The dissertation covers the theoretical and practical issues related to the implementation of an important scientific task - the study of the elements of the technology of the cultivation of paulownia in the conditions of the Forest Steppe of Ukraine.
The survival rate of paulownia plants on the control variants of the study was the lowest - 74.2%. At the same time, the main factor in ensuring a better level of plant survival in the variants without improvement was the use of MARS EL cryoprotectant (0.5 l/ha), which increased viability to 80.2%. The best variants of the study in terms of the percentage of plants that survived were observed precisely for the application of organic fertilizer "Vermicompost" (400 kg/ha) and treatment of seedlings with cryoprotectant MARS EL (0.5 l/ha) - 89.8-90.2%.
At the time of flowering of the Pavlovian in the first year of vegetation, taller plants were obtained using organic fertilizer of the "Vermicompost" variant (400 kg/ha) in combination with MARS EL cryoprotectant (0.5 l/ha). With this basic combination of plant treatment factors, additional preparations for foliar feeding Kvantum-AminoFrost (1.5 l/ha) or SMARTGROW RECOVERY (2.0 l/ha) provided the best indicator according to the study - 142.0 and 143.0 cm, respectively.
In the phase of full formation of the crown, in the first year of vegetation, the best content of chlorophyll groups was found in the options of fertilizing plants with organic fertilizer "Vermicompost" (400 kg/ha), applying treatment of plants with cryoprotector MARS EL and applying foliar fertilization Quantum-AmiNoFrost (1.5 l/ha) – 2.20 mg/kg. At the same time, it was found that foliar treatment of plants with the researched drugs (Quantum-AmiNoFrost and SMARTGROW RECOVERY) does not significantly affect the growth of the group of chlorophylls b.
At the time of flowering, in the first year of vegetation, the total content of chlorophylls in the control variant was only 3.57 mg/kg, while on average, according to the experiment, indicators of 4.1 mg/kg were obtained. While the option of fertilizing plantations with organic fertilizer "Vermicompost" (400 kg/ha) and using plant treatment with cryoprotector MARS EL (0.5 l/ha) in combination with foliar fertilization SMARTGROW RENEWAL (2.0 l/ha) provided the maximum - 4.54 mg/kg.
In the second half of the growing season of 2021, according to the content of dry matter in paulownia plants, it was determined that the best combination of factors of the experiment was on the options of fertilization with organic fertilizer "Vermicompost" (400 kg/ha) and treatment of plants with cryoprotector MARS EL (0.5 l/ Ha). Under these experimental conditions, the dry matter content was 52.2%. At the same time, on these options, 52.6% of dry matter was obtained with the application of foliar top-dressing Quantum-AminoFrost, and 52.8% with SMARTGROW RECOVERY treatment (2.0 l/ha).
The best values of the photosynthetic potential in 2021 were in the section of the experiment options for fertilization with organic fertilizer "Vermicompost" (400 kg/ha) and treatment of plants with cryoprotector MARS EL (0.5 l/ha). At the same time, additional treatment of crops with SMARTGROW RECOVERY (2.0 l/ha) provided the conditions for obtaining the best indicator of photosynthetic potential in the experiment - 5.46 million m2/ha.
The improvement of the net photosynthetic productivity of plants in the first year of vegetation was observed in the case of the complex action of the research factors. After all, in this case, we received a good level of plant nutrition and opportunities for them to overcome stresses arising in the process of growth and development. So, when fertilizing with organic fertilizer "Vermicompost" (400 kg/ha), as well as treating plants with cryoprotector MARS EL (0.5 l/ha) and foliar fertilizer Quantum-AmiNoFrost (1.5 l/ha), the PPF was 0.42 g /m2 per day of dry matter.
In 2022, in general, the duration of the interphase period from the appearance of leaves to the full formation of the crown was 21.0 days, and paulownia plants went through this phase more quickly in the case of their treatment with cryoprotectant MARS EL (0.5 l/ha) (for 2 days). While in the interphase period from the full formation of the crown to the formation of flowers, with an average duration of 32.9 days, the fastest development of paulownia was obtained with options for the combined use of biologically active substances - cryoprotectant MARS EL (0.5 l/ha) and foliar feeding Quantum- AminoFrost (1.5 l/ha) or SMARTGROW RECOVERY (2.0 l/ha). At the same time, the shortest period was during treatment with both drugs on variants without the influence of other factors of the experiment, as well as in the case of applying fertilizer and using a cryoprotectant.
In the second year of vegetation, the time of leaf fall, paulownia plants of the second year of vegetation had an average plant height of 623.3 cm.
