Univrsity of Tehran Press Iranian Journal of Field Crop Science 2008-4811 52 1 2021 03 21 Response of Yield and Yield Components of Barley Cultivars to Reduction of Growing Season Response of Yield and Yield Components of Barley Cultivars to Reduction of Growing Season 13 23 80874 10.22059/ijfcs.2020.274198.654617 FA Alireza Khodashenas North Khorasan Agricultural and Natural Resources Research and Education Center, AREEO, Bojnord. Journal Article 2019 06 19 Limited ground water resources provide the large portion of required water for agriculture in Khorasan Razavi province and negative balance in the exploitation of these resources has threatened the continuity of agricultural activity. To reduce water consumption in the agricultural, 4-year study (2011-2014) was conducted in Agriculture and Natural Resources Research and Education Center of Khorasan Razavi on barley. Replicated trials was carried out as split plots in a randomized complete blocks design with three replications, so that planting dates were main plots and barley varieties include Yousof, Nik, Goharan, Kavir, Reihan003, Loot, Bahman and line No. 17 were subplots. Grain yield of the first dating in second year and pending culture in third and fourth years of experiment was 4734, 3199 and 4018 kg/ha, respectively compared to grain yield of autumn culture (check) in third year (4735 kg/ha), decreased 0, 26.2 and 27.4% respectively, whereas 3 times of autumn irrigation (equal to 50% decline in irrigation) was deleted from production cycle. Results showed that by shortening the growing season, yield and yield components of barley were affected and proportionally reduced but in some planting dates and spring cultivars of barley, grain production potential was acceptable and reduction of the growing season of barley and elimination of the autumn irrigations is possible and recommended. On this base, optimal barley planting date with autumn irrigation elimination is pending culture but this date could expanded to 20 of February; although the recommended planting date is the same. In this relation, selection of suitable varieties of barley (adapted spring cultivars such as Goharan, Nik and Yousof) is the next priority to ensure the success of production. Limited ground water resources provide the large portion of required water for agriculture in Khorasan Razavi province and negative balance in the exploitation of these resources has threatened the continuity of agricultural activity. To reduce water consumption in the agricultural, 4-year study (2011-2014) was conducted in Agriculture and Natural Resources Research and Education Center of Khorasan Razavi on barley. Replicated trials was carried out as split plots in a randomized complete blocks design with three replications, so that planting dates were main plots and barley varieties include Yousof, Nik, Goharan, Kavir, Reihan003, Loot, Bahman and line No. 17 were subplots. Grain yield of the first dating in second year and pending culture in third and fourth years of experiment was 4734, 3199 and 4018 kg/ha, respectively compared to grain yield of autumn culture (check) in third year (4735 kg/ha), decreased 0, 26.2 and 27.4% respectively, whereas 3 times of autumn irrigation (equal to 50% decline in irrigation) was deleted from production cycle. Results showed that by shortening the growing season, yield and yield components of barley were affected and proportionally reduced but in some planting dates and spring cultivars of barley, grain production potential was acceptable and reduction of the growing season of barley and elimination of the autumn irrigations is possible and recommended. On this base, optimal barley planting date with autumn irrigation elimination is pending culture but this date could expanded to 20 of February; although the recommended planting date is the same. In this relation, selection of suitable varieties of barley (adapted spring cultivars such as Goharan, Nik and Yousof) is the next priority to ensure the success of production. https://ijfcs.ut.ac.ir/article_80874_43941cb0a8a5cd15b257c85173e78326.pdf