INFLUENCES OF WINTER COVER CROP RESIDUES AND TILLAGE ON COTTON LINT YIELD AND QUALITY

The cotton growing in Turkey has monoculture system and any crop is not grown in approximately five months between two cotton growing which caused lower seed cotton yield, poor lint quality and early leaf senescence. The influences of different tillage systems and winter cover crops on cotton lint yield and quality were evaluated in Aegean Region of Turkey during two cotton-growing seasons. In second year compared to the first year, the dry matter yield of cover crop root residues increased by 40 % in conventional tillage system and 60 % in no tillage system. Similar increases were also determined for residue organic matter yield in soil. Dry matter and organic matter in soil harvest residues were higher in conventional tillage system as compared to no tillage system. Among cover crop treatments common vetch + oat and hairy vetch + oat mixtures provided the highest dry matter and organic matter in soil harvest residues. Cotton lint yield and quality were not affected by cover crop treatments and tillage systems. Also, tillage by cover crop interactions was non-significant for cotton lint yield and quality. During the observations at 50% boll opening period of cotton, it was monitored that leaf senescence decreased under no-tillage cotton production system in both years