R Karimizade, B Vaezi, T Hoseyn Por, A Mehraban, H Ghojagh,
Volume 13, Issue 48 (7-2009)
Abstract
Multi-environment trial data are required to obtain stability performance parameters as selection tools for effective cultivar evaluation. The interrelationship among several stability parameters and their associations with mean yield, along with the repeatability of these parameters in consecutive years was the objective of this study. Barley yield data of 18 cultivars, proprietary of Dryland Agricultural Research Institute, evaluated in 12 locations over 2005-2007 in three locations of Iran was used for the combined analysis of variance in three datasets. I: Across locations in a single evaluation year (dataset A), II: Across locations in each of two single evaluation year (dataset B), III: Across all locations in three years (dataset C). For each dataset, cultivar phenotypic variance and other statistics were appropriately partitioned in its components. The interrelationship among the parameters and their associations with mean yield based on Spearman rank correlation was studied in each of the three single evaluation years (dataset A). Rank correlation coefficients were also used as estimates of the repeatability of these stability parameters across two year combinations (dataset B). The parameters 2 σi Shukla and 2 Wi were consistently highly correlated with each other but not with mean yield in all single and pair evaluation years. The parameters bi , 2 Si and CV were consistently highly correlated with each other but not with mean yield in all single and pair evaluation years. Result showed that Shukla variance, Wricke ecovalence, SIPC1 and ASV AMMI stability statistics have high repeatability. Thus it is suggested that more stability statistics especially nonparametric methods be used for determination of repeatability methods.
A. Rigi Karvandri, A. Mehraban, H. R. Ganjali, Kh. Miri, H. R Mobser,
Volume 23, Issue 4 (winter 2020)
Abstract
Water scarcity is the most important factor constraining agricultural production all over the world and water shortage in agriculture must be established to use the deficit irrigation. In order to study the effects of the regulated deficit irrigation and partial root zone drying on the growth traits of Rosmarinus Officinalis L., an experiment was conducted in the center of seed and plant production of IranShahr municipality in 2017. The experiment treatments were arranged as a randomized complete block design with three replications. The irrigation regimes consisted of full irrigation, regulated deficit (RDI75 and RDI55) and partial root zone drying irrigation (PRD75 and PRD55). The results showed that deficit irrigation at 75 and 55 percent of full irrigation resulted in saving 18.6 and 34.3 percent of water consumption, respectively. Comparison of full irrigation and PRD75 showed that dry weight, height of plants and number of shoots per plant were decreased by 6.7, 14.3 and 12.1 percent, respectively. However, proper development of root in PRD75 increased 12.9 percent of water productivity. Therefore, by considering the problems of water scarcity, it is possible to provide PRD75 as a superior treatment and a suitable strategy to cope with the water crisis in order to move towards a sustainable agricultural system.
