Effect of Paddy Discoloration on Apparent Quality, Milling Properties and Grain Bending Strength

Document Type : Research Paper



Grain discoloration caused by fungi agents, in crop season that the mature grain stage coincides with rain, it causes many damages. In this research effect of paddy discoloration of three varieties (Hashemi, Gohar and Khazar) and disease index in two levels (high and low disease index levels) on grain apparent quality, milling properties and grain bending strength was investigated in a factorial experiment based in randomized complete design with four replications. The milling recovery, degree of whitening, bending strength, length and thickness of the grains (brown rice) in high disease index was significantly lower than those of in low disease index. Also, the broken grains percentage of the three varieties of Hashemi, Gohar and Khazar in high disease index was increased by 5.33, 1.53 and 2.52% as compared to low disease index. Therefore, grain discoloration disease reduces the bending strength and grain size resulting in lower milling recovery, head rice yield and degree of whitening of rice.


Main Subjects

Ahmadi, K., Gholizadeh, H., Ebadzadeh, H., Hosainpour, R., Hatami, F., Fazli, B., Kazemian, A. & Rafiei, M. (2015). Agricultural Statiscal 1394. Volume 1, Crop Products, Mininstry of Jihade of Agriculture, First edition, P54. 
Alizadeh, M. R. (2011). Effect of paddy husked ratio on rice breakage and whiteness during milling process. Australian Journal of Crop Science, 5, 565-562.
Alizadeh, M. A. & Eisavand, H. R. (2006). Rice in Egypt (translation). Office of Agricultural Sciences Encyclopedia, Ministry of Agriculture. (In Farsi)
Asadi, S. Z. (2012). Effect of white tip nematode (Aphelenchoides besseyi) on the physical and biochemical properties of rice seed. MS. C. dissertation, University of Guilan, Iran. (In Farsi)
Asadi, S. Z., Jamali, S., Habibi, F. & Saboori, S. (2013). Effect of white tip nematode (Aphelenchoides besseyi) on the quality properties on Hashemi cultivar. Journal of Cereal Research, 4(1), 69-76. (In Farsi)
Bagheri, I., Dehpour, M. B., Payman, S. H. & Zareiforoush, H. (2011). Rupture strength of brown rice varieties as affected by moisture content and loading rate. Australian Journal of Crop Sciences, 5, 1239-1246.
Candole, B. L., Siebenmorgen, J., Lee, F. N. & Cartwright, R. D. (2000). Effect of rice blast and sheath blight on physical properties of selected rice cultivars. American Association of Cereal Chemists Institute 77(5), 535-540.
De Babandya, M. & Satish, B. (2007). Effect of degree of milling on specific energy consumption, optical maesurements and cooking quality of rice. Journal of Facultative Engineering 80, 119-125.
Dorosti, H. (2011). Hybrid rice technology. Bloor publication, Rasht. (In Farsi)[A1] 
Farouk, S. M. & Islam, M. N. (1995). Effect of parboiling and milling parameters on breakage of rice grains. Agricultural Mechanic in Asia, Africa and Latin America (AMA), 26(4), 33-38.
Guerrero, F. C., Mathur, S. B. & Neergaard, P. (1972). Seed health testing of rice .V. Seed borne fungi associated with abnormal seedlings of rice. In: Proceedings of 37th International Seed Testing Association, 985-997.
Hai, L. H., Kim, P. V., Du, P. V., Thuy, T. T. T. & Thanh, D. N. (2007). Grain yield and grain-milling quality as affected by rice blast disease (Pyricularia grisea), at My Thanh Nam, Cailay, TienGiang. Omonrice 15, 102-107.
Khare, M. N. (1999). Seed health care in seed quality control. Indian Journal of Phytopathology, 52(3), 305.
Koutroubas, S., katsantonis, D., Ntanos, D. A. & Lupotto, E. (2009). Blast disease influence on agronomic and quality traits of rice varieties under Mediterranean condition. Turk Journal Agriculture, 33, 487-494.
Latifi, A., Alizadeh, M.R. (2014). Effect of parboiling on milling and quality characteristics of three varieties of Tarom, Shiroudi and Fajr. Journal of Agricultural Engineering Research, 15(2), 77-88. (In Farsi)
Lu, R. & Siebenmorgen, T. J. (1995). Correlation of head rice yield to selected physical and mechanical properties of rice kernels. Transactions of the ASAE, 38, 889-894.
Mohadesi, M., Bakhshi Poor, S., Abbasian, A., Sattari, M. & Mohammad Salehi, M. (2013). Study on adaptability, quality and quantity characters of rice genotypes in Mazandaran. Journal. of plant production. 20 (2): 19-36. (In Farsi)
Mushtaq, R., Katiyar, S., & bennet, J. (2008). Proteomic analysis of drought stress- responsive proteins in rice endosperm affecting grain quality. Crop Science Biotechnology, 11(4), 227-232.
Nasiri, S. M. & Etesami, S. M. (2015). Energy use efficiency of different drying methods for two rough rice cultivars. Food Science and Technology, 3(2), 23-28.
Nikzad, H. (2013). Study on possibility to predict rice quality based on appearance and strength properties of grain mass. MS. C dissertation, University of Mohagheghe ardebili, Iran. (In Farsi)
Ou, S. H. (1985). Rice disease, 2nd ed. Common wealth Mycological Institute (Common wealth Agricultural Bureaux), Kew, Surrey UK.
Okhovat, S. M. (1999). Cereal diseases (barley, wheat, maize and sorghum). University of Tehran Publication. (In Farsi)
Padasht, F.  &Izadyar, M. (1998). Study on rice brown spot in Guilan province. In: 13th Iranian Plant Protection Congress, Summer 1998, Institute of Agriculture, Karaj, p 83. (In Farsi)
Pan, Z, Amaratunga, K.S.P. & Thompson, J.F. (2007). Relationship between rice sample milling conditions and milling quality. Transaction of the ASABE, 50(4): 1307–1313.
Phat, C. T., Thi Duong, Ch. N. & Thi Du, L. (2005). Influence of grain discoloration to seed quality. Omonrice, 13, 139-144.
Pizzati, C. & Cortesi, P. (2008). Effect of chemicals, nitrogen, time of sowing and panicle brown spot epidemics on rice grain discoloration in Italy. Journal of Plant Pathology 90(2), 197-209.
Saremi, H. (2004). Study on root rot and crown rot of rice in Guilan and Zanjan provinces and introduction relatively resistant races to disease. Agricultural sciences, 41-52. (In Farsi)[A2] 
Van Du, P. H., Cam Loan, L., Duc Cuuong, N., Van Nghiep, H. & Danhthach, N. (2001). Survey on seed borne fungi and its effects on grain quality of common rice cultivars in the Mecong delta. Omonrice, 9, 107-113.
Yang, W., Siebenmorgen, T. G., Thielen, T. P. H. & Cnossen, A. G. (2003). Effect of glass transition on conductivity of rough rice. Biosystems Engineering, 84,193-200.