EFFICIENCY  OF  SELECTION  CRITERIA TO IMPROVE MAIZE PERFORMANCE UNDER TOW LEVEL OF NITROGEN. (GROWTH  CRITERIA AND YIELD( Mg/h)).

	EFFICIENCY OF SELECTION CRITERIA TO IMPROVE MAIZE PERFORMANCE UNDER TOW LEVEL OF NITROGEN. (GROWTH CRITERIA AND YIELD( Mg/h)).
journal of kerbala university
Article 1, Volume 7, Issue 3, 2011, Pages 515-524 PDF (0 K)
Abstract
Four selection criteria ; grain /plant (GN) ,anthesis-silking interval(ASI) ,yield efficiency (YE) and leaf area duration (LAD) were tested in selected plants of maize (Zea mays L.) cv.R-106. The experiment was applied for six consecutive seasons( 2009- 2011) on the farm of the Dept.of Field Crops Sci./College of Agric./Univ.of Baghdad . Plants of high grain coincided with the desired criterion were taken , selfed, and harvested for three selection cycles under 200 and 400 kg N/ha . Seeds of third cycle of each selection criterion were planted for panmixia .The resulted seeds were grown in a yield trial for evaluation under 60 and 80 thousands plant/ha in spring and fall seasons .The results showed that low nitrogen plants that were selected for shorter ASI and larger grain number GN increased total dry matter (TDM) by 13.8% and 34.5 for spring season and 14.4% and 37.6%for fall season ,respectively .Days to maturity(DTM) decreased 3days less than original population for ASI for spring and fall season .Crop growth rate(CGR) increased 2.59and 3.65 gm/plant/day for ASI in spring and fall seasons, respectively. Selection cycles also affected the growth criteria of all selected plants under high nitrogen in the same way.(TDM )increased 16.3%,24%,25.3%and 25% in spring season and 24%,37%,39%and 23% in fall season for GN,ASI,YE,LAD respectively. Selection criteria were earlier than original population in (DTM) by1.3,4,2.5and 2.3days in spring season and 2.3,3.7,3.6and 2.5days in fall season, for selection criteria respectively. CGR increased also by 17%,28%,27%,27% and 30.8%,48.5% 55%,32% in spring and fall seasons respectively. Grain yield increased 35.5% , 32%,57%and 34 in spring and fall seasons for ASI,YE respectively. Plant density 80thousandes plant /h decreased TDM , CGR and increased DTM , grain yield (Mg/h) , in high and low nitrogen for both seasons. Selection under high and low levels of N led to improve individual plant performance for many field characters, that resulted in increasing the efficiency of plants that were selected under high and low levels of nitrogen. We recommend the use of these criteria for selection and to develop inbred that will be tolerant to low nitrogen and high densities.

Statistics Article View: 46 PDF Download: 60