Efficiency of Yield Selection in Cassava Populations under Different Plant Spacings
1982
Kawano, Kazuo | Tiraporn, Charn | Tongsri, Somsak | Kanō, Yoshiaki
Cassava (Manihot esculenta Crantz) genotypes were evaluated in a high productivity environment for single-plant root yield and harvest index (proportion of root weight to total plant weight) in segregating populations and single-row trials at different plant spacings and for unit-area yield in a replicated large-plot trial to assess efficiency of selection. Broad-sense heritability for single-plant yield in segregating populations was much higher than that for harvest index irrespective of spacing. The correlation of single-plant yield in segregating populations with unit-area yield was invariably lower than that of harvest index with unit-area yield. Thus, harvest index is a better selection criterion than single-plant yield in segregating populations or in single-row trials when the final selection objective is unit-area yield. Intergenotypic competition appeared to be the major cause for a low correlation between single-plant yield and unit-area yield. Spacing of 1 × 2 m in segregating populations and a distance of 2 m between rows in single-row trials were more efficient than other spacings.
显示更多 [+] 显示较少 [-]