عنوان مقاله [English]
Leaf area index (LAI) and extinction coefficient (K) of wheat are the important parameters for estimation of intercepted solar radiation (RsL). Wheat daily intercepted solar radiation has been measured in many researches, but they are not suitable for using on shorter time increments. The beam angle of solar radiance differed on different hour in day and it must be considered for estimation of hourly RsL (SH) for crop growth models. For estimation of hourly RsL of wheat, an experiment was conducted in fields of Agricultural College at Shiraz University in winter 2009 and spring 2010. The values of hourly RsL, was measured using the difference between the values of measured solar radiation at upper and under the canopy. The results showed that the crop LAI increased after planting and reached maximum (4.89) on 174 days after planting and remained constant for 21 days. The values of wheat intercepted solar radiation was predicted using a method presented by other investigators and the minimum and maximum values of SH were estimated 0.064 and 0.41 when the values of LAI were 1.8 and 4.89, respectively.
امام، ی. 1386. زراعت غلات. چاپ سوم، انتشارات دانشگاه شیراز، 190صفحه.
مداح یزدی، و.، سلطانی، ا.، کامکار، ب.، زینلی، ا. 1387. فیزیولوژی مقایسهای گندم و نخود: شاخص سطح برگ، دریافت و استفاده از تابش و توزیع ماده خشک به برگ ها. مجله علوم کشاورزی و منابع طبیعی، 15:(4).
Duncan, W. G., Loomis, R. S., Williames, W. A., Hanau, R. 1967. A model for simulating in plant communities. Hilgardia, 38(2): 181-205.
Gallagher, J. N., Biscoe, P. V. 1987. Radiation adsorption, growth and yield of cereals. J. Agric. Sci., Camb., 91(19): 47-60.
Gregory, P. J., Tennant, D., Belford, R. K. 1992. Root and shoot growth, and water and light use efficiency of barley and wheat crops grown on a shallow duplex soil in a mediterranean-type environment. Aust. J. Agric. Res., 43(3): 555-573.
Gregory, P. J., Eastham, J. 1996. Growth of shoots and roots, and interception of radiation by wheat and lupin crops on a shallow, duplex soil in response to time of sowing. Aust. J. Agric. Res., 47(3): 427-447.
Jones, H. G. 1992. Plants and Microclimate, 2nd edition. A quantitative approach to environmental plant physiology. Cambridge University Press, 433 p.
Kiniry, J. R., Simpson, C. E., Schubert, A. M., Reed, J. D. 2004. Peanut leaf Area index, light interception, radiation use efficiency, and harvest index at three sites in Texas. Field Crops Res., 91(2): 297-306.
Kiniry, J. R., Jones, C. A., O’toole, J. C., Blanchet, R., Cabelguenne, M., Spanel, D. A. 1989. Radiation-use efficiency in biomass accumulation prior to grain-filling for five grain-crop species. Field Crops Res., 20(1): 51-64.
Mahbod, M., Zand-Parsa, Sh., Sepaskhah, A. R. 2013. Influences of air temperature, irrigation regimes and nitrogen application rates on radiation use efficiency of winter wheat. Arch. Agron. Soil Sci., 60(1): 49–66.
O’connell, M. G., Leary, G. J., Whitfield, D. M., Conner, D. J. 2004. Interception of photosynthetically active radiation and radiation-use efficiency of wheat, field pea and mustard in a semi-arid environment. Field crops Res., 85(2-3): 111-124.
Siddique, K. H. M., Belford, R. K., Perry, M. W., Tennant, D. 1989. Growth, development and light interception of old and modern wheat cultivars in a Mediterranean-type environment. Aust. J. Agric. Res., 40(3): 473-487.
Sinclair, T. R., Hoare, T. 1989. Leaf nitrogen, photosynthesis, and crop radiation use efficiency: a review. Crop Sci., 29(1): 90-98.
Ricardo, A., Claudio, O. S., Mattew, D. W. 2007. A simple approach to modeling radiation interception by fruit tree orhard. Agric Forest Meterol., 142(1): 12-24.
Thorne, G. N., Pearman, I., Day, W., Todd, A. D. 1988. Estimation of radiation interception by winter wheat from measurements of leaf area. J. Agric Sci., 110(1): 101-108.
Yunusa, I. A. M., Siddique, K. H. M., Belford, R. K., Karimi, M. M. 1993. Effect of canopy structure on efficiency of radiation interception and use in spring wheat cultivars during the preanthesis period in a Mediterranean-type environment. Field Crops Res., 35(2): 113-122.
Zand-Parsa, Sh., Sepaskhah, A. R., Ronaghi, A. 2006. Development and evaluation of integrated water and nitrogen model for maize. Agric. Water Manage., 81(3): 227-235.