Biometric parameters of fruits and seeds of Paulownia tomentosa collected from trees growing in soil and climatic conditions of different geographical locations of Odesa, Zakarpattia (Mukachevo) and Lviv regions of Ukraine, as well as technical and absolute germination, germination energy, mean germination time and weight of 1000 seeds, were studied. The effect of different temperatures on seed germination in soil was evaluated under two temperature regimes. The influence of the duration of pre-soaking on seed germination was also determined. Pre-soaking
of seeds in water and solutions of five different stimulants on germination in soil was also investigated. It has been found that in the conditions of Odesa region, the species formed larger fruits and the seeds were characterized by significant rate and uniformity of germination. Lowering of germination temperature caused a decrease in germination energy, laboratory and absolute seed germination, and increased the mean germination time of seeds. Pre-soaking of seeds increased significantly germination rate and its duration was associated with the parameters: germination energy, technical and absolute germination. Among the three seed collections, the highest technical germination was recorded for seeds from Lviv region. The seeds from Odesa region had the highest germination energy. The seeds were characterized by high germination rate in soil regardless of the geographical location of seed collection under the conditions of Ukraine. The highest germination in soil was found for seeds, collected in Lviv. Temperature during germination significantly affected the germination of seeds in soil. Under the temperature regime of 21 to 25 °C, soil fertility parameters were significantly higher. Pre-soaking of seeds had the highest stimulating effect on further germination of seeds in soil among the studied treatments. Pre-treatment of seeds with germination stimulants had generally a positive effect, increasing germination in soil.
Key words: biometric parameters, germination, pre-soaking, stimulators, temperature regimes, weight of 1000 seeds


The forest raw material base of Ukraine needs a long-term recovery, caused by current shortage of wood and in the long-term perspective, as well. One of the ways to solve this problem is to create plantations of Paulownia tomentosa (Thunb.) Steud., which are able to accumulate in a very short time a significant stock of wood, suitable for industrial use. Determination of the physical and mechanical properties was carried out on samples of standard sizes. It has been established that the density of paulownia wood, grown under the conditions of the Western Forest Steppe of Ukraine, ranges from 329–342 kg·m-3 (sapwood, heartwood) to 416 kg·m-3 (middle part between the sapwood and heartwood). Under the conditions when only air moisture influences the wood, the moisture content increases up to 12.9 %. Static bending strength, compressive strength parallel to grain, static hardness, modulus of elasticity of sapwood and heartwood parts of the trunk are characterized by minimum values, and the middle part (between the sapwood and heartwood) – by maximum ones. Therefore, in terms of appearance and texture, the wood has the most similarity with the wood of common ash; considering its density value, paulownia wood resembles the wood of Norway spruce and silver fir, but due to lower moisture absorption and the content of tannins, it is more resistant to decay than the mentioned species; the middle part according to some mechanical indicators is close to common pine wood, therefore, it can be widely used in building industry. Paulownia tomentosa wood is advisable to be used as a promising material for the production of firewood and wood pellets. The data we have obtained can be taken into account by specialists in the woodworking, furniture and agricultural industries when planning the creation of plantations and the use of its wood.
Key words: modulus of elasticity, moisture content, plantations, porosity, shrinkage, strength,
swelling.