Characteristics of Dry Matter Accumulation and Effect of Fertilizer Application in Cassava

Abstract

The field trials were conducted at two sites nearby the Tropical Center to investigate the influence of variety and fertilization on dry matter formation and accumulation of cassava. Two varieties of newly developed SC5 and conventional SC205 were used with five fertilization treatments including NP (1.0:0.4:0), NK (1:0:1), PK (0:0.4:1.0), NPK (1.0:0.4:1.0) and CK (no fertilizer application). Results indicated that the dry matter accumulation patterns were similar for both varieties. From transplanting to early August, dry matter accumulation mainly allocated in above-ground parts. When tubes started rapidly growing from mid August, the allocation of dry matter accumulation was shifted from above-ground to underground parts, and there was a difference between two varieties in accumulating velocity and distributing proportion of biomass. SC5 had larger crown with many earlier developing branches and leaves compared with SC205, resulting in more biomass accumulation in above-ground parts, thus reducing harvesting index. For fertilizer application, N was the most significant factor to increase dry matter, following K and P. Combining application of NPK (1.0:0.4:1.0) significantly enhanced accumulating velocity of dry matter and tube yields of cassava. There were some difference between two varieties in dry matter accumulation depended on NPK fertilizer application, and probably related to their nutrient demands and root developing level.