2018 ASHS Annual Conference

Specialty cut sunflower (Helianthus annuus L.) cultivars response to pinching depends on time of planting and cultivar characteristics. Experiments evaluated five non-branching sunflower cultivars 'Pro Cut Gold’, ‘Sunbright Supreme’, ‘Sunrich Lemon’, ’Superior Gold’ and ‘Vincent’s Choice’ pinched at nodes 0 (non-pinched), 1, 2, 3, or 4. Stem length, stem diameter, flower diameter, and disk diameter were measured at harvest along with days-to-harvest, number of stems and number of marketable stems. Pinched sunflowers produced significantly more stems than the non-pinched sunflowers, but also resulting in decreased stem length, stem diameter, flower diameter and disk diameter. Conversely, days-to-harvest increased with pinching. Spring planting increased the number of marketable sunflower stems pinched at nodes 1, 2, and 3, but Fall planting produced a similar number of marketable stems to the non-pinched treatment. The more vigorous cultivar ‘Superior Gold’ tended to performed better than less vigorous cultivar such as ‘Sunrich Lemon’. These initial experiments indicate that pinching specialty cut sunflowers may not be an effective method for increasing sunflower production in Texas.