Удосконалення агротехніки вирощування садивного матеріалу горіха чорного (Juglans nigra L.) у лісовому розсаднику Державного підприємства «Лисянське лісове господарство»

Abstract

Anthropogenic impact on the environment leads in most cases to forest systems degradation; therefore there is a need for the forest science development towards a balance finding between forest’s ecological functions and economic effect from stands. Introduced species are of great importance in this respect, especially if they are dominated by native tree species. Feasibility of diverse use of black walnut fruits and wood, the urgency of searching for tree species, which are resistant to negative impacts associated with climate change, the issue of increasing pests and diseases resistance encourages scientists to an in-depth study of the questions on the possibilities of black walnut cultivation in the Right Bank Forest-Steppe of Ukraine. Taking into account the previous experience of black walnut growing in this region and its prospects, we have decided to study more thoroughly the first stage of high-yielding stands restoration, which involves forest stands development. The study included several stages, in particular: studying of black walnut growing experience, seeds quality inspection, sites selection according to forestry scientists recommendations for this species conditions, test plots establishment using plant growth regulators with the definition of the most effective ones and identification of optimal doses of their application. To study the influence of plant growth regulators on the growth and development of black walnut plants we used preparations of N-oxide pyridine derivatives and their compositions with the biological preparation of Ecostim-1. Bleached were the seeds of black nuts, which had a tight germ of milk-white or cream color. The quality of samples was 99 %. The best results in the first year of autumn growth were obtained using growth regulators of group 1. In the group 1 percent of liveliness varied from 73 % to 93 % in June and from 77 % to 90 % in October. On the control site the survivability is 69 %. Comparing the height of black walnut tree seedlings, determined in spring and autumn, it should be emphasized that the increase of seedlings height of black walnut was proportional – the highest plants of the spring period remained the same in the autumn period. In autumn the seedlings grown using growth regulators D5S, D11S, D13S, D16S, D20S, D21S, DGK6, DGUR had the height of more than 90 cm. In the control area the height of the black walnut plants in the spring period was 20 cm, and in the autumn it was 76 cm. Having determined the average diameter of the plants at the height of the root collar, we obtained the best results using D5S, but there are no significant fluctuations on this indicator.