ABSTRACT Considerable attention has been given to the development of new nutritional management strategies that can contribute to banana production be overestimated. The present study was motivated by the possibility that fertilizer application in front of the daughter plant might be more effective than application to the total banana production area. This study aimed to determine the most suitable site for soil collection to evaluate the chemical properties when fertilizer is applied in front of the daughter plant; to evaluate the efficacy of organic-mineral fertilizer in terms of soil nutrient availability, and to evaluate the effect on banana production. The experiment was conducted in three consolidated areas of banana plantation in Santa Catarina State. The effects of the combination of two main factors were evaluated: three fertilizer sources (mineral, mineral + organic compost or organic-mineral) and two application management (total area or in front of the plants), together with time (three years) and location (three municipalities). Each treatment was evaluated using a grid containing 20 banana plants (spaced at 2.5 × 2.5 m), with three replications of two plants in the central part. The experiment was arranged in a completely randomized design with three replicates. The use of a mineral source reduced the pH over the years, regardless of the application technique. Application of fertilizers in front of the daughter plant increased available P and K in the soil, compared to the application of fertilizers to the total area “uniformly distributed between banana planting lines and between plants”. In addition, the increase in soil P content was higher using organic-mineral sources. The nutrient contents in the banana leaves did not differ according to the fertilization source. The application of fertilizers in front of the daughter plant optimized banana fertilization and increased fruit production. Under these fertilization conditions, soil for chemical analyses should be collected at around 0.70 m from the site of fertilizer application.
Protocolos de micropropagação de plantas possibilitam a produção de mudas isentas de pragas e doenças. No presente trabalho, objetivando a otimização da micropropagação do abacaxizeiro [Ananas comosus (L.) Merril], foram avaliados três fatores: 1) sistema de imersão (temporária por frascos duplos em erlenmeyers de 2 L ou permanente); 2) meio de cultura (suplementado, ou não, com Ácido Giberélico); 3) classe de altura de brotos. Os efeitos na taxa de regeneração (número de novos brotos para cada 1 g de massa fresca (MF) de microbrotos inoculada), na MF por broto, e na sobrevivência dos brotos foram avaliados. Interações significativas (p<0,05) foram observadas na taxa de regeneração, e efeitos simples (p<0,05) foram detectados na MF por broto. Todos os tratamentos resultaram em sobrevivência de mudas superior a 95% na aclimatização. Concluiu-se que a combinação do sistema de imersão temporária em frascos duplos e o meio de cultura isento de AG3 resultou na otimização do protocolo regenerativo. Esta combinação também demonstrou resposta positiva em um sistema de imersão temporária usual em biofábricas, que utiliza frascos duplos em garrafas PET de 5L.
Micropropagation based techniques enable the mass production of pest- and disease-free stock plants. Aiming at optimizing pineapple [Ananas comosus (L.) Merril] micropropagation, a complete randomized experiment with three factors was established: immersion system (2 L twin flasks temporary immersion and permanent immersion); culture medium (supplemented or not with GA3); and shoot height class. The effects on regeneration rate (number of new shoots per 1 g fresh mass (FM) of inoculated microshoots), FM per shoot, and shoot survival were evaluated. Significant interactions (p<0.05) were observed in the regeneration rate, and simple effects (p<0.05) were detected for FM per shoot. All treatments resulted in a survival rate higher than 95%. Altogether, it was found that 2 L twin flasks temporary immersion and MS culture medium free of GA3 allowed the optimization of the protocol used. This treatment was tested with positive response in a biofactory system that uses sterile plastic bottles (5 L).