Pinching and Spacing Effects on Cut Sunflower (Helianthus annuus) Production in East Texas

Author

Rebecca B. Burnett, Stephen F Austin State UniversityFollow

Date of Award

Summer 8-12-2017

Degree Type

Thesis

Degree Name

Master of Science - Agriculture

Department

Agriculture

First Advisor

Dr. Michael Maurer

Second Advisor

Dr. Jared Barnes

Third Advisor

Dr. Josephine Taylor

Abstract

Three experiments evaluated pinching and spacing on Helianthus annuus in East Texas to determine their effects on growth and development. Experiment 1 was designed to determine the effects of pinching nodes 1, 2, 3, or 4 on ‘Pro Cut Gold’ sunflowers. Results from experiment 1 showed non-pinched plants produced marketable stem lengths and flower sizes, while pinched plants’ stem length, stem diameter, flower diameter, and disk diameter decreased compared to the non-pinched plants. The objective for experiment 2 was to evaluate pinching and spacing treatments on ‘Pro Cut Gold’ sunflowers. All spacings for non-pinched plants in experiment 2 produced marketable stem lengths and flower sizes. Experiment 3 was designed to analyze the effects of pinching nodes 1, 2, 3, or 4 on ‘Pro Cut Gold, ‘Supreme Sunbright’, ‘Vincents Choice’, ‘Sunrich Lemon’, and ‘Superior Gold’ sunflowers. All of the non-pinched plants for all five cultivars produced marketable stem lengths and flower sizes. Pinching responses varied by cultivar but overall stem length, stem diameter, flower diameter, and disk diameter all decreased compared to the non-pinched plants. ‘Vincents Choice’ pinched at the first node was the only cultivar when pinched to produce a marketable stem length and flower size. A successful pinching in East Texas is dependent on planting early into the growing season (May). Spacing did not clearly affect sunflower growth and development; therefore, increasing planting densities of non-pinched sunflowers could increase marketable stem yield compared to pinching sunflowers at lower planting densities.

Repository Citation

Burnett, Rebecca B., "Pinching and Spacing Effects on Cut Sunflower (Helianthus annuus) Production in East Texas" (2017). Electronic Theses and Dissertations. 121.
https://scholarworks.sfasu.edu/etds/121