Efficiency of first clonal trial selection using different plot sizes.

MILLIGAN S; BALZARINI M

Agronomy Projects

Louisiana State University

Lugar: Baton Rouge, USA ; Año: 1999 p. 64 - 70

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Each year the LAES Sugarcane variety development program select among 50,000 individuals up to 3000 clones to advance to the first clonal trials (first line trials). Each clone is planted using 2 stalks into single row plots 1.82 m long with a 60 cm gap or alley way between plots within a row. The following year the clones are subjectively assessed for cane yield. The clones are also screened for disease, pith, Brix and other characteristics.  From the initial 3000 clones about 1000 will advanced to the second clonal trials. Secand clonal trials are planted with six stalks into single row, 4.88 m long plots using 120 cm gaps between plots within the row. The breeding program estimates yields using single row plots 4.88 m long with 120 cm gaps in the next three planted stages after the second clonal trial. Single row 1.82 m plots typically provide about two stools of cane to assess the cane yield potential. Since observable and-row effects (shorter cane) are detectable for about one meter from the end, the entire 1.82 m plot is subject to an end-row border effect. The use of the larger plots after the first clonal stage indicates the assumption that larger plots such as the 4.88 m plots  better assess yield than the 1.82 m plots used in the first clonal trial. The effect of the plot size on the quality of the yield estimate has not been appraised and was the objective of this study.