Estudo da aclimatização de plântulas de variedades locais de mandioca (Manihot esculenta Crantz) produzidas in vitro

Abstract

Cassava is a tropical crop with an important role in the food security of the African population. In Mozambique, where more than 50% of the population depends on this crop for their daily food, the occurrence of viruses (CBSD and ACMD) is a limiting factor in production, resulting in large yield drops. Tissue culture is one of the effective methods of eliminating viruses and rapid multiplication of material, however, the success of this methodology depends on the acclimatization of seedlings before transfer to the field. This work aimed to study the appropriate procedures for acclimatization of cassava seedlings produced in vitro. The selected varieties were "Chinhembwe" and "6 Months". The trial was set up in a greenhouse at IIAM, between February and April 2006. Six treatments were used [presence or absence of 2 g/L of NPK 12:24 :12 in 3 types of substrates (SE = sandy soil+Animal manure; HV = Hygromix+Vermicilite and VE =Vermiculite+Animal manure)], completely randomized in a factorial scheme. to achieve the objectives, survival rates and growth parameters were evaluated (AF = leaf area, CR = root length, PFF = fresh weight of leaves; PFR = fresh weight of roots; NF = number of leaves and NR = number of roots). The type of substrate used for transplantation affected the survival of plants from in vitro propagation, with HV substrate (HV-O and HV-l) showing higher rates (<35%). In terms of growth, only the NF parameters; NR for both varieties) and CR (for the "6 Months" variety) were significantly influenced by substrates, where HV and SE were superior to VE. The NPH 12:24:12 factor influenced plant growth only in the "6 Months", in which the application of NPK 12:24:12 significantly benefited root development (TRADUÇÃO NOSSA)