Hydroponic cultivation of kok-saghyz and krim-saghyz on a peat substrate for natural rubber production

Natural rubber is currently obtained primarily from Hevea brasiliensis. Due to the dependence of natural rubber production on only one plant species, climate changes, and the spread of fungal diseases, it is relevant to find alternative sources. The best alternatives to Hevea brasiliensis include rubber dandelions Taraxacum kok-saghyz Rodin, Taraxacum hybernum Steven, and Taraxacum pobedimovae Schischk, as well as several others. Due to the large number of problems arising in the cultivation of rubber-bearing dandelions in soil, this work was aimed at studying their hydroponic cultivation. The tested technology for growing rubber-bearing dandelions used a standard hydroponic system, hard soil (neutral peat), and 1/8 Hoagland-Arnon solution, as well as Phytosporin-M (Bacillus subtilis) and Trichoderma viride. The highest wet and dry weights of roots were found in hydroponically grown Taraxacum kok-saghyz, which were ten times higher than those of plants cultivated in soil. The highest rubber content per dry weight of roots was found in hydroponically grown Taraxacum pobedimovae. The best rubber yield per the volume of used peat was observed in hydroponically grown Taraxacum kok-saghyz and Taraxacum pobedimovae; in the dandelions grown in soil, this parameter was found to be an order of magnitude lower. Only Taraxacum pobedimovae and Taraxacum hybernum produced fully mature seeds under hydroponic conditions. Taking the accumulation of root biomass and rubber into account, as well as seed production, Taraxacum pobedimovae is preferred for hydroponic cultivation.