Efficiency of a 3³ factorial design for cotton fertilizer experiments

brag Bragantia Bragantia 0006-8705 1678-4499 Instituto Agronômico de Campinas Campinas, SP, Brazil The purpose of this work was the study of the efficiency of a 3³ factorial design, confounded in blocks of 9 units, in comparison with the completely randomized design. Approximately 300 cotton experiments were conducted during the years of 57/58, 58/59, 59/60 on different kinds of soils of the State of São Paulo. From the results of the experiments in which confounding was employed, we estimated what the experimental error would have been if this technique had not been used; a comparison was mode between the two experimental errors and the efficiency was calculated. Confounding in blocks of 9 units has presented a gain in precision of about 20% when compared with the completely randomized design. Eficiência do delineamento fatorial 3³, em blocos de 9, em uma série de experimentos de adubação do algodoeiro1 Efficiency of a 3³ factorial design for cotton fertilizer experiments Wanderley Rinaldo VenturiniI; Joassy de Paula Neves JorgeII IEngenheiro-agrônomo IILicenciada em Matemática, Seção de Técnica Experimental, Instituto Agronômico RESUMO Êste trabalho estuda a eficiência do delineamento fatorial 3³, em blocos de 9, em relação ao delineamento completamente casualizodo. Utilizaram-se cêrca de 260 experiências de adubação de olgodoeiro, realizadas nos anos de 1957/58, 1958/59 e 1959/60, em diferentes locais escolhidos, os quais abrangeram os principais tipos de solo cultivado com algodão no Estado de São Paulo. O confundimento em blocos de 9 foi, em média, 20% mais eficiente que o delineamento sem restrição. SUMMARY The purpose of this work was the study of the efficiency of a 3³ factorial design, confounded in blocks of 9 units, in comparison with the completely randomized design. Approximately 300 cotton experiments were conducted during the years of 57/58, 58/59, 59/60 on different kinds of soils of the State of São Paulo. From the results of the experiments in which confounding was employed, we estimated what the experimental error would have been if this technique had not been used; a comparison was mode between the two experimental errors and the efficiency was calculated. Confounding in blocks of 9 units has presented a gain in precision of about 20% when compared with the completely randomized design. Texto completo disponivél apenas em PDF. Full text available only in PDF format. LITERATURA CITADA Recebido para publicação em 28 de maio de 1962. 1 Os autores agradecem à Seção de Algodão do Instituto Agronômico, que gentilmente cedeu os dados originais para o presente trabalho. 1. COCHRAN, W. G. &. COX, G. M. Experimental Design. 2.Ş edição. New York, John Wiley & Sons, Inc., 1957. 611p. Experimental Design 1957 COCHRAN W. G. COX G. M. 2.  FISHER, R. A. The Design of Experiments. Edinburgh, Oliver and Boyd, 1937. 260p. The Design of Experiments 1937 FISHER R. A. 3.  NEVES, O. SILVEIRA, FRAGA JR., C. G. [e outros] Ensaios de adubação do algodoeiro. Campinas, Instituto Agronômico, 1960. 33p. (Boletim n.° 1 14). Ensaios de adubação do algodoeiro 1960 NEVES O. SILVEIRA FRAGA JR. C. G.