Effect of end season water stress on yield of nine rice cultivars and promising lines based on drought evaluation indices

Subject Areas : Agroecology Journal

Mohammad. Bager Khorshidi ^{1 *} , Mehrdad Abdi ² , Shahram Iranipur ³ , Rahim Akbari ⁴

1 - Assistant Professor of Islamic Azad University, Miyaneh Branch, and Natural Resources and Agriculture Research Center of Azarbayejan e Sharqi Province
2 - Assistant Professor of Islamic Azad University, Miyaneh Branch
3 - M. Sc. in Agronomy, Members of Jihad e Agriculture Organization, Miyaneh
4 - M. Sc. in Agronomy, Members of Jihad e Agriculture Organization, Miyaneh

Received: 2007-12-17 Accepted : 2008-07-26 Published : 2008-08-22

Keywords: Water stress, yield, Rice, Drought evaluation indices,

Abstract :

This research was carried out to determine the effect of end season water stress on yield of nine cultivars and promising lines by using drought evaluation indices in Miyaneh region of Iran. A split plot experiment was conducted based on randomized complete block design (RCBD) with four replicates. Five drought evaluation indices including MP, GMP, TOL, STI and SSI were calculated. Results showed that there were significant differences among cultivar’s yield. Saleh, 830, Local 2nd and Hybrid cultivars or lines produced higher yield than their group mean. Cultivar Hassan sarayi produced higher yield than stress condition mean, but line 841 showed lesser yield than stress condition mean. In control condition, line 840 produced higher yield than group mean, but in stress condition produced low yield. Hashemi, Local 1st and 841 produced low yield in both conditions. Highest STI belonged to Saleh, 830 and Local 2nd as 1.5, 1.26, and 1.02, respectively. Based on GMP, Saleh was a high tolerant cultivar (8444 kh/ha). However, Hashemi was more tolerant than Saleh based on SSI and TOL and Saleh showed higher tolerance by MP. Ys and Yp correlation coefficients comparison with drought evaluation indices pointed that MP, GMP, and STI, had higher correlation with two conditions and were assumed as the best drought evaluation indices for screening tolerant and susceptible rice genotypes. By these indices, Saleh was the most tolerant cultivar and 830 was the second one.