Effects of season of ratooning and field position of seedling ratoon clumps on selection in sugarcane (Saccharum officinarum)

Abstract

Field experiments were conducted during 2000–06 to study the position of seedlings in the field (border and interior) and seasons of ratooning in the ground nursery using 12 crosses of sugarcane (Saccharum officinarum). Two hundred sixty two seedlings in each cross were ratooned during winter (December) and spring (March). Seedling ratooned clumps were scored for number of millable canes (NMC), stalk diameter, stalk height and hand refractometer Brix (HR Brix) during next October. Selected clones were evaluated at different stages of selection (C1 to C4). Ratooning during winter season resulted in reduction in NMC and stalk length, whereas increase in HR Brix of the population in comparison to spring ratooning. There was no effect of ratooning season on stalk diameter. Border effects on winter ratooned clumps resulted in increase in mean performance of all the traits except HR Brix. In spring ratooned clumps border effect resulted in improvement in all traits except stalk length. Results indicated that selection was more effective in spring ratooned and from interior field positioned seedlings. Sugarcane breeders should not be tempted to select vigorous border field positioned seedlings.