Efficiency of assimilates and nitrogen remobilization in lines and cultivars of grain sorghum under drought stress condition(in Neyshabur)

• Main Authors: Beheshti, Alireza, Basafa, A, Azari Nasrabad, M, Foman, A, Jafariyani, M, Beshartnia, G, Ahmadpor, A
• Format: Publication
• Language: Persian
• Published: Karaj (Iran) Seed and Plant Improvement Institute - SPII 2013
• Subjects: ASIMILACION; ASSIMILATION; SORGHUM BICOLOR; VARIEDADES; VARIETE; VARIETIES

Water and nitrogen are the two essential factors for crop production in arid and semiarid regions. Reports indicate low efficiency for both factors in current farming of the country. The efficiency of assimilates and nitrogen remobilization in lines and cultivars of grain sorghum under drought stress condition was studied in Khorasan Razavi, Neyshabour Agricultural Research Station during 2011-2012 crop season. Statistical designe was split plot based on RCBD with three replications. Treaments were: Normal Irrigation for full crop season(check) and limited irrigation( water cutting through out reproductive period) in main plots and a factorial combination of N( 0 and 200 kg N ha-1 ) and five sorghum cultivar and promising lines ( commercial Var., Sepideh and MGS5, MGS2, KGS29 and KGS33 lines) in subplots. Deleting N, caused reducing growth period, No of seed per panicole, grain yield, harvest index, content of Assimilate Remobilization Dry Matter(ARDM), Remobilization Efficiency(REE) and Remobilization Percent(REP) for both years, comparing to check. Also there were significant effects for Nitrogen Remobilization Efficiency (NRE) and Nitrogen Use Efficiency(NUE) by N and water treatments in first year. NRE value for check treatment(200 kg N ha-1) was 25.6%. Among sorghum genotypes, the Nitrogen Utilization Efficiency (NTUE) and NRE were significant and lines MGS2 and MGS5 had better performance. Water cutting at the begining of reproductive stage, reduced the ARDM and REE at the first year but increased them in second year. In general the adequate soil N content is nessesary for optimum crop growth and maximum photosynthesis activities. Water cutting could reduce grain yield by 16%, but as to the content of water saving, it is economic and recommended. Also the lines MGS5 and KGS29 are recommended for their high grain yield in these situations.