Mycorrhiza Formation in Pinus Sylvestris and Picea Obovata Seedlings in Forest Nurseries in Kazakhstan

This work presents research materials, the purpose of which is to grow seedlings of coniferous trees in the open field using artificial substrates of mycorrhizal macromycetes in forest nurseries of Central, North and Northeast Kazakhstan. The success of mycorrhiza formation in seedlings Pinus sylvestris and Picea obovata from forest nurseries of Akmola and Karaganda regions, and the survival rate of seedlings from forest nurseries of Akmola, Karaganda and Pavlodar regions of Kazakhstan are analysed. In the future, we want to expand the range of studied species and compare artificially mycorrhized seedlings with naturally mycorrhized species from natural forests. If we compare the survival rate of seedlings in nurseries, the highest in P. sylvestris seedlings in Shaldai is about 78%, low in Novodolenskoe, about 27%, and for P. obovata, on average, 66%. In the future, we want to expand the range of studied species and compare artificially mycorrhized seedlings with naturally mycorrhized species from natural forests.

FIRST RECORD OF CINARA (CINARA) CEDRI CEDRI MIMEUR (HEMIPTERA APHIDIDAE) IN BULGARIA

In 2017, damages caused by aphids were observed for the first time on Cedar trees in Bulgaria. In 2020, apterae specimens of Cinara (Cinara) cedri cedri were collected and identified on Cedrus atlantica and C. deodara in seven localities both on young trees in forest nurseries and on old trees in plantations or in green urban systems. The pest appears to be a serious threat to the health status and decorative characteristics of Cedar trees. In case of high population density, the needles are covered with large honeydew secretions and sooty mold.

The complex of machines for low-cost artificial reforestation in the taiga zone

Problems of mechanization of artificial reforestation in the taiga zone are increasing the productivity of manual labour and reducing the costs of subsequent young stand treatment (early tending and early pre-commercial thinning). Petrozavodsk State University has developed the complex of machines and technologies capable to solve these problems. This complex includes: seeder, root-cutter, dynamic hole-maker and mechanical mounder. Seeder and root-cutter are intended for growing enlarged seedlings with an open root system in forest nurseries. Seeder provides mechanization of sowing seeds. Root-cutter is used for pruning the root systems of seedlings during cultivation. Dynamic hole-maker provides strip soil clearing, surface tillage and preparation of holes for manual planting of seedlings. The hole-maker is also capable to make soil scarification and sowing forest seeds. Mechanical mounder provides strip clearing in the forest plot and creation of humus mounds with mineral soil cover for manual planting of seedlings. Basic technological parameters of the complex of machines have been also substantiated at the Petrozavodsk State University.

Effectiveness of stimulating treatment cuttings of privet common (Ligustrum vulgare L.) with biologically active preparations

The effectiveness of the use biologically active substances in the rooting of cuttings privet common (Ligustrum vulgare L.) in its introduction in the region of Nizhny Novgorod was studied. The processes of callus adventitious root formation were studied. The research target was an arboretum collection of common privet in Nizhny Novgorod State Agricultural Academy with geographical coordinates 56°19′43” N, 44°00′O7” E and an altitude of 141 m above sea level. Tested nine industrially produced biologically active preparations widely used in tree and forest nurseries to increase the efficiency of rooting cuttings. The positive effect of cutting treatment with biologically active preparations was confirmed. A significant intensity of callus formation was recorded in the variants with profistim (98.50±1.05%) and extrasol (96.50±0.76%). A noticeable increase in the number of adnexal roots was caused by the use of the drugs heteroauxin (24.55±1.08 pcs.) and ferovit (22.00±1.38 pcs.). The best results for the total length of adventive roots were obtained after the use of heteroauxin (266.92±16.71 cm) and ecofus (272.22±14.42 cm). The effectiveness of bioactive drugs in stimulating regeneration processes on privet cuttings, increasing in the intensity of callus formation and the rate of linear growth of adventitious roots has been proven.

Economic assessment of application of new reforestation technologies in conditions of climate change in the forest-steppe zone of Russia

The development and application of new reforestation technologies remain relevant due to climate change. The main technology of forest sowing in Russia does not provide effective reforestation. Innovative technologies of reforestation based on seedlings with a closed root system make it possible to increase the livelihood of plants and accelerate reforestation processes. Using the method of determining costs, a comparative economic analysis of the technologies for growing oak seedlings with an open and closed root system in the forest-steppe regions of Russia was carried out. It was found that the technology of growing seedlings with a closed root system is less labor-consuming and provides a high level of income for investments. The innovative technology of growing seedlings with a closed root system in greenhouses is more competitive and its use allows to generate income from one hectare of area 50 times more than when growing seedlings in forest nurseries by increasing the number of seedling rotation. A comparative economic assessment of two oak seedling projects under forest-steppe conditions suggests the feasibility of moving to innovative reforestation technologies. In the current climate change conditions, a serious correction of approaches to reforestation in the forest-steppe zones of Russia is necessary.

THE EFFECTIVENESS OF NATURAL GROWTH STIMULANTS IN THE CULTIVATION OF SEEDLINGS OF PICEA OBOVATA LEDEB.

Picea obovata Ledeb. is a slow-growing in the early stages of growth type of coniferous trees. The use of growth stimulants in the cultivation of spruce seedlings can accelerate the production of standard planting material. The paper presents the results of research of plant growth regulators influence on spruce seedlings within three years of cultivation in forest nursery conditions. Before sowing seeds of spruce soak in solutions of biological-active preparations Verva and Verva-spruce, obtaining from Abies and Picea wood greenery extracts. The plants growth regulator Verva from Abies needles (operating substance – triterpenic acids) is applied in plant growing at cultivation agricultural and commercial crops. Operating substance of a preparation Verva-spruce used for protection of agricultural plants from diseases, are phenolic compounds of Picea wood greenery possessing fungicidal and insecticidal activity. It is established that spruce seedlings processed before sowing by bio-preparation had higher parameters of growth (seedling height, diameter of seedling tree at root neck) in comparison with control plants within three years of cultivation in conditions of forest nursery. Three-year spruce seedlings which have been grown up with use of growth stimulators Verva and Verva-spruce exceeded control on 20–30% on height and on 19–20% on seedling tree thickness. Bio-preparations Verva and Verva-spruce can be recommended for application in forest nurseries as effective growth stimulators at cultivation of Siberian spruce landing material.

Experimental Examination of Vegetative Propagation Methods of Nothofagus antarctica (G. Forst.) Oerst. for Restoration of Fire-Damaged Forest in Torres del Paine National Park, Chile

Nothofagus antarctica (Antarctic beech) is one of the main woody plants in the temperate deciduous forests and anti-boreal forests of the southern hemisphere. Since colonization of the Andean-Patagonian region by European settlers, however, stands of this species have been severely affected by fires caused by human activities, considerably reducing their area. To restore these forests to their area occupied before the fires, it is necessary to use artificial regeneration, relying on production of transplants in forest nurseries. Due to the low capacity for seed propagation, we focus on possibilities of producing seedlings by vegetative propagation. In a trial, we collected cuttings during three sets of dates, and attempted to root them using three combinations of substrate and ten combinations of stimulators. Using the most favorable combination of collection period, substrate and stimulator tested resulted in rooting of 23% of the cuttings, which exceeds the documented germination rates for this species.

Development of organomineral compost for growing forest planting material

The organomineral compost compositions, which provide increased biometric indicators of seedlings of forest plants, are described. Compost is obtained on the basis of the secondary resources of forest and agricultural production. The compost readiness indicator, depending on the composition and composting time, is proposed. The influence of the polymer structure-forming agent of the soil on the compost quality is shown. The influence of compost composition variations on the morphometric parameters of seedlings is studied. The recommended ratios of ingredients in organomineral compost for growing planting material in forest nurseries are given.

Compost and PGP-Based Biostimulant as Alternative to Peat and NPK Fertilization in Chestnut (Castanea Sativa Mill.) Nursery Production

In forest nurseries, intensive use of non-renewable substrates such as peat and high application rates of chemical synthesis fertilizers lead to environmental problems and high susceptibility to biotic and abiotic stresses. This work aims to seek more sustainable crop management to help mitigate these problems, combining the substitution of peat by compost and the use of growth-promoting microorganisms (PGPs) as a fertilization tool. For this purpose, a trial was carried out to test the effectiveness of an agricultural waste compost and a biostimulant based on PGP microorganisms in the production of Castanea sativa plants in a forest nursery. This trial assessed the growth of plants, with both inputs separately and combined, and then studied the tolerance of chestnut seedlings to water deficit. The results showed that partial substitution of peat by compost is possible, but not complete, as the high levels of conductivity and pH generated by a high proportion of compost negatively affected plant growth. It was also noted that the application of the biostimulant enables the complete substitution of mineral fertilization. Moreover, at the end of the nursery phase, chestnut seedlings treated with the biostimulant showed the same or even better quality than chestnut seedlings obtained with conventional fertilization, also resulting in greater resistance to water deficit, based on the increase in root volume and the improvement of the physiological status. Changes observed in both quantity and composition of microbiota associated with chestnut rhizosphere after inoculation with PGPs were related to the improvement observed. In relation to water deficit resistance, a positive synergy was also observed with the combination of both inputs, since plants with full substitution of peat by compost combined with PGP-based fertilization showed the greatest drought resistance.