Stone mulch offers potential benefits for water conservation in many rain-fed agricultural systems of the arid regions. The effects of stone mulch on transpiration and grain yield were examined for a durum wheat crop grown under soil water deficit stress. In a greenhouse trial, stone mulches with two levels of ground coverage significantly decreased soil-surface evaporation and increased crop transpiration. The transpiration increase contributed to increases both in biomass and grain yield. Field experiments over two cropping seasons confirmed yield increases of 12% in soil half-covered and 24% in soil fully-covered by stones. These significant yield increases indicate the potential usefulness of stone mulch technology in rain-fed cereal cropping. It is suggested that stones should not be removed from cereal fields unless their presence obstructs management severely. It remains to develop technologies for effectively managing soils containing large numbers of sizable stones in order to obtain the benefits of the potential yield increase associated with their presence on the soil surface.
Authors:E. Bakhshandeh, A. Soltani, E. Zeinali, and M. Kallate-Arabi
Crop simulation models use allometric relationships to predict plant height from vegetative characteristics. The objective of this study was to find relationships between plant height (PH) and number of leaves on main stem (NLMS), stem dry weight (SDW) (g plant−1) and total vegetative components (leaves and stems) dry weight (TVDW) (g plant−1) in wheat (Triticum aestivum L.). For this purpose, an experiment was conducted using seven wheat cultivars including two durum wheat cultivars (Arya and Taro) and five bread wheat cultivars (Darya, Kuhdasht, Shiroudi, Tajan and Zagros) under irrigated and rainfed conditions during 2008-2009 at Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. The experimental design was a randomized complete block design with four replications. Sampling was started from beginning of tillering and continued until maturity. A segmented nonlinear regression model was used to describe allometric relationships between PH and the vegetative characteristics. The results showed that there was no significant difference between cultivars and the two conditions for allometric relationships, so one equation was usable for all cultivars under both irrigated and rainfed conditions. Significant relationships were found between PH and NLMS (R2 = 0.94), SDW (R2 = 0.95) and TVDW (R2 = 0.95). These equations can be used for estimation of PH in simulation models of wheat.
Authors:G. Drezner, J. Gunjača, D. Novoselović, and D. Horvat
Nachit, M.M., Nachit, G., Ketata, H., Gauch, H.G., Zobel, R.W. 1992. Use of AMMI and linear regression models to analyze genotype-environment interaction in durumwheat. Theor. Appl. Genet.
Authors:X.G. Hu, J. Liu, L. Zhang, B.H. Wu, J.L. Hu, D.C. Liu, and Y.L. Zheng
Grains of 12 accessions of Triticum timopheevii (Zhuk.) Zhuk. ssp. timopheevii (AAGG, 2n = 4x = 28) and one bread wheat cultivar Chinese Spring (CS) and one durum wheat cultivar Langdon (LDN) grown across two years were analyzed for grain iron (Fe) and zinc (Zn) concentrations. All the 12 tested T. timopheevii ssp. timopheevii genotypes showed significantly higher concentration of grain Fe and Zn than CS and LDN. Aboundant genetic variability of both the Fe and Zn concentrations was observed among the T. timopheevii ssp. timopheevii accessions, averagely varied from 47.06 to 90.26 mg kg−1 and from 30.05 to 65.91 mg kg−1, respectively. Their grain Fe and Zn concentrations between years exhibited a significantly positive correlation with the correlation coefficients r = 0.895 and r = 0.891, respectively, indicating the highly genetic stability. Flag leaf possessed twice or three times higher concentrations for both Fe and Zn than grain, and a significantly high positive correlation appeared between the two organs with r = 0.648 for Fe and r = 0.957 for Zn concentrations, respectively, suggesting flag leaves might be indirectly used for evaluating grain Zn and Fe contents. Significant correlations occurred between grain Fe and Zn concentrations, and between grain Zn concentration and the two agronomic traits of plant height and number of spikelets per spike. Both the concentrations were not related to seed size or weight as well as NAM-G1 gene, implying the higher grain Fe and Zn concentrations of T. timopheevii ssp. timopheevii species are not ascribed to concentration effects of seed and the genetic control of NAM-G1 gene. There might be some other biological factors impacting the grain’s Zn and Fe concentrations. These results indicated T. timopheevii ssp. timopheevii species might be a promising genetic resource with high Fe and Zn concentrations for the biofortification of current wheat cultivars.
Authors:Sonja Maric, Tihomir Cupic, Goran Jukic, Ivan Varnica, and Dario Dunkovic
Akcura M. — Kaya Y. — Taner S.: 2005. Genotype-environment interaction and phenotypic stability analysis for grain yield of durumwheat in the central Anatolian region. Turk J Agric For no. 29 369–375 pp
Authors:O. Bilgin, A. Y. Bilgin, T. Gençtan, and I. BAŞER
Korkut, K. Z., Başer, I., Bilir, S. (1993): Studies on correlation and path analysis in durumwheats. pp. 183-187. Symposium of DurumWheat and Its Products, Ankara.
Studies on correlation and path analysis in durumwheats