Variety traits

Cold tolerance of sunflower

Helianthus annuus L.

The ability of sunflower seeds to germinate and the growth rate of seedlings under low-temperature conditions, ensuring uniform emergence during early spring sowing.

In the reference 8 varieties crop Sunflower, where this is mentioned in the description.

The cold tolerance of sunflower is determined by the ability of seeds to germinate at temperatures below the optimum. The trait is evaluated using laboratory methods by incubation in thermostats at a temperature of about 10°C, where germination energy and rate, as well as morphometric indices of the seedlings, are measured.

The biochemical assessment method is based on the accumulation of free proline in leaves after cooling, based on which a cold tolerance coefficient is calculated. Samples with a coefficient of 3.01 and above are considered highly cold-tolerant, 1.51–3.00 are moderately cold-tolerant, and 1.50 and below are low in cold tolerance.

For practical cultivation, the crop is capable of germinating at 4–5°C; however, to ensure uniform emergence, the optimum soil temperature at the sowing depth is considered to be between 8 and 14°C. Breeding for this trait allows plants to overcome the critical period of ontogeny faster, reducing the time to emergence.

General information about the subject — on the page Cold tolerance.

Sources7

Varieties of Sunflower mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.