The Effects of Sowing Date and Sowing Density on Birds Damage in the Cultivars of Sunflower (Helianthus annuus L.)

A research in Barbaros city belong to Tekirdag centre county as farmer condition was carried out determination of bird damage ratio on the sown fields. The demonstration used three sunflower varieties (Super 25, Pioneer 6482, Sunbred 281), two sowing dates (16.04.1997 and 14.05.1997) and four sowing densities (20, 30, 40 and 50x70cm) was established according to split-split plot design. The determination characters are seed yield per decare unless bird damage, bird damage ratio, plant height, stem diameter, circumference, plant seed yield, 1000 seed weight, protein ratio and oil ratio. Variety, sowing date, sowing density and their interactions effected significantly, on the bird damage ratio. Early sowing in Sunbred 281 on 20 x 70 cm increased the seed yield per decare as 59.91 % according to later sowing. This variety in early sowing on 50 x 70 cm and 20 x 70 cm sowing density exposed to bird damage with 37.79 and 34.80 % respectively. Early sowing together with all varieties and sowing densities increased yield as 31.72 % according to later sowing date. It was exposed to 18.27 % bird damage while laters owing had 2.49 % damage ratio. In addition, it is determined that varieties which have upright sunflower tray and early maturing were exposed to more bird damage according to the variety Pioneer with downright sunflower tray and later maturing 20 x 70 cm sowing density exposing upright tray had the most bird damage.