Improving propagation technology of Ligustrum L. planting material for greening urbanised areas

The relevance of the study is due to the need to improve the quality of planting material and expand the range of ornamental plants for landscaping urbanised areas. The aim of the study was to improve the technology of privet propagation, taking into account the biological characteristics and factors affecting the rooting process, such as the use of root formation stimulants and the choice of substrates. Comparison of rooting of green and lignified cuttings revealed different efficiency depending on the substrates and root formation stimulants used, in particular, Rizopon, Heteroauxin super and Grandis. The experiments showed that the most effective root stimulant was Rizopon, which increased the percentage of rooting of cuttings by 5-10% compared to the control. The highest rooting rates were observed in Ligustrum vulgare L. and its cultivars ‘Atrovirens’ and ‘Aurea’, reaching 96 %. The substrate based on peat and river sand (2:1) was the most optimal for most species, while for Ligustrum ibota ‘Musli’ the use of pure river sand was more effective. The results of propagation by lignified cuttings showed an order of magnitude higher percentage of rooting for most of the studied plants, in particular, L. vulgare L., and its cultivars, the percentage of rooting ranges from 86-96%, while rooting by green cuttings – from 85-90%. In the case of L. ovalifolium Hassk. These indicators were somewhat lower but satisfactory, lignified cuttings 75-92%, green cuttings 74-90%. L. ibota ‘Musli’ and Ligustrum japonicum ‘Green Century’ have mediocre rooting results both with lignified and green cuttings, L. ibota ‘Musli’ when propagated by lignified cuttings had a result in the range of 12-14%, and lignified cuttings 66-68%. L. japonicum ‘Green Century’ had a higher percentage of rooting when propagated by lignified cuttings 47-62%. The results of the study can be used to increase the efficiency of privet propagation and improve the technology of growing high-quality planting material resistant to the conditions of the urbanised environment. These studies serve as an informational scientific basis for improving the systems of ornamental seedling production