IBA levels and substrates in the rooting of UENF/CALIMAN 02 hybrid papaya minicuttings in a semi-hydroponic system

Abstract Mini-cutting is a technique with large applications in various crops, mainly due to the increase in the percentage and quality of adventitious roots, reducing time for the formation of clonal seedlings. The aim of this study was to evaluate IBA levels and substrates on the rooting of UENF/CALIMAN 02 hybrid papaya mini-cuttings. To perform the experiment, papaya mini-cuttings were taken from mother plants grown in pots in greenhouse, induced to produce shoots through pruning and growth regulator applications. Mini-cuttings were fixed in vermiculite or coconut fiver substrates placed in alveolate trays with 4.5x4.5x5.0 cm cells, and styrofoam trays were placed in plastic trays where different IBA levels were added in a modified Hoagland solution. After 45 days, rooted buds were transplanted to plastic pots of 600 mL of volume with soil, sand, well-cured bovine fertilizer, in the proportion of 3:1:1, remaining for 45 days. When they were taken from pots, roots were carefully washed, and the length of shoots, length of the largest root, dried mass of shoots and radicular system and root percentage were measured. The experiment was set up in a randomized complete block 5 x 2 factorial design, with 5 IBA levels: 0; 2.5; 5.0; 7.5 and 10 mg L-1, two substrates: vermiculite and coconut fiber, three replicates, with six plants per replicate. IBA levels of 5.0 mg L-1 and substrate vermiculite are the most adequate for the rooting of ‘UENF/CALIMAN 02’ papaya mini-cuttings in semi-hydroponic system in alveolate styrofoam trays with 4.5x4.5x5.0 cm cells. Resumo A miniestaquia é uma técnica com grandes aplicações em várias culturas, devido, principalmente, ao aumento dos porcentuais e qualidade de enraizamento adventício, reduzindo o tempo para a formação da muda clonal. O objetivo deste trabalho foi avaliar níveis de ácido indolbutírico (AIB) e substrato no enraizamento de miniestacas de mamoeiro híbrido UENF/CALIMAN 02. Para a realização do experimento, as miniestacas de mamoeiro foram retiradas de plantas matrizes cultivadas em vasos, em casa de vegetação, induzidas a produzir brotos por meio de podas e aplicações de reguladores vegetais. As miniestacas foram afixadas em substrato vermiculita ou fibra de coco em bandejas alveoladas de isopor com células de 4,5x4.5x5,0 cm. As bandejas de isopor foram então colocadas em bandejas plásticas contendo solução de Hoagland modificada onde foram adicionados diferentes níveis de AIB. Após 45 dias, os brotos enraizados