Substratos alternativos ao xaxim e adubação de plantas de orquídea na fase de aclimatização Alternative substrates to xaxim and fertilization on orchids plantlets acclimatization phase

Objetivou-se estudar substratos e adubação em plantas de orquídea da espécie C. loddgesii "Alba" x C. loddgesii "Atibaia". Plantas oriundas de cultivo in vitro foram transplantadas para bandejas coletivas contendo pó de xaxim e aclimatizadas em casa de vegetação. Após seis meses, quando as plantas tinham de 3,0 a 5,0cm de comprimento, foram transferidas para bandejas de plástico com 24 células de 150cm³ cada contendo os substratos brita no 0, casca de arroz carbonizada (CAC), xaxim desfibrado e fibra de piaçava e submetidas a adubações semanais com Biofert Plus® (5,0mL L-1), Dyna-Grow® (2,5mL L-1) e formulação elaborada. Após 12 meses, verificou-se que os melhores substratos para plantas da orquídea C. loddgesii "Alba" x C. loddgesii "Atibaia" são casca de arroz carbonizada e fibra de piaçava, e melhores respostas à adubação são obtidas com o adubo foliar Biofert Plus®.This paper was aimed at studing different substrates and fertilization for the development of C. loddgesii 'Alba' x C. loddgesii 'Atibaia' orchid species. Seedlings from in vitro culture were transplanted to plastic trays containing xaxim powder. After 6-months of acclimatization inside a greenhouse, plantles measuring beetwen 3.0 to 5.0cm length were transferred to 24 cell trays with a volume of 150cm³. Four substrates were tested (broken stone number 0, carbonized rice hulls, defibered xaxim and piassava fiber with tree different fertilizations (Biofert Plus®, Dyna Grow® and a specific formulation developed for this work). Pure water was tested as control. After 12-months of growth the best treatments for the acclimatization of in vitro produced C. loddgesii 'Alba' x C. loddgesii 'Atibaia' orchid plantlets were carbonized rice hulls or piassava fiber substrates combined with leaf fertilizer Biofert Plus®.