Influence of sunflower morphological characteristics on achene depredation by birds

• Published in: Agriculture, ecosystems & environment ecosystems & environment, 1987, Vol.20 (1), p.59-70
• Main Authors: Seiler, Gerald J., Rogers, Charlie E.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; birds; characteristics; crop damage; Fringillidae; Fundamental and applied biological sciences. Psychology; Generalities; Genetics and breeding of economic plants; genotype; Helianthus annuus; Pest resistance; Phytopathology. Animal pests. Plant and forest protection; plant morphology; seeds; sparrows; Varietal selection. Specialized plant breeding, plant breeding aims; Vertebrates
• ISSN: 0167-8809; 1873-2305
• DOI: 10.1016/0167-8809(87)90028-4

Bird depredation on sunflower ( Helianthus annuus L.) achenes (seeds) is a serious problem in many parts of the world. The objective of this study was to evaluate the effects of distinctive plant morphological characteristics of six sunflower genotypes (white achene, purple achene, long chaff, tight achene, long bract and commercial hybrid 894) at two stages of plant growth on achene damage by sparrows and finches. The field experiment was conducted over a 2-year period. A split plot with stages as whole plots and genotypes as subplots in a randomized complete block with six replicates was used. Morphological characteristics evaluated for their effect on achene loss by bird feeding included plant height, head diameter, head angle, chaff length, stem angle and distance from top leaf petiole to head. The commercial hybrid 894 had the highest 2-year average achene loss caused by bird feeding (57%), while the tight achene genotype had the lowest average achene loss (20%). Six morphological characteristics (chaff length, head angle, head diameter, plant height, stem angle and distance of top leaf petiole from head) accounted for 50 and 43% ( P = 0.05) of the variation in achene destruction by sparrows and finches in 1983 and 1984, respectively, as determined by multiple regression analyses. Chaff length, head angle, plant height and stem angle consistently accounted for most of the variation in achene destruction each year and are potentially useful morphological characteristics for developing genotypes to deter bird predation on achenes.