Alocação de biomassa e a distribuição de raízes do híbrido interespecífico de palma de óleo (Elaeis o/e/fera x Elaeis guineensis).

Abstract

Brazil has an extensive area with climate and soil suitable for oil palm planting. However, production in part of this area has been limited by the occurrence of the Fatal Yellowing (FA) anomaly, whose initial symptom is rotting of absorption roots. This symptom may be more severe in oil palm genetic materials that have a reduced root system. We evaluated morphological characteristics of roots and aboveground parts of seedlings of three oil palm genotypes with different degrees of resistance to AF: Tenera (sensitive), Caiaué (resistant) and Interspecific Hybrid (resistant). The Interspecific Hybrid showed higher fine and very fine root mass values compared to Caiaué (155 and 99%, respectively) and Tenera (228 and 94%, respectively). The Interspecific Hybrid also showed higher values of fine and very fine root length compared to Caiaue (155 and 99% respectively) and Tenera (228 and 94% respectively). In another study we evaluated the belowground biomass in a commercial plantation of interspecific oil palm hybrid (Elaeis oleifera cortês x Elaeis guineensis jacq.), cultivar BRS Manicoré, in the municipality of Moju, northeastern Pará state. Root samples were obtained by collecting monoliths in trenches 4 meters long, 50 cm wide and 290 cm deep. Monoliths were collected in 8 layers (2 - 15, 2 - 30 and 4 of 50 cm depth) and in each layer, 8 monoliths measuring 50 cm long, 30 wide and the height according to the layer collected were collected. In the laboratory, the roots were classified according to their diameter into primary (^5.0 mm), secondary (1-4.9 mm), tertiary (0.5 - 0.9 mm) and quaternary (0.25 - 0.49 mm). The depth of 15-30 cm concentrates more than 50% of the total DMS (50.77% TP and 59.91 % TC), and of these, 81.49% of the DMS is from primary roots. Tertiary roots represent 8.96% of the total DMS of TP and 4.85% of TC and the amount of quaternary roots in the interplant region is 78.05% greater than the amount found in the carry-over region. The oil palm crop with 8 years old presents a higher total root biomass than seasonal crops, secondary vegetation, Traditional crop, Passion fruit crop and black pepper crop.