Scientific Journal of KubSAU

Peach fruit is much demanded worldwide. The success of its cultivation depends on the optimal plant placement of all the huge biodiversity considering the cultivar demands. The northern boundary of the peach cultivation passes through the Kiev-Kharkov-Rostov-on-Don, Maikop, Nalchik, Grozny, Astrakhan (Witkowski, 2003). However, because of extreme temperatures there are almost no suitable areas for Peach crop cultivation in these borderlands, in the Krasnodar and the Stavropol regions. From the other hand, extreme temperatures for peach cultivation in the humid Russian subtropics were not observed. Spring frosts till -5 ° C were observed in 2004, 2014. However, the cultivar productivity in the region influenced by the duration of low temperatures (7,2 ° C and below) that were observed from December to March. The amount of low temperatures for each cultivar was established using the highest coefficient of yield determination, depending on the temperature, amount of precipitation and the "cooling unit." The yield of peach cultivars is closely linked with the abovementioned agro-climatic conditions during the flowering period. Paired correlation coefficients of yield with precipitation and with temperatures (for most cultivars) were negative, and since they are unregulated value, the flowering phase is crucial for peach culture in the Russian subtropics

The close dependence of peach yield on the weather factors in the humid subtropical zone has been established. The observed climate changes in recent years (2000–2018) significantly affected the production potential of peach cultivars. An increase in temperature and precipitation in February-March negatively affected morphogenesis of the flower buds, which reduces the yield of most cultivars. The significant variability of precipitation (the main constraint of peach production) in the winter and early spring, the low weather predictability, characterize the onset of flowering by the “critical” phase. Weather conditions were changed during ripening. In July and August, the amount of precipitation decreased, the temperature increased, which led to moisture deficit and fruits quality deterioration. Local climate change in humid subtropics actualizes the development of adaptive cultivars with a high ecological and adaptive plasticity. Selected clones of the Red Heaven, Krasnaya Zarya and Larisa are the most adapted to the local conditions and can be successfully used in the low mountain area of the subtropics

The main criteria in assessing the adaptive capacity of Actinidia deliciosa (kiwi), cultivated in Russian subtropics were yield of the introduced cultivars, as well as ecological (stability and periodicity of fruiting) and biological indicators (resistance and periodicity of fruiting). The studied nature of the way Actinidia cultivars react to the constantly changing weather conditions during the period from 1998 to 2011 will help to optimize the placement of the crop in subtropical zone, and use natural resources for its unique climatic properties of Russian territory in a sustainable way

The influence of climate factors on adaptiveness of Actinidia deliciosa strange cultivars is ascertained in damp subtropics of Russia. The basic limiting factor of its cultivation is precipitation quantity during flowering phase and fetal maturity

Such agrochemical and agrophysical properties of soils as base saturation degree, number of fine sand and dust fractions, as well as of physical clay limit the tea crop productivity in the Maykop region and in damp subtropics of Russia. Multiple regression models of their close influence on tea plantations productivity have been obtained

Increasing of tea production in the foothills of Adygea should be based on potential soil properties suitable for tea plant. The goal was achieved using modern methods of soil evaluation of tea plantations. The evaluation criteria were the following agrochemical and agro indicators: soil acidity (pH KCl); hydrolytic acidity; the sum of exchangeable bases; bases saturation; granulometric composition. It was found that the soil under tea plantation in Adygeya classifies as brown forest poorly unsaturated with the level of potential fertility rated as satisfactory (bonitet rating 40-60). However, the low supply of nutrients in the layer 0-40 cm: phosphorus (19,04 ± 2,42 mg / 100 g soil), potassium (17,70 ± 1,60 mg / 100 g soil) and a sufficiently high degree of saturation of soil bases in the layer of 50- 100 cm (67,10 ± 11,67%) in combination with a soil moisture deficit determine their low productivity of 16,0 ± 5,0 kg / ha, whereas their potential productivity of 30-50 t / ha. The development of scientifically grounded, targeted ameliorative and agro-technical measures (irrigation, nutrition systems using physiologically acidic forms of nitrogen and potash fertilizers that reduce the degree of saturation of the soil bases) will help to increase the effective soil fertility and allow the tea plants reach its biological potential and achieve predicted productivity in Adygea region