The research programme is focused on creation of new genotypes with higher resistance against diseases and on increasing the stability of such resistance. New donors of the resistance against diseases are searched. With a chosen set of cultivars and novel-breeding the resistance stability to local pathotypes Venturia inaequalis linked to various climatic factors and ways of fruit growing is tested. Another objective is to create new genotypes of apples by the means of combination crossing, which will include two different systems of resistance to scab or will combine this resistance with the resistance to powdery mildew. Within the international research project Eureka breeding material of apples is selected concerning improvement of the quality of fruits, resistance to diseases and occurrence of some other important features. Great emphasis is placed on assessment of good fruit storability. Prospective genotypes are chosen with the help of modern selection methods. The main objective of selection concerning pears is resistance to fire-blight.
At different stages of breeding process broad breeding material of apples and pears is selected. Recently around 16 thousand original hybrids have been evaluated at the fruitage phase. The work is focused on selection of prospective novel breeding in hybrid orchards and analyses of genotypes in the station experiments.
Recently more than 1200 plum hybrids planted on permanent sites have been evaluated. The hybrids affected by plum pox were individually removed from the planting. Most of these hybrids set in fertility in 1999 and 2000. 750 hybrids were evaluated for the fruit traits. Out of this number 65 genotypes were selected for further evaluation on the level of station tests and operation experiments. Most of them proved very good quality of fruit. This material developed from crossing of cultivars resistant or tolerant to viral plum pox. The harvest time of the selected genotypes stretched between July 22nd and October 25th, the weight of the fruits ranged from 25 to 50 g, the value of refractionometric dry residue ranges from 11 to 23. The selected genotypes are screened for plum fox resistance. The target of this research is to choose the best donors of resistance against this disease and to include them to the new phase of combination crossing.
The research on the field of sweet cherry and apricot is focused on the issues of heredity of economically important properties and on creation of new genotypes with higher resistance to diseases and frost. One of the objectives is also development of self-pollinating varieties. The possibility of selection of prospective rootstock for sweet cherries based on evaluation is examined and selection of the offspring developed by crossing between cherry and the interspecific hybrid Ceropadus, which is noted for considerable resistance to diseases. The target is to develop clones suitable for air layering that would positively affect growth and fertility of the grafted cultivars.
At different stages of breeding process broad breeding material of sweet cherries and apricots is selected. Selection of cherry trees is focused on size of fruit, resistance to cracking, growth vigour suitable for low shapes and fruit quality, especially in early and late ripening hybrids. In apricots the main objective of the selection is the suitability of the genotypes for the marginal regions of growing this sort of fruit. The works are focused on selection of novel breeding in hybrid orchards and on evaluation of station experiments. About 5.000 hybrids have been evaluated at in the fruitage stage these days.
The research in this field is focused on prerequisites for establishment of modern intensive planting of plums in the Czech Republic. Emphasis is also placed on creation of genotypes with better resistance or toleration to viral plum pox and selection of the most suitable cultivars, clones for domestic grower conditions. The occurrence of plum pox is monitored. The measures for minimizing the risks of spreading plum pox are searched. The subject of the research is also procedure of planting low shapes in plums. The previous experience has brought some general knowledge. Dense planting demands very high and modern technological level. It also demands higher level of protection mainly against pests, better care when tilling the soil, and above all better knowledge and skills of the grower. The right choice of the variety for these ways of planting is also an important factor. The economy of this type of plantings is monitored too.
Complex research of low shapes of sweet cherries is carried out. Selected varieties and rootstock is evaluated in several different shaping and clipping systems. The influence of foliar application of calcium on cracking of cherries is observed. Based on this research suitable cultivars and rootstock will be selected for dense planting of low shapes of sweet cherry trees.