Variety traits
Cold tolerance is a biological characteristic of a variety that determines its ability to develop and maintain productivity under prolonged exposure to low positive temperatures (from +1 to +10 °C).
Mentioned in descriptions 2 844 varieties reference book.
Cold tolerance represents the ability of an organism to maintain normal metabolism, protoplasm structure, and enzymatic activity under conditions where thermophilic crops begin to slow growth, yellow, and lose turgor. Unlike winter hardiness, this indicator does not imply the tolerance of sub-zero temperatures and freezing of tissues. In practice, a cold-tolerant variety allows for early sowing in unheated soil, reduces the risk of seedling death during spring cold snaps, contributes to the efficient use of winter moisture, and accelerates development, which often leads to earlier maturity.
Field and laboratory evaluation methods are used during variety testing. The field methodology includes phenological observations of growth rates during early sowing, visual assessment of survival after temperature stress, and structural analysis of the impact of conditions on yield components. In laboratory settings, a 'cold test' is used for seed germination in incubators at reduced temperatures followed by further growth, as well as biochemical analysis, such as determining the level of free proline in leaves.
Cold tolerance is expressed through a coefficient calculated as the ratio of performance in stress conditions to control conditions, or through percentage values of germination. Based on these data, varieties are divided into groups by resistance level. An important indicator is the temperature minimum at which crop growth ceases, which is about +4 °C for most plants and up to +10 °C for maize. Variety selection requires consideration of the biological characteristics of the crop, as this trait is critical for thermophilic plants at the early development stage.
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.
Zea mays L. subsp. mays (Maize Group) · Maize
KWS SAAT SE & CO.KGAA
Petroselinum crispum (Mill.) Nyman ex A. W. Hill · Parsley
SEMINIS VEGETABLE SEEDS, NL
Zea mays L. · Maize
SEMENCES NICKERSON
Zea mays L. · Maize
Pierre CAROLO
Allium porrum L. · Leek
WAGNER| Julius Wagner GmbH
Lactuca sativa L. · Lettuce
Semenarna Ljubljana, SI
Lactuca sativa L. · Lettuce
Seminis Vegetable Seeds
Zea mays L. · Maize
Syngenta Crop Protection,CH
Zea mays L. · Maize
Pinter Zoltan / Gyulavari Oszkar / Szel Sandor / Kalman Laszlo / Devenyi Karolyne
Brassica oleracea L. (Savoy Cabbage Group) · Savoy cabbage
Sakata Seed Corporation
Brassica napus var. napus · Rapeseed
PIONEER OVERSEAS CORPORATION
Daucus carota L. · Carrot
MORAVOSEED
Lactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
Helianthus annuus L. · Sunflower
ISEA S.P.A.
Zea mays L. · Maize
ROBERT TAUCHER
Zea mays L. · Maize
Melnyk Taras Vitaliiovych, Moskalenko Volodymyr Fedorovych, Melnyk Vitalii IAkovych,
Helianthus annuus L. · Sunflower
MIRASOL SEED SLU
Pisum sativum L. · Pea
Agri-Obtentions S.A., Institut National de Recherche pour l'Agriculture l'Alimentation et l'Environnement (INRAE)
Asparagus officinalis L. · Asparagus
UNIVERSITY OF GUELPH
Medicago sativa L. · Alfalfa
Ferri Luigi Sementi Srl (IT)
Solanum lycopersicum L. · Tomato
SEMO a.s
Citrullus lanatus (Thunb.) Matsum. & Nakai · Watermelon
MAURIZIO BACCHI
Citrullus lanatus (Thunb.) Matsum. & Nakai · Watermelon
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Brassica oleracea L. (Broccoli Group) · Broccoli
Sakata Seed Corporation, JP