Water productivity, yield response factors, yield and quality of alfalfa cultivars in semi-arid climate conditions.

This study was carried out for 2 years (2020 and 2021) to elucidate the effects of water stress on yield and quality of alfalfa cultivars, to determine the water-yield and quality relations and the susceptibility of cultivars to water stress. Three different irrigation treatments (100%, 75% and 50% of full irrigation, I 100 , I 75 and I 50) and 12 different alfalfa cultivars (SHN, Osmanağa, Şahin 42, Minerva, Elçi, Riviera Vicentina, Magna 601, Magnum V, Prosementi, Ezzelina, Sunter, Nimet) were used in present experiments conducted in randomized-blocks split-plots design with 3 replications to investigate effects of irrigation levels on water, yield and quality parameters of alfalfa. Present findings revealed that water stress decreased crop water productivity, but increased irrigation water productivity of alfalfa cultivars. Herbage yields of the cultivars varied between 48.20 and 64.98 t/ha, hay yields between 11.42 and 14.67 t/ha and protein yields between 2.22 and 3.07 t/ha. Alfalfa was found to be sensitive to water stress in terms of herbage yield, but more tolerant in terms of hay and protein yields. Morphological characteristics (plant height, number of stems per plant, number of main stem branches and root crown diameter) decreased with increasing water stress levels. In terms of quality traits, while acid detergent fiber (ADF), neutral detergent fiber (NDF), crude fiber and crude ash ratios increased, crude protein ratios decreased with increasing irrigation water levels. It was concluded based on present findings that water stress resulted in different responses of different alfalfa cultivars and although it increased quality traits in general, it decreased herbage, hay and protein yields. Again, based on present findings, Magna 601 cultivar could be recommended for semi-arid regions. • The increase in water stress caused a decrease in the protein ratio while increasing the herbage yield. • Although the same amount of irrigation water was given in alfalfa cultivars, their yields changed significantly. • The increase in water stress also increased the digestibility of alfalfa. • The water productivity of alfalfa varied highly according to the cultivars. • While alfalfa was sensitive to drought in herbage yield, it was tolerant to water stress in hay and protein yield. [ABSTRACT FROM AUTHOR]