Interrelationships of Morphological and Economic Characters of Sunflower1

Abstract

Two phenotypically dissimilar open pollinated sunflower (Helianthus annuus L.) cultivars, ‘Peredovik’ and ‘Tchernianka’, and two hybrids, ‘Romsun 52’ and ‘Seedtec 304’ (produced by genetic and cytoplasmic male sterile systems, respectively), were sown at different dates and seeding rates for two years. The four cultivars were planted as a 4 × 4 latin square. Within each of the four replications, dates of sowing were randomly assigned to strips across the four cultivars. Within each cultivar‐sowing date combination, plant spacings were randomly assigned as 6‐row subplots. Data were collected from ten plants per plot for a number of morphological characters and from the plants in the two center rows for yield and oil characters.Principal component and path coefficient analyses indicate that even though these cultivars are phenotypically and genetically different, the response to date of planting, and the biological systems controlling the interrelationships between morphological, yield, and oil characters are similar. This may explain why some sunflower cultivars are superior at a wide range of locations, and at the same time are sensitive to environmental changes such as planting dates. The results also suggest that yield improvement through better management should apply to many types of cultivars in a wide range of environments.