الفهرس 
Wheat cultivars performanceOnly 14 pages are availabe for public view
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Abstract
Managing Nitrogen inputs in wheat production systems is an important issue in order to achieve máximum profitable production, and minimum negative environmental impact. This experiment was carried out at Etay EL-Barood, Agricultural Research Station, EL- Behaira Governorate, Egypt during the two successive growing seasons 2018 and 2019 . The main objective of this investigation was to determine types of gene action, heterosis and combining ability for some growth and their interactions with three nitrogen fertilization levels for half diallel cross between seven wheat genotypes namely, Giza 171 (P1), Misr 1 (P2), Misr 2 (P3), Gemmeiza 12 (P4), Gemmeiza 10 (P5), Gemmeiza 9 (P6), Sids 1 (P7) and its new 21 recombination’s. Mean squares due to parents were significant for all the traits studied. P1 (Giza 171) behaved as the earliest one for heading date, 1000- grain weight and flag leaf area. The four crosses P1xP2 (Giza 171x Misr 1), P1xP5 (Giza 171x Gemmeiza 10), P4xP5 (Gemmeiza 12x Gemmeiza 10) and P5xP7 (Gemmeiza 10 x Sids 1) had the highest grain yield per plant. For biological yield per plant, the crosses P2xP6 (Misr 1x Gemmeiza 9), P2xP7 (Misr 1x Sids 1) and P6xP7 (Gemmeiza 9x Sids 1) exhibited significant positive heterotic effects under three levels (25), (50) and (75) Kg.N./fed and the combined data. Parent P1 (Giza 171) exhibited significant positive ( i gˆ ) effects for plant height, number of grains per spike, height up to flag region, 1000- grain weight and flag leaf area, at 25, 50, 75 nitrogen rates and the combined analysis