Purpose. To determine the features of the leaf surface area formation and the dynamics of growth of the vege­tative mass of various sainfoin species depending on the influence of mineral fertilizers and inoculation. Methods. Field, laboratory, statistical. Results. In the course of experimental studies, the morphological features of plants in the process of growth and development of various sainfoin species were studied. As our studies showed, all sainfoin species had different plant densities, which accordingly affected the leaf surface area. In the budding phase, the leaf surface area of plants of the first year in continuous cultivation ranged from 17.01 to 24.3 thousand m2/ha on average over three years; in particular, from 18.06 to 24.3 – for common sainfoin; 17.6–20.5 – for transcaucasus sainfoin and 17.1–20.3 thousand m2/ha – for sand sainfoin. The maximum leaf surface area of the plants of the first year of cultivation, regardless of its species, was observed during flowering with the application of complete mineral fertilizer (N45P60K90). In areas without fertilizer this figure was much lower. In the experiments, an increase in the leaf surface on all three studied species and sainfoin varieties from the first to the third year of their cultivation was clearly observed. According to the results of gross productivity for 2 mowings, it was found that common sainfoin forms the maximum increase of top with complete mineral fertilizer and seed inoculation – 43.03 t/ha. Conclusions. The productivity of sainfoin crops depended mostly on the application of complete fertilizer at a dose of N45P60K90 + inoculation of seeds. To a much lesser extent, the species of sainfoin and the cutting height of the first mowing of the grass stand affected its productivity. It was revealed that the greatest dynamics of vegetative mass growth was observed in common sainfoin, and the smallest was recorded in sand sainfoin.

Purpose. Developing technology for clonal micropropagation of peppermint (Mentha piperita L.) plants of Ukrainian breeding based on the complex of methods of isolated tissue and organ culture in vitro. Methods. During the experiment, such methods as isolated tissue and organ culture in vitro, clonal micropropagation, detached scion grafting, chemotherapy with adding of virucide Ribavirin to the nutrient medium, biometric and statistical ones were used. Results. The stepped procedure of sterilization that we have developed allows to receive 88–100% of sterile explants. For M. piperita L. introduction into culture and clonal micropropagation, Murashige and Skoog (MS) nut­rient medium appeared to be optimal supplemented with 6-benzylaminopurine (0.75 mg/l), adenine (0.05 mg/l), indole-3-acetic acid (IAA) (0.05 mg/l) and gibberellic acid (0.5 mg/l) on which the reproduction ratio on the 28th day ranged between 1:7 and 1:15. For recovery of plants from viral infection, virucide Ribavirin at concentration of 10 mg/l was added to the nutrient medium. The proposed nutrient medium for rhizogenesis, that contained IAA (0.5 mg/l) and indole butyric acid (IBA) (0.5 mg/l), allows to obtain the frequency of rhizogenesis up to 84–100%. Regenerated plants were adapted to the conditions in vivo on substrate peat : universal soil : perlite : sand in the ratio 2:1:1:1. The survival rate for peppermint varieties amounted to 96–100%. Conclusions. Biotechnological scheme was developed that permits to get healthy, purebred planting material and intensively propagate plants for supplying breeding programs of the Experimental Station for Medicinal Plants of the Institute of Agroecology and Environmental Management of the National Academy of Agrarian Sciences of Ukraine, among which such varieties as ‘Lebedyna pisnia’ and ‘Ukrainska pertseva’ were selected as the most promising for clonal micropropagation.