Leaf density profile and efficiency in partitioning dry matter among high and low yielding cultivars of cassava (Manihot esculenta crantz)

Abstract

Abstract Leaf area density, and efficiency in partitioning dry matter for tuber growth were studied using six cultivars of cassava which differ in their yielding ability. The cultivars of the low yielding group maintained either sub-optimal ( 4) levels of leaf area index during the major part of growth period and this adversely affected their light utilization efficiency. A significant negative correlation ( r = −0.78) was observed between leaf area density and light transmission ratio. For better light interception and utilization, a leaf area index of 2.5–3.5 was found to be optimum for cassava. A significant difference in partitioning dry matter (DM) for tuber growth was noticed among the cultivars tested, which varied from 0.3 to 0.7 per unit of DM produced. The short-statured cultivar Ci 590 was more efficient in utilizing DM for storage root growth (harvesting efficiency = 70%). The leaf density profile suggested that the productivity of Ci 590 could be raised substantially by increasing plant density. The distribution of DM between shoot and tuber showed a linear relationship with total biomass. However, the harvest index reached a more or less constant value after the fourth month, with the onset of tuber bulking, till final harvest.