Knezha 461 – A new maize hybrid from the middle early group

N. Petrovska*, V. Valkova

Maize Research Institute, 5835 Knezha, Bulgaria
(Manuscript received 14 May 2018; accepted for publication 14 September 2018)

Abstract. The article presents the biological and morphological parameters of the new grain maize hybrid from middle early group. The hybrid is acknowledged in 2017, after three years of testing in the territorial station at Executive Agency of Variety Testing, Field Inspection and Seed Control (EAVTFISC) with standard American hybrid P 9494 and Knezha 435, a widespread Bulgarian hybrid. During the period of testing under conditions without irrigation in the experimental field of the Maize Research Institute – town of Knezha the three years average of the new hybrid exceeded the standard P 9494 by 7.4%, and Knezha 435 by 8.6%. In the ecological network of the country in 2011, under conditions without irrigation, the hybrid produced grain yield 2.6% above the foreign and 4.7% above the Bulgarian standard. In 2016 at EAVTFISC the Knezha 461 maize hybrid exceeded by average grain yield the P9494 standard by 1.5%. The testing was conducted at four points under non-irrigated conditions. The moisture content in the harvesting time is near to that of P9494 and lower than the moisture of Knezha 435. The new high-yielding and competitive hybrid Knezha 461 supplies deficiencies in the middle early group of Bulgarian hybrids, where the foreign ones take prevalence.

Evaluation of the combining ability for yield of grain of middle early maize lines

Abstract. The general combining ability (GCA) and specific combining ability (SCA) of twenty-six middle early maize lines was studied by Savchenko’ method. The lines were tested on three testers, with origin of two genetic groups: ХМ 98 40 and КС 05 7 of SSS и ХМ 87 15 of Lancaster. Highest GCA have lines КС 08 12, КС 08 10 and XM 08 8. These lines will be included as components of high-yielding middle early synthetics or as testers in analyzing crosses to determine of GCA in early stages of the selection process. With high SCA are the lines KC 08 29, XM 08 4 and XM 08 10. They could be used in the heterosis breeding for developing of high productive maize hybrids. The line KC 08 17 has both high GCA and SCA and can be used in corresponding breeding programs.

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Breeding evaluation of newly stabilized lines of maize

V. Valkova
Abstract. General Combining Ability (GCA) and Specific Combining Ability (SCA) of sixteen newly stabilized early maize lines were evaluated by Savchenko’s method (1978). The lines were tested in five testers by different genetic groups, possessing established high general combining ability. For testing of productive capacity of the resulting F1 topcross crosses three preliminary variety trials were carried out in the experimental field of the Maize Research Institute, Knezha. The experimental work was carried out in the period of 2009–2011, under conditions without irrigation and plant density 52000 plant/ha. As a result of these experiments, inbred lines with high GCA are pointed out (KC 08 23 and KC 08 27), which are recommended as components of new synthetic populations. The highest is the SCA of inbred lines KC 08 31, KC 08 32 and XM 08 3. These inbreds may be used in heterosis programs for new high yield hybrid creation. Two of the lines (XM 08 1 and KC 08 24) have both high GCA and SCA and can be used in corresponding breeding programs.

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