Applying statistics for nonsequential yield component analysis - Information

Abstract

In the paper, an application of the methodology for analyzing yield as affected by its components that develop at the same ontogenetic level is discussed; it may also be applied to any model in which several traits developing non-sequentially affect their product. The methodology is called "nonsequential yield component analysis". Two applications are presented; the proposed approach is compared with path analysis, commonly applied for yield component analysis, and Piepho's approach. In one example, grain yield of two cultivars of winter triticale (× Triticosecale Wittmack), Fidelio and Bogo, as affected by harvest index and biomass yield, was studied; the results of the three approaches compared were similar. However, in the study of nitrogen uptake as affected by nitrogen-uptake efficiency and crop nitrogen supply (the problem for which yield component analysis may be applied because of the underlying multiplicative model), the results of the methods were different. For both cultivars, path analysis and Piepho's method showed a much stronger influence of crop nitrogen supply on nitrogen uptake than that of nitrogen-uptake efficiency. In the proposed method, however, both these component traits influenced nitrogen uptake to a similar extent. The proposed method is shown to be methodologically better than the other approaches, and to provide different results in some situations. Hence, the new method should be used for nonsequential yield component analysis although it is suggested that path analysis may be applied if the determination coefficient of the linear model is close to 100%.

Effect of genotype × environment interaction on grain yield factors in durum wheat

“…The findings were not similar may be due to alteration in genetic makeup of genotypes and tested environmental conditions or both. The biological yield is a multiplicative yield integral with harvest index (Kozak et al, 2007). In durum wheat harvest index is an important trait and have direct impact on grain yield.…”

Application of Ash for Amelioration of Salinity Effect in Rice

“…Harvest index (HI) was calculated following the formula given below (Kozak et al, 2007) Grain yield Harvest index (HI) = × 100 Biological yield…”

Multiplicative yield component analysis: what does it offer to cereal agronomists and breeders

“…Still there are some issues to be solved and discusses (for example, methodology for multiplicative yield components that develop in sequential order during ontogenesis, extracting direct and indirect effects from the analysis; see Kozak andMądry 2006 andKozak et al 2007a). Here we will deal with one of such issues, namely how the results of yield component analysis should be used, and what kind of conclusions might be drawn based on them.…”

“…We will also limit the discussion to cereals, for which grain yield is considered as the product of its three following components: number of spikes per unit area, average number of kernels per spike (commonly called number of kernels per spike), and average kernel weight (commonly presented as thousand kernel weight and called the kernel weight). Although cereal grain yield may be also studied as the product of biomass yield and harvest index (Kozak et al 2007a), we will not consider this situation and will focus on what we could call the classical yield components. A set of such classical yield components could probably be defined for any plant species: For legumes, for example, this could be seed yield per unit area considered as the product of number of plants per unit area, number of branches per plant, number of pods per branch, number of seeds per pod and seed weight (Gołaszewski et al 1998); for root species, root yield can be considered as the product of number of plants per unit area and root yield (Hűhn 1987); and so forth.…”