Development and implementation of an innovation for the production of garden rhubarb (Rheum × hybridum) with improved health-promoting, sensory and processing characteristics

The climatic conditions of Podkarpacie (length of the vegetation period, average daily temperatures, amount of precipitation) and clay soils are conducive to the cultivation of rhubarb, but the main incentive for farmers is the possibility of increasing the profitability of production.

• Due to early yielding, this vegetable is the first source of income. Rhubarb is cultivated on fragmented plots with large slopes, hence it is classified as a specialist crop.
• The availability of high-quality seedlings to farmers will allow them to meet the requirements of ecological and sustainable cultivation, increase the health of the plantation, increase yields and the quality of the raw material obtained. It will also allow for optimal use of the cultivation area and reduction of the use of resources: fertilizers, fuel, wear of equipment and human labour.
•  Thanks to the project, errors related to the cultivation of rhubarb types not adapted to the conditions of organic and sustainable cultivation in Podkarpacie will be avoided.
• For farmers in Podkarpacie, the cultivation of rhubarb is a great capital, which will be maintained and developed thanks to the project.
• Cultivation of rhubarb, a plant rich in bioactive compounds (phenolic acids, anthocyanins, flavonols, vitamin K) on a commercial scale is an important source of raw materials for direct consumption, processing industry (frozen food, wine, a component of jams, juices, natural food preservative, gelling agent) as well as the cosmetics and pharmaceutical industries.

The wide availability of farmers to the unique seedlings (high health, physiological condition, genetic homogeneity) of valuable selections and red-tailed rhubarb varieties sought after on the market, obtained thanks to the project, will allow for an increase in yields and the quality of the raw material obtained, as well as an increase in the area of cultivation. Thus, the availability of raw materials with high quality parameters for the Polish processing industry will increase. Certainly, the operation carried out will be extremely helpful in ensuring a stable and sustainable food supply.

The aim of the project is to develop and implement innovations in the production of sought after varieties and valuable selections of garden rhubarb (Rheum × hybridum) in Podkarpacie, affecting the increase in yield and improvement of the quality parameters of plants (high level of bioactive compounds, increased resistance to pathogens, abiotic stress) using a unique seedling produced in vitro in accordance with the principles of Good Practice with the use of biostimulators, natural plant protection products and light color modification as well as organic cultivation on a plantation.

The operation is also aimed at the selection of appropriate rhubarb varieties adapted to ecological and sustainable cultivation in the soil and climatic conditions of Podkarpacie, allowing for an increase in competitiveness and demand.

Project activities

The aim of the project is to develop and implement innovations in the production of sought-after varieties and valuable selections of garden rhubarb (Rheum × hybridum) in Podkarpacie, affecting the increase in yield and improvement of the quality parameters of plants (high level of bioactive compounds, increased resistance to pathogens, abiotic stress).

• The goal will be achieved by using a unique seedling produced using in vitro cultures, biostimulators and modifying the light spectrum. Plants selected on the plantation for the desired trait (high level of anthocyanins, size of petioles, yield) of different types of rhubarb - 'Raspberry', 'Lider', 'Karpow Lipskiego', 'Goliath', ˈFrambozenˈ obtained from sowing or division of the rootstock will be tested on the presence of viruses and propagated in vitro.
• In order to increase the synthesis of phenolic substances (affecting resistance to pathogens) and photosynthetic activity, the acclimatization of microseedlings to ex vitro conditions will be carried out in accordance with the principles of Good Practice (Journal of Laws 06.194.1436 www.mz.gov.pl), with the use of biostimulators and modification of the light spectrum.
• It is also planned to develop a comprehensive program for the protection of rhubarb micro-seedlings against foliar pathogens developing in high humidity conditions during acclimatization. The assumption of this program is to minimize or completely eliminate the use of chemical plant protection products.
• Determining the optimal conditions will ensure that the seedling will have a well-developed rhizome with numerous adventitious roots and an induced system of resistance to abiotic and biotic stress in later cultivation, which will be carried out according to the principles of organic farming under the supervision of an authorized certification body.
• On plantations, it is planned to create experimental plots on which research and development works will be carried out, the purpose of which is to assess the subsequent impact of seedling type and genotype on the height and quality of the yield. This will help to avoid errors related to the cultivation of varieties not adapted to ecological and sustainable cultivation in the soil and climatic conditions of Podkarpacie.

The main benefits of the project

There is currently a shortage of rhubarb raw material in the market. This is due to the liquidation of unprofitable rhubarb plantations with green petioles in previous seasons. The currently observed trend in consumer preferences indicates the consumption of more and more high-quality, and above all, organic food. They are looking for e.g. products with a high content of phenolic compounds that have antioxidant, anti-inflammatory and anti-cancer properties. Hence, red-tailed rhubarb, containing a high level of anthocyanins (cyanidin-3-rutinoside and cyanidin-3-glycoside) and flavonoids, has recently gained a lot of interest. 

• The nutrient content is greatly influenced by the variety, as well as the climate, soil and cultivation method. It has been shown that in organic production, plants, by activating their natural defense system against diseases and pests, synthesize more phenolic compounds that perform defensive functions in plants and at the same time are pro-health for humans.
• In Podkarpacie, there are relatively good conditions for growing rhubarb using the organic method, but the main incentive for farmers is the possibility of increasing the profitability of production.

Another big problem is the availability of high-quality seedlings of the red-tailed rhubarb varieties sought after, as well as valuable selections.

• Due to the low efficiency of rhubarb propagation by the traditional method by dividing the carp, generative reproduction is commonly used, which results in obtaining very diverse offspring (without anthocyanins, numerous and thin, non-commercial petioles). Propagation by division of carp is burdened with the transmission of viruses.
• In addition, commercially available material is often affected by various fungal pathogens. Establishing a plantation based on uncertain material may result in low productivity and commercial potential of the obtained raw material.

The proposed project is an undertaking aimed at solving the presented problems through the wide availability of farmers to a unique seedling with high health and physiological condition of sought-after and valuable rhubarb selections obtained using in vitro cultures, biostimulators and modification of the light spectrum, as well as the selection of appropriate rhubarb varieties adapted to organic cultivation and balanced in the soil and climatic conditions of Podkarpacie.

The assumption of the project is also to increase the biological, sensory and processing characteristics by eliminating the use of chemical plant protection products at the stage of acclimatization of microseedlings for ex vitro growth and subsequent cultivation on the plantation.

Practice summary

1. The wide availability of farmers to a unique seedling (high health, physiological condition, genetic stability) of valuable selections and red-tailed rhubarb varieties sought after on the market will allow to increase the acreage of crops and their profitability by improving the health of plantations, increasing yields, optimal use of cultivated areas, reducing treatments agrotechnical.
2.  Limiting the use of plant protection products in the production of seedlings and during growth on plantations will increase the biological, sensory and processing characteristics of the product obtained.
3. Ensuring an adequate level of food production is one of the most important problems of the 21st century.
4. The creation of experimental plots will allow to select the best selections/varieties of rhubarb for organic cultivation in Podkarpacie.
5. Cultivation of rhubarb rich in bioactive compounds on a commercial scale will increase the availability of a high-quality product for consumers as well as for the processing and pharmaceutical industries.

Additional comments

Members of the Operational Group will establish close cooperation through joint participation in the project. Bridges will be created between science implementing knowledge and modern technologies in agriculture and farmers who will apply these solutions in practice. Close cooperation in the implementation of research goals between farmers and scientists will increase the level of farmers' knowledge of modern methods of production, but will also allow the application of this knowledge in their current activities. 

An element of the project will be direct advice and exchange of information on the importance of establishing plantations with the use of high-quality seedlings multiplied in vitro and modern techniques for assessing the obtained raw material in terms of the content of bioactive substances. 

As a result of the project, recommendations will be developed on the production of high-quality rhubarb propagation material in accordance with the principles of Good Practice, as well as a comprehensive program for the protection of rhubarb microseedlings during the stage of acclimatization to growth in ex vitro conditions.