Response of different cotton cultivars to water stress on water-yield relations under drip irrigation conditions in Aydın Plain

In order to observe the effects of deficit irrigation on water-yield relations and water use efficiency of Carisma (V1), Candia (V2) and Gloria (V3) cotton cultivars, a field trial was conducted in year 2018 at the Aydın plain conditions. The trial was designated in randomized complete block design with two factors and three replications. In the trials, irrigation water was applied to cotton cultivars using drip irrigation method as 100%, 67%, 33% and 0% of evaporation from Class A Pan corresponding to 8-day irrigation frequencies. The applications of water significantly affected raw cotton yield. The seasonal water use of cotton varied between 206 and 826 mm according to cultivars. The average raw cotton yield varied from 187-630 kg da-1. The highest average raw cotton yield was obtained from S1 treatment (Carisma-V1) as averaging 630 kg da-1. It was determined Carisma (V1) cultivar performed higher yields than Candia (V2) and Gloria (V3) Average water use efficiency (WUE) values varied between 0.735 and 1.134 kg m-3. Yield response factor (ky) was found to be 0.75 for Carisma (V1) 0.80 for Candia (V2) and 0.78 for Gloria (V3). It may be concluded that the treatment which gave the best performance whether for water saving or for high WUE was treatment S1 (Carisma-V1) when the water was abundant. In the case of water scarcity, S2 (Carisma-V1) treatment resulted in reasonable yield and WUE.