Acclimatization of micropropagated seedlings of pineapple cultivars on organic substrates

Fusariosis constitutes an important hindrance to pineapple farming in Brazil. The cultivars resistant to fusariosis, ‘Vitoria’ and ‘Imperial’, from in vitro culture, are an alternative for crop management. This work evaluates the veg­etative performance of pineapple cultivars propagated by tissue culture in response to the use of organic sub­strates, different in nature and proportion. The experimental design was a completely randomized block, arranged in a 3×5 factorial scheme, with three pineapple cultivars (‘Perola’, ‘Vitoria’, and ‘Imperial’) and five substrates [ORG: Organoamazon®, organic compound; SS: Standard Substrate, soil + sand (1:1 v/v); SS + M + C: SS + sheep manure (M) + carbonized rice husk (C) (2:1:1 v/v); SS + M (3:1 v/v); SS + C (3:1 v/v), unfolded in mean contrasts]. The variables analyzed were shoot and root growth and shoot nutrient content. The vegetative perfor­mance of cultivars, considering the increase of shoot dry weight in the most responsive substrate, was:       ‘Perola’ > ‘Vitoria’ > ‘Imperial’. Substrate ORG promoted higher increases in shoot dry weight (259%) and root density (116%) compared to the average of the other substrates. The growth promoted by ORG resulted in higher N, P, K, Ca, and Mg content in pineapple plants. Substrates ORG and SS + M + C are recommended for acclimatiza­tion of in vitro propagated pineapple seedlings in the period of ex vitro seedling acclimatization.