Yield performance at three nitrogen rates of a set of honeycomb vs traditional pedigree selected bread wheat varieties
The honeycomb nil interplant competition selection procedure has been proposed as effective breeding methodology in developing high yielding and broadly adapted wheat varieties. The objective of this research were to (i) evaluate the performance under low and high nitrogen (N) fertility of a set of honeycomb vs traditional pedigree selected bread wheat varieties and (ii) to compare the effectiveness of honeycomb vs traditional pedigree selection in developing high yielding and broadly adapted wheat varieties. Seven F-2 populations, which underwent honeycomb selection in the F, for grain yield (GY), were the basic material for the derived F-9 varieties used in this study. Three population were selected as promising (HC-PR) and four were discarded (HC-D). From each HC-PR the selected material entered honeycomb selection through the F-6 and the high and corresponding low yielding genotypes (HY and LY) were advanced to the F, The honeycomb F, discarded material from each HC-PR entered traditional pedigree selection and resulted in developing the corresponding F9 varieties (TPS). Then for each HC-PR a set of three varieties, including the HY its LY counterpart and their corresponding TPS, was formed. A 4th set including four F9 varieties, one from each HC-D, developed through traditional pedigree (TPS) was also formed. These 13 varieties along with four commercial check varieties were grown with 0, 90 and 180 KgN ha(-1) in a 2 year field study. Grain (GY) and biomass (BY) yield, harvest index (HI) and 1000 kernel weight (Kwg) were recorded. Both, the TPS and LY varieties yielded equal to or significantly outyielded their HY counterparts at all N treatments. This yielding superiority was associated with higher HI and heavier kernels. In the same manner the TPS varieties of the 4th set were equal to or superior than the HY for GY, HI and Kwg. Data indicated that honeycomb method selected mainly for environmental effects and/or high biomass yielding ability combined with poor N using efficiency genotypes. Data indicated that the honeycomb breeding methodology was nearly equal to or less effective than the traditional pedigree. (C) 2002 Elsevier Science B.V. All rights reserved.