Effect of initial stem nodal cutting strength on dry matter production and accumulation in cassava (Manihot esculenta Crantz)

This study was done to determine the effect of initial node strength on dry matter yield of cassava. Studies were conducted at the Waterloo Research Campus, University of Trinidad and Tobago using the sets of Mexican variety (Mx) at 6 months with 1 to 3 nodes, 4 to 9 cm, and dry matter of 6 to 15 g/set. The crop was established at 60 × 80 cm and treated with a compound NPK fertilizer. Growth analysis (functional approach) was carried from 20 to 340 Days after emergence (DAE), and the best fit polynomial regression applied. The results indicated that tuberization started after 120 DAE and tuber dry weight increased with increasing set size (YTDW = -1177 + 9.90D 1.26 -2 D 2 + 37.7N 2 ). The 3 node sets produced (P > 0.05) the highest tuber yield. The leaf area ratio (LAR) showed (P > 0.001) a quadratic response (Ylar = 12.8 1.94 H 2.39 N + 0.08 H 2 + 0.18 N*H), peaked at 2 g/cm 2 /day 1 , and declined at harvest. Both the net assimilation rate (NAR) and the relative growth rate (RGR) were not affected by the number of nodes, however, the NAR peaked 0.046 g/m 2 /day at 60 DAE. The initial strength of 3 nodes sets proved to be superior to the single node sets.