The article presents results of the study of new apple varieties and hybrids for the main components of winter hardiness by applying the method of artificial freezing. The varieties Verbnoye, Witos, Imant, Syabryna, Yubilyar, the hybrids 85-14/95, 86-54/133, 86-56/29, 86-56/44 and 86-56/78 were selected for complex of indicators of high winter hardiness. These accessions are suitable initial material for further breeding. To the majority of allocated variety samples on two components of winter hardiness stability to sharp temperature drops during a thawing weather is characteristic, insufficient frost resistance of wood, a core and vascular-conducting bundle is noted at sharp decrease in temperature up to-40 deg C. In natural conditions at (-29.3 deg C) in January 2003 and at (-29.0 deg C) in January 2006 practically all investigated variety samples have shown high stability to cold stresses. They are capable to transmit in the tempered condition sharp temperature drop up to (-25 deg C) during thawing weather (+2 deg C). Thus damages of fabrics of annual branches and vegetative buds do not exceed 2,0 points. Allocated variety samples with high genetic potential stability on the main components of winter hardiness are the valuable selection material at selection of parental pairs for creation of varieties with the assigned parameters and for the state strain testing

As a result of conducted research on influence of temperature on growth of black leg and potato soft rot agents in vitro it is determined, that the maximum augmentation of biomass Pectobacterium carotovorum subsp. atrosepticum takes place at 24 deg C, optimum conditions for Pectobacterium carotovorum subsp. carotovorum growth develop at temperature 27 - 30 deg C. At temperatures from 16 up to 35 deg C Pectobacterium carotovorum subsp. carotovorum is characterized by more intensive cell division, than Pectobacterium carotovorum subsp. atrosepticum. Development of soft rot on potato tubers inoculated with Pectobacterium carotovorum increases with growth of temperature in a range 5-27 deg C. Maximum soft rot development in potato tubers was reached at 27 deg C. The bacteria Pectobacterium carotovorum subsp. carotovorum tend to cause rotting of plant tissues at high temperatures. Only in a narrow temperature range close to 20 deg C both bacteria agents of black leg and soft rot develop at equal rates

Research results of the influence of interstocks on fruit yield of varieties Antej and Telisaare apple trees for age-specific periods, and the study results of specific indices of yield load depending on the interstock vigour are concerned. The semi-dwarf interstocks 3-3-35, 3-6-47, 3-17-27 and the dwarf interstocks B 9, N 134, P 22 have been studied. The cropping for both varieties Antej and Telisaare was higher on the interstock 3-3-35. For the varieties Antej and Telisaare on the dwarf interstocks specific fruit load of the trunk cross sectional area, crown projection area and leave surface area was higher by 1,5 times than for the same varieties on the semi-dwarf interstocks. When comparising the same variants of varieties Antej and Telisaare on specific fruit load results of crown projection area (per unit area) it is clear that in control variant this index at variety Antej was more in 1,4 times, and variants with interstocks 3-3-35 and 3-17-27 - in 1,6-1,9 times more than in analogous variants at variety Telisaare. Specific indices of fruit load of the apple trees of variety Antej on variants were higher by 2 times in comparison with variety Telisaare

The data of research carried out in 2002-2006 are presented. Optimal constructions for commercial orchards on the dwarf rootstock 62-396 and the semi-dwarf rootstock 54-118 combined with varieties of various vigor were studied. The experimental orchard was established with 2-year-old saplings in 1990. Trunk cross sectional area (TCSA) for the apple varieties Antej and Telisaare on various dwarf rootstocks with various crown training systems was lower for closer spacing and higher planting density. Higher increase in TCSA was noted for less dense plantations, namely, for plantation with in-row spacing being 2.5-3.0 m (163.2 – 191.2 square cm for 54-118 rootstock with plantiung density 833 and 1000 tree/ha; 117.3 – 153.4 square cm for 62-396 rootstock). Yield (kg per tree) of the apple varieties Antej and Telisaare on the studied rootstocks for all variants of crown forming systems was higher for wider spacing, however, productivity (in t per ha) raised with the increase in planting density (trees per ha). In 2002-2006 the highest yield has been received at variety Antej on both rootstocks at planting scheme 4x1.5 m – 38.5-40.7 t/ha per square unit. The least average yield has been received at variety Telisaare on rootstocks 54-118 and 62-396 – 17.4-19.3 t/ha per square unit

The 4-year research data on the influence of interstocks on fruit-bearing and fruit market qualities of the apple varieties Antej and Telisaare are presented. The semi-dwarf interstocks 3-3-35, 3-6-47, 3-17-27 and the dwarf interstocks В 9, N 134, P 22 were studied. The cropping was better on the interstock 3-3-35 for Antej and also on the interstocks 3-3-35 and N 134 for Telisaare. During the research period Antej and Telisaare fruit have got mean fruit weight on 10-l8% higher on semi-dwarf interstocks than on the dwarf ones, whereas the maximum fruit weight was received on the trees grown on 3-3-35 interstocks, e.g. 143 and 124 g, respectively. Higher output of commercial fruit for the variety Antej occurred on the interstocks 3-3-35 and amounted to 83%. The variety Telisaare had the same output of commercial fruit for all interstocks and amounted to 68%. The variety Antej had the greater output of extra-class fruit than the variety Telisaare

Mutability of apple rootstocks (54-118, 62-396 and PB-4) grown in vitro and in vivo conditions was evaluated. Anaphase method of genetic stability study was applied. It was stated that studied rootstocks do not display genetic variability detected by the given method. It corresponds to literature data about high genetic stability of apple tissue, including in vitro. It has been supposed that set of factors of introduction and maintenance in culture in vitro will render mutagen effect on studied rootstocks of apple-tree. Vegetative hormones of auxin, cytokinine and gibberellin group were in structure of nutrient medium for propagation. It is known, that phytoharmones influencing on process of cell propagation of plants (such as auxine and and cytokinine) can be considered as mutagen agents. However carried out research have not allowed to reveal increase in mutability of studied rootstocks of an apple-tree in conditions in vitro in comparison with the rootstocks cultivated by traditional methods (in vivo). For cells in a stage of anaphase rootstock PB-4, cells of the rootstock 54-118 and cells 62-396 which have been grown up in conditions in vivo, it was not possible to find out any cell with breach of anaphase of cellular division. Anaphases of cellular division occur normally, without formation of abberate structures. Similar results have been received for the studied stocks which have been grown up in conditions in vitro

Among vegetable cultures cultivated in Belarus the onion napiform are included into number of five basic vegetable cultures. Its biological features and ways of cultivation allow to receive the fresh production keeping high flavouring and commodity qualities within all year. The requirement for onions on the scientifically-proved norms for the republic population makes 10 kg on 1 inhabitant in year, including 7 kg of bulb onion, 2 kg of green onions and 1 kg of garlic. By results of two-year-old research on medium-loamy soils in onion crops on onion set entering into quality pre-emergence herbicide of 33% of concentrate of Stomps emulsion (pendimetalin) of firm BASF, Germany in a dose of 4,0-4,5 l/hectares is recommended. For elimination of arising errors of chemical protection against weeds at application of pre-emergence soil herbicides it is the most rational to use desiccant Reglon super, (diquat, 150 g/l) of firms Singenta Limited, Great Britain in a dose of 2,0 l/hectares. In onion crops on set in early phases of its development herbicides Piramin turbo and Ramrod can be used. The greatest effect is received at application of their tank mixes

Four-year data on the photosynthetic active radiations entry to the apple crowns in orchard constructions of various intensity are presented. The more dense constructions were the stronger impact they had on the light regime. All cultivar-rootstock combinations in study had significantly lower photosynthetic active radiation in variants with dense plantation. In-row spacing as well as inter-row spacing factors were significant, however, in-row density made higher impact on the light regime. The intensity of photosynthetic active radiation entry significantly decreased from the periphery to the center of apple crowns. For dense spacing variants, in the central part of crowns on the height of 1.5 m from the ground level the light regime was not sufficient for lying generative buds in the case of young trees, and the regime of negative photosynthesis established when trees got older. Crowns of the variety Pobeditel on interstock of dwarfish rootstock N 134 at the scheme of placement of trees 4 х 1 m differed especially by low values of photosynthetic active radiation (PAR). At formation of freely growing plane crown this variety-rootstock combination is not-suitable for planting gardens of high density, packing up to 833 tree/ha is admissible. The variety of apple-tree Wealthy because of its high-quality features habitus crown and branching is suitable for planting of dense plants in a greater degree. At formation of freely growing plane crown packing up to 1250tree/ha is admissible

Major goal in the selection for scab-resistance is early diagnostics of resistance of breeding material, which is performed by mandatory application of artificial media. The article concerns the results of evaluation on scab-resistance apple seedlings in the artificial infection media. At research carrying out it is established the low germination of seeds received as a result of crossings of varieties and hybrids of interspecific origin, because of the incomplete fertilization shown at incompatibility of parental forms, and also low temperature of air during flowering. Efficiency of selection on stability to scab at early stages of development seedlings on an artificial infectious background depends on inoculum type. For creation of an artificial background at estimation of selection material of an apple-tree on stability to scab the best result is received in case of use of fresh leaves and preserved. The greatest output of steady seedlings is received in hybrid families in which both parental forms are sources of immunity to scab: Imant, Pospekh, Darunak, Belorusskoe sladkoe, Start, 86-54/133, 86-56/121, 86-54/137, 86-55/53 and 88-24/6

The results of the study on 13 early ripening strawberry varieties carried out in 2004-2006 are presented. The most promising varieties for certain features were selected. High yielding and large-fruited strawberry varieties Kokinskaya zarya, Kama, Honeoye are chosen as initial material for selection of strawberry. Because of its biochemical indices variety Gera can be used as initial breeding material for selection of early ripening strawberry varieties with improved biochemical berries composition