Abstract :
To evaluate effect of photosynthate availability under terminal heat stress on yield and yield components of wheat, this research was conducted in a split plot experiment based on randomized complete block design (RCBD) with three replications at the Research Farm of Islamic Azad University of Ahvaz in 2015 cropping season. Treatments were defoliation in four levels: removal of two upper leaves, flag leaf removal, complete removal of spikelet at one side of spike and control (non-manipulated) which assigned to main plots and three planting date including (Nov. 21st , Dec. 5st and Dec. 21st ) to subplots. Results showed that defoliation had significant effect on number of grains/spike, 1000 grain weight, grain yield, biological yield and harvest index at one percent probability level. Planting date also affected number of spike/m2, number of grains/spike, 1000 grain weight, grain yield, biological yield, and harvest index significantly at one percent probability level. The interaction effect of defoliation and planting date on the number of grains/spike, 1000 grain weight, grain yield, biological yield and harvest index was also significant. The highest grain yield (5691 kg.ha-1) belonged to the control treatment (no defoliation) at first planting date (Nov. 21st). This was due to the not coinciding filling periods to terminal heat stress of growing season where maximum assimilates were produced. The lowest grain yield (2123 kg.ha-1) belonged to delayed sowing and removal of spikelet at one side of spike. Maturity of plants during 3rd planting date (Dec. 21st) was coincided to heat stress and thus reduced assimilate production.
References:
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Abdoli, M., M. Saeidi, S. Jalali-Honarmand, S. Mansourifar, M.E. Ghobadi, and K. Cheghamirza. 2013. Effect of source and sink limitation on yield and some agronomic characteristics in modern bread wheat cultivars under post anthesis water deficiency. Acta Agriculture Slovenica. 101: 173-182.
Ahmadamini, T., B. Kamkar, and A. Soltani. 2011. The effect of planting date on partitoning coefficient in some species of wheat. Electronic Journal Crop Production. 4(1): 131-150. (In Persian).
Ahmadi, A., A. Siosemordeh, and A. Zali. 2004. Compare saving ability and remobilization of assimilate matter and share of them at four genotypes yield under optimum irrigation condition and drought stress. Iranian Journal of Agriculture Science. 35: 82-93.
Alam, M., A. Rahman, M. Nesa, S. Khan, and N. Siddquie. 2008. Effect of source and/or sink restriction on the grain yield in wheat. Journal of applied sciences research. 4: 258-261.
Alizadeh, O., K. Farsinejad, S. Korani, and A. Azarpanah. 2014. A study on source-sink relationship, photosynthetic ratio of different organs on yield and yield components in bread wheat (Triticum aestivum L). International Journal of Agriculture and Crop Sciences. 5(1): 69-79.
Bijanzadeh, E., and Y. Emam. 2010. Effect of defoliation and drought stress on yield components and chlorophyll content of wheat. Pakistan Journal of Biological Sciences. 13: 699-705.
Birsin, M. A. 2005. Effects of removal of some photosynthetic structures on some yield components in wheat. Tarim Bilimleri Dergisi. 11: 364-367.
Felekari, H., M. Eghbal Ghobadi, M. Ghobadi, S. Jalali Honarmand, and M. Saeidi. 2014. The effect of post anthesis source and sink limitation in wheat cultivars under moderate condition. International Journal of Biosciences. 5(5): 52-59.
Mahfoozi, S., and S. Jasemi. 2010. Study of the possibility of increasing grain yield by increasing grain weight in winter and facultative wheat genotypes with manipulating sink capacity. Iranian Journal of Crop Sciences. 12: 76-84. (In Persian).
Maydup, M. L., M. Antonietta, J. J. Guiamet, C. Graciano, J. R. Lopez, and E. A. Tambussi. 2013. The contribution of ear photosynthesis to grain filling in bread wheat (Triticum aestivum L.). Field Crops Research. 119: 48-58.
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Najafian, G., and A. Shabani. 2010. The effects of terminal water stress on physiological cahractersitics and sink-source relations in two bread wheat (Triticum aestivum L.) cultivars. Iranian Journal of Crop Sciences. 12: 392-408. (In Persian).
Nouriyani, H. 2015. Effect of paclobutrazol on the amount of redistribution of assimilates to the grain of three cultivars of wheat (Triticum aestivum L.) under heat tension conditions. Crop Physiology Journal. 7(25): 89-104. (In Persian).
Papakosta, D. K., and A. A. Gayianas. 2014. Nitrogen and dry matter accumulation, remobilization and losses for Mediterranean wheat during grain filling. Agronomy Journal. 83: 804-807.
Radmehr, M., and A. Naderi. 2005. A study on source-sink relationship of wheat genotypes under favorable and terminal heat stress conditions in Khuzestan. Iranian Journal of Crop Sciences. 7: 112-120. (In Persian).
Radmehr, M., Gh. A. Ayneh, and A. Naderi. 2004. A study on source-sink relationship of wheat genotypes under favorable and terminal heat stress condition in Khuzestan. Iranian Journal of Crop Sciences. 6(2): 101-113. (In Persian).
Reynolds, M., M. J. Foulkes, G. A. Slafer, P. Berry, M. A. J. Parry, J. W. Snape, and W. J. Angus. 2013. Raising yield potential in wheat. Journal of Experimental Botany. 60: 1899-1918.
Rosati, A., and T. M. Djong. 2003. Estimating photosynthetic radiation use efficiency using incident light and photosynthesis of individual leaves. Annals of Botany. 91: 869-877.
Rosati, A., S. G. Metcalf, and B. D. Lampinen. 2012. A simple method to estimate photosynthetic radiation use efficiency of canopies. Annals of Botany. 101: 567- 574.
Saeidi, M., and F. Moradi. 2011. Effect of post-anthesis water stress on remobilization of soluble carbohydrates from peduncle and penultimate internodes to the developing grains of two bread wheat cultivars. Iranian Journal of Crop Science. 13(3): 548-564. (In Persian).
Saeidi, M., F. Moradi, A. Ahmadi, R. Spehri, G. Najafian, and A. Shabani. 2010. The effects of terminal water stress on physiological characteristics and sink-source relations in two bread wheat (Triticum aestivum L.) cultivars. Iranian Journal of Crop Science. 12(4): 392-408. (In Persian).
Saeidi, M., F. Moradi, and S. J. Honarmand. 2011. Contribution of spike and leaves photosynthesis and soluble stem carbohydrates remobilization in grain yield formation in two bread wheat cultivars under post-anthesis stress conditions. Seed and Plant Production Journal. 27: 1-19. (In Persian).
Savin, R., and G.A. Slafer. 1991. Shading effects on the yield of an Argentinean wheat cultivar. Journal of Agricultural Science116: 1-7.
Scott, R.K., and K. W. Jaggard. 2013. Impact of weather, agronomy and breeding on yields of sugar beet grown in UK since 1970. Journal of Agricultural Science Cambridge. 134:341-352.
Shahryari, R., E. Gurbanov, A. Gadimov, and D. Hassanpanah. 2014. Tolerance of 42 bread wheat genotypes to drought stress after anthesis. Pakistan Journal of Biological Sciences. 11(10): 1330-1335.
Tavakoli, A., A. Ahmadi, and H. Alizade. 2009. Some aspects of physiological performance of sensitive and tolerant cultivars of wheat under drought stress conditions after pollination. Iranian Journal of Crop Science. 40(1): 197-211. (In Persian).
_||_Abdoli, M., and M. Saeidi. 2013. Evaluation of water deficiency at the post anthesis and source limitation during grain filling on grain yield, yield formation, some morphological and phonological traits and gas exchange bread wheat cultivar. Albanian Journal of Agricultural Sciences. 12(2): 255-265.
Abdoli, M., M. Saeidi, S. Jalali-Honarmand, S. Mansourifar, M.E. Ghobadi, and K. Cheghamirza. 2013. Effect of source and sink limitation on yield and some agronomic characteristics in modern bread wheat cultivars under post anthesis water deficiency. Acta Agriculture Slovenica. 101: 173-182.
Ahmadamini, T., B. Kamkar, and A. Soltani. 2011. The effect of planting date on partitoning coefficient in some species of wheat. Electronic Journal Crop Production. 4(1): 131-150. (In Persian).
Ahmadi, A., A. Siosemordeh, and A. Zali. 2004. Compare saving ability and remobilization of assimilate matter and share of them at four genotypes yield under optimum irrigation condition and drought stress. Iranian Journal of Agriculture Science. 35: 82-93.
Alam, M., A. Rahman, M. Nesa, S. Khan, and N. Siddquie. 2008. Effect of source and/or sink restriction on the grain yield in wheat. Journal of applied sciences research. 4: 258-261.
Alizadeh, O., K. Farsinejad, S. Korani, and A. Azarpanah. 2014. A study on source-sink relationship, photosynthetic ratio of different organs on yield and yield components in bread wheat (Triticum aestivum L). International Journal of Agriculture and Crop Sciences. 5(1): 69-79.
Bijanzadeh, E., and Y. Emam. 2010. Effect of defoliation and drought stress on yield components and chlorophyll content of wheat. Pakistan Journal of Biological Sciences. 13: 699-705.
Birsin, M. A. 2005. Effects of removal of some photosynthetic structures on some yield components in wheat. Tarim Bilimleri Dergisi. 11: 364-367.
Felekari, H., M. Eghbal Ghobadi, M. Ghobadi, S. Jalali Honarmand, and M. Saeidi. 2014. The effect of post anthesis source and sink limitation in wheat cultivars under moderate condition. International Journal of Biosciences. 5(5): 52-59.
Mahfoozi, S., and S. Jasemi. 2010. Study of the possibility of increasing grain yield by increasing grain weight in winter and facultative wheat genotypes with manipulating sink capacity. Iranian Journal of Crop Sciences. 12: 76-84. (In Persian).
Maydup, M. L., M. Antonietta, J. J. Guiamet, C. Graciano, J. R. Lopez, and E. A. Tambussi. 2013. The contribution of ear photosynthesis to grain filling in bread wheat (Triticum aestivum L.). Field Crops Research. 119: 48-58.
Modhej, A. 2011. Evaluation physiological relation source and sink at wheat genotypes (Triticum aestivum and T. durum) and Triticale (Triticale hexaploid Lart) under Ahvaz condition. Iranian Journal of Field Crops Research. 9(2): 258-264.
Najafian, G., and A. Shabani. 2010. The effects of terminal water stress on physiological cahractersitics and sink-source relations in two bread wheat (Triticum aestivum L.) cultivars. Iranian Journal of Crop Sciences. 12: 392-408. (In Persian).
Nouriyani, H. 2015. Effect of paclobutrazol on the amount of redistribution of assimilates to the grain of three cultivars of wheat (Triticum aestivum L.) under heat tension conditions. Crop Physiology Journal. 7(25): 89-104. (In Persian).
Papakosta, D. K., and A. A. Gayianas. 2014. Nitrogen and dry matter accumulation, remobilization and losses for Mediterranean wheat during grain filling. Agronomy Journal. 83: 804-807.
Radmehr, M., and A. Naderi. 2005. A study on source-sink relationship of wheat genotypes under favorable and terminal heat stress conditions in Khuzestan. Iranian Journal of Crop Sciences. 7: 112-120. (In Persian).
Radmehr, M., Gh. A. Ayneh, and A. Naderi. 2004. A study on source-sink relationship of wheat genotypes under favorable and terminal heat stress condition in Khuzestan. Iranian Journal of Crop Sciences. 6(2): 101-113. (In Persian).
Reynolds, M., M. J. Foulkes, G. A. Slafer, P. Berry, M. A. J. Parry, J. W. Snape, and W. J. Angus. 2013. Raising yield potential in wheat. Journal of Experimental Botany. 60: 1899-1918.
Rosati, A., and T. M. Djong. 2003. Estimating photosynthetic radiation use efficiency using incident light and photosynthesis of individual leaves. Annals of Botany. 91: 869-877.
Rosati, A., S. G. Metcalf, and B. D. Lampinen. 2012. A simple method to estimate photosynthetic radiation use efficiency of canopies. Annals of Botany. 101: 567- 574.
Saeidi, M., and F. Moradi. 2011. Effect of post-anthesis water stress on remobilization of soluble carbohydrates from peduncle and penultimate internodes to the developing grains of two bread wheat cultivars. Iranian Journal of Crop Science. 13(3): 548-564. (In Persian).
Saeidi, M., F. Moradi, A. Ahmadi, R. Spehri, G. Najafian, and A. Shabani. 2010. The effects of terminal water stress on physiological characteristics and sink-source relations in two bread wheat (Triticum aestivum L.) cultivars. Iranian Journal of Crop Science. 12(4): 392-408. (In Persian).
Saeidi, M., F. Moradi, and S. J. Honarmand. 2011. Contribution of spike and leaves photosynthesis and soluble stem carbohydrates remobilization in grain yield formation in two bread wheat cultivars under post-anthesis stress conditions. Seed and Plant Production Journal. 27: 1-19. (In Persian).
Savin, R., and G.A. Slafer. 1991. Shading effects on the yield of an Argentinean wheat cultivar. Journal of Agricultural Science116: 1-7.
Scott, R.K., and K. W. Jaggard. 2013. Impact of weather, agronomy and breeding on yields of sugar beet grown in UK since 1970. Journal of Agricultural Science Cambridge. 134:341-352.
Shahryari, R., E. Gurbanov, A. Gadimov, and D. Hassanpanah. 2014. Tolerance of 42 bread wheat genotypes to drought stress after anthesis. Pakistan Journal of Biological Sciences. 11(10): 1330-1335.
Tavakoli, A., A. Ahmadi, and H. Alizade. 2009. Some aspects of physiological performance of sensitive and tolerant cultivars of wheat under drought stress conditions after pollination. Iranian Journal of Crop Science. 40(1): 197-211. (In Persian).
