Yoraku-Tama
ActiveHydrangea L. · Hydrangea
Information regarding the breeder received in the contribution to CPVO :Tsunetani
Variety traits
Frost hardiness is the genetically determined ability of a plant to withstand exposure to sub-zero temperatures without tissue damage. This indicator reflects the critical temperature threshold beyond which the plant dies.
Mentioned in descriptions 11 978 varieties reference book.
Frost hardiness represents the ability of a plant organism to resist the impact of low sub-zero temperatures. It determines the critical threshold above which plant tissues undergo irreversible damage or death. Unlike overall winter hardiness, which also accounts for damping-off and the effects of thaws, frost hardiness focuses specifically on the cellular response to cold exposure.
This trait is genetically determined; however, its expression depends on the physiological state of the plant and the dynamics of external conditions. Frost hardiness is not a constant value: it increases during the period of deep winter dormancy and gradually decreases towards spring, as the plant loses its ability to resist cold due to dehardening.
The evaluation of frost hardiness during variety testing is conducted through laboratory freezing in controlled conditions or through long-term field observations of crop survival. For variety comparison, scoring scales, percentage of survival, or the determination of minimum permissible temperatures in degrees Celsius are used. Maximum realization of the innate genetic potential for frost hardiness is ensured by optimal sowing dates and adequate phosphorus-potassium fertilization in the autumn.
Selection based on the description text, not official resistance ratings: such data is not available in registers. Mention indicates that the trait is discussed in the variety's sources; see the variety's profile for details on what is specifically stated.
Hydrangea L. · Hydrangea
Information regarding the breeder received in the contribution to CPVO :Tsunetani
Lilium L. · Lily
Hydrangea macrophylla (Thunb.) Ser. · Bigleaf hydrangea
Information regarding the breeder received in the contribution to CPVO :Rampp
Lilium L. · Lily
Hydrangea serrata (Thunb.) Ser. var. serrata · Tea-of-heaven
No information of breeder available for this variety
Rosa L. · Rose
Lilium longiflorum Thunb. · Easter lily
Lilium L. · Lily
Lilium L. · Lily
Vitis vinifera L. · Common grape vine
Tulipa L. · Tulip
Vitis vinifera L. · Common grape vine
Malus domestica (Suckow) Borkh. · Apple
Hydrangea macrophylla (Thunb.) Ser. · Bigleaf hydrangea
No information of breeder available for this variety
Allium porrum L. · Leek
Semenarna Ljubljana, SI
Prunus dulcis (Mill.) D. A. Webb · Almond
Rosa L. · Rose
Pyrus communis L. · European pear
Vitis berlandieri Planch. x Vitis riparia Michx.
x Cuprocyparis leylandii (A. B. Jacks. & Dallim.) Farjon · Leyland cypress
Rosa L. · Rose
Tulipa L. · Tulip
Vitis vinifera L. · Common grape vine
Hydrangea paniculata Siebold · Panicled hydrangea
Information regarding the breeder received in the contribution to CPVO :Rehder