Bogdan Bonchev


The experiment was carried out in the experimental field of the Institute of Plant Genetic Resources - Sadovo with common winter cultivar Gaya 1. The study covers the period of two vegetation years 2016-2018. The study period is characterized by contrasting conditions, with drought in April. The potential grain yield of Gaya 1 was calculated by modifying the formula of Edwards (2017). The potential grain yield of Gaya 1 is based mainly on the number of productive tillers of m² and the wight of grains in the spike. They have a direct effect of the potential yield. The grain yield from the square meters of cultivar Gaya 1 is formed mainly by the number of productive tillers / m² with a significant direct effect. Negative indirect effect and strong negative correlation are observed between spike density and grain yield, as well as with potential grain yield. Spike length has a strong positive correlation and a large overall indirect effect with potential grain yield. The correlation between the potential grain yield and the grain yield is strongly positive. A proven decrease in grain yield with a similar trend was found in the potential yield in the second year of the study. The main reason for the decrease in grain yield is the decrease in the number of productive tillers / m2.


potential grain yield, grain yield, Gaya 1, variety maintenance, cultivar direct and indirect effects, correlation

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Alberta Ag-Info Centre (2018). Using 1,000 Kernel Weight for Calculating Seeding Rates and Harvest Losses, Agi-facts, Alberta Agriculture and Forestry,1-6,

Angelova T., Dimitrov E., Uhr Zl. (2020). Estimation of yield and physiochemical parameters of advanced lines of common winter wheat in the region of Central Southern Bulgaria, New knowledge Journal of Science, 9(3), 121-134, ISSN 2367-4598, (Bg)

Arain, M. A., M. A. Sial, M. A. Rajput, A. A. Mirbahar (2011). Yield stability in bread wheat genotypes, Pakistan Jоurnal of Botany, 43, 2071-2074.

Bonchev B. (2020). Morphological markers of common winter wheat and elements of the seed yield in conditions of sowing in October, New knowledge Journal of Science, 9, (1),127-142, 2020, ISSN 2367-4598, (Bg)

Beheshtizadeh, H., Abd. Rezaie, Abd. Rezaie, Akb. Ghandi, (2013). Principal component analysis and determination of the selection criteria in bread wheat (Triticum aestivum L.) genotypes ,International Journal of Agriculture and Crop Sciences , Vol., 5 (18), 2024-2027, IJACS/2013/5-18/2024-2027 ISSN 2227-670X ©2013 IJACS Journal

Boyadjieva, D. (2007). Cultivars of IPGR "K. Malkov" - Sadovo, Cultivars of cereals, brochure, IPGR, Sadovo, 5-21, (Bg).

Boyadjieva, D. (2011). Wheat breeding in Bulgaria. The world wheat book. A History of wheat breeding, vol. 2, Lavoisier, Paris, 2011, 155-174.

Carey, Gr. (1998). Multiple Regression and Path analysis, Regression & Path Analysis,1-14

Chipilski, R. (2016). Physiological and agronomic assessment of drought tolerance of promising varieties of soft wheat, Abstract of PhD Thesis, Sadovo,Bulgaria, 1-33 (Bg).

Dimirov, Gr. (2018). Establishment of genotypes of common winter wheat and peas suitable for organic farming, Abstract of PhD Thesis, Plovdiv, Bulgaria, 4, (Bg).

Dimitrov, E. (2017). Study on immune response of selected winter wheat (Triticum aestivum L) to leaf rust, powdery mildew and Fusarium head blight, Abstract of PhD Thesis, Sadovo, Bulgaria, 1-31 (Bg).

Dimova, D., & Mainkov E. (1999). Experimental work with biometrics. Academic print of AU, 50,93,98 (Bg).

Dimova, D., & Mainkov E. (1999а). Experimental work with biometrics. Academic print of AU, 137-141 (Bg).

Edwards J. (2017). Estimating Wheat Grain Yield Potential, Oklahoma Cooperative Extension, Oklahoma Cooperative Extension Fact Sheets , ServicePSS-2149,

Frost J. (2020). How To Interpret R-squared in Regression Analysis,

Genchev, G., E. Marinkov, V. Yovchev, A. Ognyanova. (1975). Biometric methods in plant growing, genetics and breeding. Zemizdat, Sofia, 226-229, (Bg).

Golparvar A.R., A. Ghasemi-Pirbalouti, H.Madani (2006). Genetic control of some physiological attributes in wheat under drought stress conditions. Pak. J. Bio. Sci. 9(8): 1442-1446.

Leilah A., S. Al-Khateeb. (2005). Statistical analysis of wheat yield under drought conditions, Journal of Arid Environments 61(3):483-496,DOI: 10.1016/j.jaridenv.2004.10.011

Kirchev, Hr., Al. Matev, I. Yanchev, Z. Zlatev (2014). Productivity and its elements of triticale varieties depending on the nitrogen norm, J. Management of sustainable development, 46 (3), 67-70 (Bg),

Koshkin, S.S. (2016). Criteria for assessing the reproductive potential of ancient cultivars of common winter wheat and the possibility of their use in the breeding process, Abstract of PhD Thesis, Krasnodar, 24-28, (Ru).

Krasteva, L. (2012). Jubilee in science, 130 years Agricultural science in Sadovo IPGR “Konstantin Malkov” town of Sadovo (Bg),

Markova-Ruzdik, N. (2015). Characterization of autumn forms of barley (Hordeum vulgare L.) from different geographical origins, Abstract of PhD Thesis, Goce Delchev University, Stip, 1-67 (Mk)

McMaster G.S., Morgan J.A. and Willis W.O. (1987). Effects of Shading on Winter Wheat Yield, Spike Characteristics, and Carbohydrate Allocation. Crop Science, 27-5, 967-973,

Ministry of Agriculture and Foods Industry (1977). Instruction for production of super-elite and elite seeds and planting material from field, vegetable and perennial crops, NPO "Cultivar seeds and planting material", direction "Cultivar maintenance", Sofia, 10 – 12. (Bg).

Ministry of Agriculture and Food Supply (2010). Bulletin. Variety results of recognized for entry in list "A". Varieties of crops and fruit cultivars, KM 135, 11 (Bg), .

Microsoft Excel-Microsoft Corporation, One Microsoft Way Redmond, WA 98052-6399

Neykov, N. (2016). Research of morphology-biological and economic traits of spring barley accessions from the national genebank for the purposes of breeding and production, Abstract of PhD Thesis, Sadovo, 1-29 (Bg).

Okuyama L,; Federizzi L., Barbosa Neto J.(2004). Correlation and path analysis of yield and its components and plant traits in wheat, Cienc. Rural, Santa Maria Nov./Dec., 34 (6), on line ISSN 1678-4596,

Pearl, J. (2018). The Book of Why. New York: Basic Books.,6. ISBN 978-0-465-09760-9.

Rachovska G., Zl. Uhr, Bl. Andonov, K. Kamishev, St. Tosheva (2012). Cereal varieties, brochure, Agricultural Academy-Sofia, IRGR, Sadovo, 8-28 9 (Bg).

Shanin, Y. (1977). Methods for accounting for yield, Methodology of the field experience, Sofia, 124-127 (Bg).

Singh, S.B. (1985). Production, storage and marketing of wheat seed in India. In R.L. Villareal & A.R. Klatt, eds. Wheats for More Tropical Environments. Proc. International Workshop. Mexico, DF, CIMMYT.

Slafer G. A., M. Elia, Roxana Savin, G. García, Ig. Terrile, Ar. Ferrante, D. Miralles, F. González. (2015). Fruiting efficiency: an alternative trait to further rise wheat yield , Food and Energy Security, 4 (2), 92–109.

Styanov, Hr., (2013). Correlation between the spike characteristics in common winter wheat varieties (Triticum aestivum L.) Scientific works, 2(1), 95-104; (Bg).

SAS Institute Inc (2002). JMP, version 5.0.1, A Business unit of SAS 1989 – 2002.

SPSS inc., IBM corporation, Statistical package for the social sciences (SPSS 19)

Tsenov N., Atanasova, D., & Gubatov, T. (2013). Genotype x environment effects on the productivity traits of common winter wheat I. Natute of interacion, Scientific works, Agricultural academy, IA-Karnobat, 2, (1), 57-70;; (Bg).

Vandev, D.L. (2003). Notes on Applied Statistics 1. Probability, Operational Research and Statistics, Faculty of Mathematics and Informatics, Sofia University "St. Kliment Ohridski", 45-56 Sofia, (Bg).

Velcheva, N. (2014). Evaluation of genetic diversity in EX SITU determination tomato collection through statistical methods, Abstarct of PhD Thesis, Sadovo,Bulgaria, 20 (Bg)., Winter common wheat cultivar Gaya 1, Convert Bushels Per Acre to Kilograms Per Hectare.


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