A complex adaptive trait of sunflower that determines yield stability under moisture deficit due to morphophysiological mechanisms and biochemical regulation of metabolism.
In the reference
75
varieties
crop Sunflower,
where this is mentioned in the description.
The evaluation of sunflower tolerance is based on biochemical markers, such as the accumulation of free proline, where an index of 4.1 and above indicates high tolerance. Also taken into account are the ability of roots to penetrate deep soil horizons, the water-holding capacity of leaves due to cuticular waxes, and the preservation of cell membrane integrity during dehydration.
From an agronomic perspective, drought tolerance is expressed by a higher threshold for pollen sterilization during high temperatures at the flowering stage and the ability to rapidly recover assimilation after stress. The critical periods for the crop are flowering and seed filling, where moisture deficiency can reduce yield by half, making it effective to maintain a plant density of 45–55 thousand plants per hectare in arid zones.
General information about the subject — on the page
Drought tolerance.
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.