Stability of Morphological Traits Conferring Bird Resistance to Sunflower across Different Environments

Abstract

Bird depredation is a major concern of sunflower (Helianthus annuus L.) producers wherever the crop is grown in the world. Development of bird‐resistant varieties would provide an economical, environmentally safe method of contending with the problem. Morphological traits that confer resistance to depredation by birds have been identified. These traits include long involucral bracts, horizontally oriented heads, concave heads, and long head‐to‐stem distances. The objective of this study was to determine the stability of the traits when cultured in different environments. Breeding lines BRS1, ND208, ND492, ND495, ND162, and ND223‐16, which possess resistance traits, and seven susceptible counterparts, ND221, ND224, ND505, HA89, ND581, ND223‐1, and ND223‐3, were grown at three locations in North Dakota in 1988 and 1989. Measurements of the traits were made at the R7 stage of development. Genotype, environment, and genotype ✕ environment effects were all significant (P < 0.05). The genotype ✕ environment interaction effects, however, were not the result of changes in rank between resistant and susceptible genotypes, but represented differences in magnitude of response in the genotypes when grown in diverse environments. Results of this study indicate that performance of hybrids possessing these traits can be expected to be stable across a wide geographical area.

Rates and Effects of Bird Damage on Grain Yield of Oil Sunflower Seedlings

“…Sağlam and Önemli (2005) reported in a similar study that plant characteristics of varieties were more important in the effect of bird damage on crops, especially those with sloping tablets, which were less affected. Likewise, some researchers have found that there are significant differences between varieties in terms of bird damage, and that especially oblique, concave and brachy leaves whose trays are parallel to the ground with ninety degrees angle make bird damage less (Gross et al, 1991;Çoşke and Ulukan 2005;Rauf et al, 2008). The results of research carried out earlier on the plant characteristics of varieties and the results of this research are similar.…”

“…In the 1980s oil of high-quality and efficient hybrid varieties were initiated to be developed, which would reduce bird damage the most. In these studies, species with a thick fibrous body with concave tops, high antioxidant crust, long stem and long brache leaves, more than 15 cm between the stem distance and the table and looking downward as resistant to bird damage were obtained (Gross et al, 1991). In this study, it was aimed to determine the harmfulness of seed yield of birds and the effect of variety characteristics on bird damage by growing 10 different hybrid sunflower cultivars in Kavak district of Samsun province.…”

Growth, Yield and Quality of Bird-Resistant Sunflower Cultivars Found in Genetic Resources

“…We assessed their resistance to feeding by birds in the field and in the laboratory, and compared various seed, plant, and agricultural characteristics to those of a bird-susceptible control F1 hybrid cultivar, 63M80. Gross and Hanzel (1991) identified long involucral bracts, horizontally oriented heads, concave heads, and long head-to-stem distances as features that confer resistance to feeding by birds. In our study, head-to-stem distance was similar among the three cultivars so we could not assess this feature.…”

Strategies for Evading Blackbird Damage

“…The goal was to develop a bird-resistant sunflower while maintaining palatability, yield, and oil content. Scientists surmised the features needed to inhibit perch-feeding and seed access included a flat or concave head shape, tightly held achenes, thick fibrous hulls, hulls with high levels of anthocyanins, long chaffs, long wrap around bracts, a head-to-stem distance of more than 15 cm, and ground-facing flowers (Parfitt 1984;Seiler and Rogers 1987;Gross and Hanzel 1991). Additionally, the percentage of oil, which is correlated with hull thickness, was thought to be a key reason for birds selecting particular varieties of sunflower (Mason et al 1991).…”