Using of spatial analysis to improve precision in agronomic trials of bread wheat (triticumaestivum l.) [electronic resource].

Includes reference.

Soil heterogeneity often decreases precision in large yield trials. Estimation of, and adjustment for fertility trends within a trial may increase precision. Two methods for estimating fertility trends (or spatial variation) are least squares smoothing and papadakis (nearest neighbor analysis) were evaluated in two experiments of bread wheat. and compared them with the classical analysis such as randomized complete block (RCB) and triple lattice designs. Two experiments were carried out at Gemmieza Research Station in 2001/2002 and 2002/2003 seasons. The experimental design was 10 X10 triple lattice. Each experiment consisted of a trial with three replications of 88 lines of bread wheat and 12 local cultivars namely; (Gemmeiza 3, Gemmeiza 5, Gemmeiza 7, Gemmeiza 9, Gemmeiza 10, Giza 164, Giza 168, Giza 170, Sakha 8, Sakha 61, Sakha 69 and Sakha 93). It could be summarized that: The resultsshowed that the papadakis method was superior for all other used types of analyses in the two seasons. It decreased the percentage values of experimental error for RCBD from 67.604% and 57.404% to 2.85% and 2266% in both seasons,respectively. Lattice was less than least squares smoothing and papadakis in reduction percentage in EMS. Also papadakis method was more effective for reducing CV. and raising the precision as other types of analyses. Lattice and least squares smoothing gave little reduction in CV. Correlation coefficients for adjusted means for lattice and least squares smoothing were more highly with RCBD, showing that either of these two methods gave similar results in this data set, and the general ran kings of the genotypes were similar RCB means. It could be concluded that spatial analysis can improve the efficiency of field trials.

Summary in Arabic.

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