Seed protein content of soybean as affected by spatial variation in field experiments

Abstract

The variation of soybean seed protein content has been investigated in performance trials of maturity group 000 to I genotypes at different locations in the eastern part of Austria between 1992 and 1994. In all experiments evaluated, significant portions of spatial variation were identified which affected seed protein content in the range of -25 to + 30 g/kg. Lattice and neighbour analysis were more efficient than the randomized complete block design in reducing error variance in most experiments. Neighbour analysis was superior to the lattice design when soil trends were changing over short distances or in both longitudinal and latitudinal directions. In most instances, neighbour analysis based on two or three neighbouring plots at each side of a test plot was more efficient than an analysis using only the nearest neighbours. Residuals derived from neighbour analysis were also used to visualize spatial heterogeneity, and clear trends of protein content were identified for particular experimental sites. The ranking of genetic entries was considerably biased by spatial variations, which would have reduced the efficiency of selection for high protein content if genotype performance was not adjusted for field variation.

Improving the precision of cotton performance trials conducted on highly variable soils of the southeastern USA coastal plain

“…Although this study illustrates that cultivar means calculated from RCB and NNA analyses sometime differ in rank for both agronomic and fibre quality traits, we support the conclusions of Stroup et al. (1994), Vollmann et al. (1996), Wu et al.…”

“…2001), soybeans ( Glycine max L.) (Brownie et al. 1993, Vollmann et al. 1996) and maize ( Zea mays L.) (Brownie et al.…”

Trypsin inhibitor activity of soybean as affected by genotype and fertilisation

“…A considerable amount of spatial variation in soybean TIA was first reported by Marchetti et al, 10 who described plant-toplant variation within plots, and is well-documented for other quality characteristics such as seed protein content. 15 TIA was reduced by nitrogen or nitrogen + sulphur application during seed filling (Table 2). In the case of nitrogen this can be interpreted as a dilution effect: while total protein content is increased owing to the availability of additional nitrogen, 17 protease inhibitors are expressed on a more constant level and therefore TIA per unit of protein meal is reduced relatively.…”

“…Soybean genotypes (environment 1: 12 genotypes only; environments 2 and 3: all 18 genotypes) were planted in single-row plots of 2.5 m length with 0.6 m row spacing and 4 cm space between plants within the row. Agronomic parameters including seed inoculation with Bradyrhizobium japonicum (Kirchner) Jordan were set as described by Vollmann et al 15 For each macroenvironment, a split plot design in two replications with fertilization treatments as main plots and genotypes as sub-plots was used as the experimental design. Additionally, genotypes within each main plot were arranged in generalised lattice designs in order to increase the precision of parameter estimation.…”

Soybean

“…Nearest neighbor analysis or lattice designs were found more efficient, compared to randomized complete block designs, in reducing error variance in soybean experiments (Vollmann et al 1996). Helms et al (1995), however, did not find nearest neighbour adjustments useful compared to unadjusted means for yield selection in two populations.…”