RESUMOA falta de estudos que indiquem as necessidades nutricionais de muitas orquídeas resulta na realização de práticas de adubação embasadas em experiências práticas e que não necessariamente atendem às demandas nutricionais de todas as espécies. O objetivo deste trabalho foi avaliar a influência da adubação mineral e orgânica e suas respectivas combinações no desenvolvimento da orquídea Cattlianthe 'Chocolate drop'. As mudas desse híbrido foram obtidas por clonagem in vitro, e cultivadas em condição de casa de vegetação, utilizando potes plásticos com capacidade de 1 L contendo como substrato uma mistura de casca de pinus e carvão (4v:3v). Os tratamentos avaliados foram: sem adubação (testemunha), fertirrigação com fertilizante mineral ultra solúvel (FMU), mistura de torta de mamona e farinha de ossos (TM+FO), bokashi (BOK), FMU + mistura de torta de mamona e farinha de ossos [FMU+(TM+FO)], FMU + bokashi (FMU+BOK), mistura de torta de mamona e farinha de ossos + bokashi [(TM+FO)+BOK], FMU + mistura de torta de mamona e farinha de ossos + bokashi [FMU+(TM+FO)+BOK]. Após oito meses do início das adubações foram avaliados o desenvolvimento da parte aérea e o acúmulo de nutrientes. O tratamento FMU+BOK foi significativamente superior ao tratamento sem adubação, com incrementos aproximados de 54, 42, 33 e 78% da massa seca da parte aérea, comprimento da parte aérea, comprimento médio radicular e área foliar, respectivamente. A combinação entre adubação mineral e orgânica favoreceu o desenvolvimento de plantas do híbrido de Cattlianthe 'Chocolate drop'.Palavras-chave: Orchidaceae, nutrição, fertilização, parte aérea, desenvolvimento vegetativo. ABSTRACT Mineral and organic fertilization influence on the development of Cattlianthe 'Chocolate drop'The lack of studies showing nutritional requirements of many orchids results in adoption of fertilization practices based on practical experience, which may not meet the nutritional requirements of all species. The objective of this study was to evaluate the influence of mineral and organic fertilizers and their combinations on growth of orchid Cattlianthe 'Chocolate drop'. Seedlings of this hybrid were obtained by in vitro cloning, and grown in a greenhouse condition using plastic pots with capacity of 1 L containing as substrate a mixture of pine and bark (4v:3v). The evaluated treatments were: without fertilization (control), ultra-soluble mineral fertilizer ( Eight months after beginning of fertilizations, development of the aboveground part and accumulation of nutrients were evaluated. The FMU+BOK treatment was significantly superior to treatment without fertilization, with approximate increments of 54, 42, 33 and 78% over the dry weight of the aboveground part, aboveground part length, root length and leaf area, respectively. The combination of mineral and organic fertilization favored the growth of hybrid plants of Cattlianthe 'Chocolate drop'.

In vitro cultivation is a highly important biotechnological method widely used for the production of orchid seedlings, but it is necessary to study the suitability of the nutrients used in different kinds of formulation, as the nutritional requirement varies according to the species. The objective was to evaluate different concentrations of iron in the in vitro cultivation of Schomburgkia crispa Lindl seedlings. Seedlings were obtained from seeds germinated in vitro. Modified MS culture medium was used with half of the macronutrient concentration. The micronutrients were added according to the original formulation, except for the iron which was added from a stock solution of FeEDTA (FeSO4.7H2O: 5.6 g L-1 and EDTA: 7.48 g L-1) at 0.0; 2.5; 5.0; 7.5; 10.0 and 12.5mL L-1. At 200 days after seedling transplantation, shoot height, root length, number of leaves, shoot number, leaf length, leaf width, aerial and root dry mass, chlorophyll a, b and carotenoids content were evaluated. A completely randomized design was used, with six treatments and ten replicates of five seedlings. Regression analysis was performed at 5% of significance. The increase in iron concentration caused a reduction in root length and an increase in the number of leaves and shoots. The concentration of 4.13 mL L-1 of FeEDTA was the one that provided the best in vitro growth of S. crispa plants. High concentrations of iron caused a reduction of initial development, but stimulated an increase in the number of shoots.