DETERMINATION THE EFFECT OF DEFOLIATION TIMING ON COTTON YIELD AND QUALITY

This study was carried out for determining the effect of different application times at 40, 50, 60 and 70 % boll opening and untreated plot of the defoliant on cotton yield, earliness and technological properties in Southeast Anatolia Region conditions in Turkey. Maras 92 cotton variety was used as plant material in the experiment field of the Southeast Anatolia Agricultural Research Institute during 2000-2001. Defoliant was including thidiazuron + diuron chemical substance. The result of this study showed that ginning percentage, 100 seed weight, seed germination percentage, fiber fineness, fiber length, fiber strength, reflectance, elongation and seed cotton yield were not affected by the treatment; plant height and first picking percentage in 2001, fiber uniformity in 2000 were 5 % significantly affected. This study showed that application of defoliant didn’t affect significantly yield and technological properties of cotton and after 40 % boll opening the defoliant can be used.