Деякі особливості формування крони азиміни трилопатевої (Asimina triloba (L.) Dunal) за інтродукції у лісостепову зону України

Abstract

It was explained the meaning of introduction ( Asimina triloba (L.) Dunal ) in the forest - steppe zone of Ukraine and characterized some morphological features of the crops . In the subtropical zone , where there is a natural area of the species , tree crowns , which have brittle timber and fragile do not grow in the conditions of heavy snowfalls and glazed frost . The such untoward meteorological phenomenon take place in the forest - steppe zone of Ukraine annually and it causes separating of tree crowns during some winters. To prevent damage it was suggested one of possible ways of forming crown Asimina triloba. It will prevent splitting off the framework branches from the tree trunk. According to the recommendations of the scientists from Nikitsky Botanical Garden – National Research Centre, the forming of the main crop framework рослин is possible in two-three years after planting, extracting lower shoots, forming a tree with high of 80-90 cm and thin crown with 6-8 shoots. It was given some literary data about forming of the crown of Asimina triloba in the south of Crimea. It is worth taking account the argument of unfavourable meteorological phenomena, which are available in the moderate climate. The special approach is used to select the ways of forming the plant crown with brittle timber. The aim of research – to study morphological special features of Asimina triloba and to suggest the way of forming of the crop crown taking account the such unfavourable meteorological phenomena as heavy snowfalls and glazed frost, characterizing for the forest-steppe zone of Ukraine . The materials and the research method . The collection of the local seed crops of Asimina triloba in the age of 8 was used. The collection is situated in the research zone of Khorol Botanical garden and in the seedbed placing outside of its territory. The research methods are visible investigations, imaginary modeling. The results of research and their discussion . Choosing of forming crown of the introduction crop using old ways and working out new ways are essential stages of the growing species in the changed natural conditions. Besides , the ways of forming crown of the the introduction crop must be account morphological special features , bear fruit and unfavourable meteorological phenomena in the forest-steppe zone of Ukraine . During the investigations it was noted that skeleton branches of the first arrangement sprout forward to the trunk under the sharp ungle in the crops of Asimina triloba in the age of 6. To prevent splitting off the skeleton branches from the tree trunk we have aimed to form the fruit tree crown with brunches which can keep much snow and thick layer of ice not braking out. The decision is to form the skeleton branches because the branches of the second arrangement form from one side to the branches of the first arrangement. As a result, the branches of the first arrangement under much snow or ice keep their form, gently deforming and rolling. When snow melts, the skelet branches willrevert to their state having mechanical elasticity. So, the proposed method of forming fruit tree crown of Asimina triloba in the agricultural conditions of the forest-steppe zone of Ukraine prevents splitting off the skeleton branches from the tree trunk during heavy precipitations in the cold period of the year. This meethod is necessary for forming tree trunk of Asimina triloba. The method of forming crown is protected as a new technical decision as a patent on useful model. Conclusions High adapted potential of Asimina triloba, as it is proof to frost in the forest-steppe zone of Ukraine and forming tree crown by taking account the crop protection from mechanical damage in the conditions of heavy snowfalls and rainfalls are favourable for valuable using and spreading Asimina triloba as a fruit crop on the economic areas and farmer gardens of the region.