1.1 “To increase the research and innovation capacity of scientific institutions of Latvia and their ability to attract external funding by investing in human resources and infrastructure”.
More about the project here.